INTRODUCTION — Prostate cancer screening involves testing for cancer in men who have no symptoms of the disease. This testing can find cancer at an early stage, when it may be more easily and effectively treated. However, medical experts disagree about whether prostate cancer screening is right for all men, and it is not clear if the benefits of screening outweigh the risks.
This topic review is designed to discuss the advantages and disadvantages of prostate cancer screening. Men should talk with their healthcare provider to decide what is best in their individual situation.
WHAT IS PROSTATE CANCER? — Prostate cancer is a malignancy of the prostate, a small gland in men that is located below the bladder and above the rectum (show figure 1). The prostate produces seminal fluid that helps carry sperm during ejaculation.
According to the American Cancer Society, about 234,000 men in the United States will be diagnosed with prostate cancer in 2006, and over 27,000 will die from this disease. Prostate cancer is the second most commonly diagnosed malignancy after skin cancer.
Although many men are diagnosed with prostate cancer, most of them do not die from their cancer. While the lifetime risk of being diagnosed with prostate cancer is about 17 percent, only 3 percent of men die from the disease. Furthermore, autopsies show that 30 percent of men 50 years and older die with undiagnosed prostate cancer. This suggests that prostate cancer may grow so slowly that many men die of other causes before they even develop symptoms of prostate cancer.
RISK FACTORS
Age — All men are at risk for prostate cancer, but the risk greatly increases with older age. Doctors rarely find prostate cancer in men younger than 50 years old.
Ethnic background — Black men develop prostate cancer more often than white men. They also are more likely to die of prostate cancer than white men.
Family medical history — Men who have a first-degree relative (a father or brother) with prostate cancer are more likely to develop the disease.
Diet — A diet high in animal fat may increase a man's risk of prostate cancer.
PROSTATE CANCER SCREENING — Prostate cancer screening involves two tests: A physical test called a digital rectal exam (DRE) A blood test that measures prostate specific antigen (PSA).
Digital rectal examination — The DRE is performed by a healthcare provider in the office by inserting a gloved, lubricated finger into the rectum to feel for any lumps or irregularities in the prostate gland (show figure 2). DRE can detect some cancers that are missed by the PSA test. However, because it is not possible to reach all areas of the prostate, some tumors can go undetected using this screening method alone. Additionally, microscopic prostate cancers are impossible to detect by touch, no matter where they are located.
Prostate specific antigen — PSA is a protein produced by the prostate. The serum PSA test measures the amount of PSA in a sample of blood. Although many men with prostate cancer have an elevated PSA concentration (greater than 4.0 ng/mL), a high level does not necessarily mean there is a cancer. The most common cause for an elevated PSA is benign prostatic hyperplasia (BPH), a noncancerous enlargement of the prostate. Other benign causes include prostate infection (prostatitis) and trauma. Trauma may be caused by bicycle riding or sexual activity; thus, the PSA should not be measured for 48 hours after these activities.
Generally speaking, the higher the PSA, the greater the chance that a cancer is present. However, in some studies, over 20 percent of men with prostate cancer had a normal PSA (false-negative test), while up to 40 percent of men without cancer had an abnormal PSA (false-positive test). Overall, only 30 percent of men with abnormal values will have prostate cancer.
Thus, the PSA test is not 100 percent accurate. False-negative results can delay diagnosis until the cancer is more advanced and less likely to be curable. False-positive results, which are common, can cause anxiety and lead to further testing that is more expensive to perform and is uncomfortable for patients.
Refinements in PSA blood testing such as measuring PSA velocity (rate of change over time), PSA density (PSA per volume of prostate tissue), free (unbound) PSA, and complex (bound to protein) PSA are intended to increase the accuracy of PSA tests, but there is not general agreement about the additional benefits of these tests.
If the DRE or PSA test is positive — A positive DRE or PSA test is not a reason to panic; benign conditions are the most common causes for an abnormal test, particularly for PSA tests. On the other hand, a positive test should not be ignored. Other tests, like transrectal ultrasound and prostate biopsy, are needed to evaluate a positive DRE or PSA.
Transrectal ultrasound — Transrectal ultrasound can be done in an office, and no sedation or anesthesia is needed. A small probe, about the size of a finger, is inserted into the rectum, and uses sound waves that bounce off the prostate to create an echo. A computer translates these echoes into an image (called a sonogram) of the prostate. About 80 percent of cancers have an abnormal ultrasound image. Transrectal ultrasound can also help to guide a surgeon to biopsy any area that appears abnormal.
Prostate biopsy — Prostate biopsy is also performed without sedation or anesthesia. It is done by inserting a small device into the rectum that can take a small sample of any suspicious areas (found either with DRE or ultrasound). Tissue samples are also taken from the base, middle, and tip of each side of the prostate. Some men experience temporary, mild rectal bleeding or blood in the urine or semen after this procedure. Rarely, biopsy can cause heavy bleeding or infection.
Up to one in five men with a negative result on an initial biopsy may have cancer diagnosed after subsequent biopsies. In addition, prostate biopsy can detect clinically unimportant cancers that are unlikely to cause illness or death; subsequent treatment for these cancers can ultimately cause more harm than good.
Summary — No screening test for prostate cancer is perfect. Experts who favor it suggest that the best screening strategy combines DRE with PSA testing, followed by transrectal ultrasound-guided prostate biopsy if either test is positive.
PROS AND CONS OF SCREENING — There are a number of arguments for and against prostate cancer screening.
Arguments for screening — Experts in favor of prostate cancer screening cite the following arguments: Even though many men with prostate cancer have nonaggressive tumors and do not die of the disease, the cancer is so common that a substantial number of men die from the cancer every year and many more suffer from the complications of advanced disease. For men with an aggressive prostate cancer, the best chance for curing it is probably by finding it at an early stage through screening and then treating it with surgery or radiation. Studies have shown that men who have prostate cancer detected by PSA screening tend to have earlier-stage cancer than men who have a cancer detected by other means. (See "Patient information: Advanced prostate cancer" and see "Patient information: Treatment for early prostate cancer"). The five-year survival for men who have prostate cancer confined to the prostate gland (early stage) is nearly 100 percent; this drops to 30 percent for men whose cancer has spread to other areas of the body. Chemotherapy and radiation therapy are relatively ineffective once prostate cancer has spread outside the prostate gland. The available screening tests are not perfect, but they are fairly good compared with screening tests for some other cancers, and they are easy to perform. The death rate due to prostate cancer has declined in recent years. This may be due to increased screening or improvements in prostate cancer treatment, particularly for advanced cancers. The death rate may also have declined due to changes in the ways that physicians complete death certificates.
Arguments against screening — The main argument against screening is that it is not clear if screening and treatment help men live longer and/or avoid the complications of advanced prostate cancer. No well-performed studies have determined that prostate cancer screening in the general population saves lives. Studies are currently underway to answer this important question, but the results may not be available for some time.
Other arguments have also been made against screening: Because of the relatively high number of false-positive DRE and PSA tests, a number of screened men will undergo unnecessary further testing with transrectal ultrasound and prostate biopsy. These secondary tests are relatively safe to perform, but they are not totally without side effects, and they add further costs. The side effects of treatment for early prostate cancers that are detected with screening may be substantial. Surgery and radiation therapy are the most popular therapies, and both can cause erectile dysfunction, urinary incontinence, and bowel problems. Although there are some tools to predict which cancers are more aggressive than others, these tools are not always accurate.
Many prostate cancers detected with screening are unlikely to cause death or disability. Thus, a number of men will have to experience the side effects of surgery and radiation for cancers that would never have bothered them had they gone undetected. In other words, even if the screening process works and a cancer is detected, it is not clear in all cases that the treatment is more beneficial than harmful.
PREVENTION OF PROSTATE CANCER
Supplements — Studies suggest that vitamin E and selenium supplements may protect against prostate cancer, but there is not enough evidence to recommend these supplements to all men.
Medications — Finasteride (Proscar®) has been shown to reduce the risk of developing prostate cancer by about 25 percent. However, aggressive cancers were diagnosed more frequently during the first year in men treated with finasteride than in those taking a placebo (look-alike substitute that contains no medication) pill. The reasons for this finding are not clear. It is not clear if finasteride should be offered to men at high risk for prostate cancer.
RECOMMENDATIONS
Professional organizations — Major medical associations and societies have issued conflicting recommendations regarding screening, making it difficult for an individual to decide if screening is right. The United States Preventive Services Task Force [2] and many European cancer societies have not endorsed routine serum PSA screening for the early detection of prostate cancer, while the American Cancer Society [3] and American Urological Association [4] do recommend screening. With currently available data, it is not possible to determine if the benefits of screening outweigh the significant risks associated with treatment.
A number of studies are expected to be completed over the next several years that should help clarify this controversy. In the meantime, the American Cancer Society, American Urological Association, and American College of Physicians recommend that men have an open discussion with their clinician.
The best way to decide if prostate cancer screening is right is to: Consider individual prostate cancer risk factors Know the potential benefits and harms of screening, diagnosis, and treatment Talk to a clinician about concerns or questions.
For men who choose screening — If a man chooses to have screening, he should begin at age 50. Men with risk factors for prostate cancer (such as black men or a man with a father or brother who had prostate cancer) may want to begin screening at the age of 45.
Screening should continue yearly once it is started, though less frequent testing may be appropriate for some men with a low PSA. For men who choose screening, we suggest that those with a PSA level below 1.0 ng/mL consider having PSA testing every four years and that those with a higher PSA level consider having PSA testing annually. We suggest that men who choose screening have an annual digital rectal exam, regardless of their PSA level.
Screening not recommended — Screening should not be performed in men who are 75 years and older or who have serious health problems; these men are unlikely to live long enough to benefit from screening and/or treatment.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
1-800-4-CANCER
(www.cancer.gov/cancertopics/screening/prostate)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
National Comprehensive Cancer Network
(www.nccn.org/patients/patient_gls.asp)
American Cancer Society
1-800-ACS-2345
(www.cancer.org)
National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
US TOO! Prostate Cancer Education and Support
(www.ustoo.com/Early_Detection.asp)
[1-6]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Prostate cancer. National Cancer Institute. Web site: http://cancernet.nci.nih.gov/cancertopics/types/prostate.
2. Screening for prostate cancer: recommendation and rationale. Ann Intern Med 2002; 137:915.
3. Smith, RA, von Eschenbach, AC, Wender, R, et al. American Cancer Society Guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. CA Cancer J Clin 2001; 51:38.
4. Prostate-specific antigen (PSA) best practice policy. American Urological Association (AUA). Oncology (Williston Park) 2000; 14:267.
5. Whittemore, AS, Cirillo, PM, Feldman, D, Cohn, BA. Prostate specific antigen levels in young adulthood predict prostate cancer risk: results from a cohort of Black and White Americans. J Urol 2005; 174:872.
6. Carter, HB. Prostate cancers in men with low PSA levels--must we find them?. N Engl J Med 2004; 350:2292.
Friday, October 12, 2007
Prostate cancer screening
INTRODUCTION — Prostate cancer screening involves testing for cancer in men who have no symptoms of the disease. This testing can find cancer at an early stage, when it may be more easily and effectively treated. However, medical experts disagree about whether prostate cancer screening is right for all men, and it is not clear if the benefits of screening outweigh the risks.
This topic review is designed to discuss the advantages and disadvantages of prostate cancer screening. Men should talk with their healthcare provider to decide what is best in their individual situation.
WHAT IS PROSTATE CANCER? — Prostate cancer is a malignancy of the prostate, a small gland in men that is located below the bladder and above the rectum (show figure 1). The prostate produces seminal fluid that helps carry sperm during ejaculation.
According to the American Cancer Society, about 234,000 men in the United States will be diagnosed with prostate cancer in 2006, and over 27,000 will die from this disease. Prostate cancer is the second most commonly diagnosed malignancy after skin cancer.
Although many men are diagnosed with prostate cancer, most of them do not die from their cancer. While the lifetime risk of being diagnosed with prostate cancer is about 17 percent, only 3 percent of men die from the disease. Furthermore, autopsies show that 30 percent of men 50 years and older die with undiagnosed prostate cancer. This suggests that prostate cancer may grow so slowly that many men die of other causes before they even develop symptoms of prostate cancer.
RISK FACTORS
Age — All men are at risk for prostate cancer, but the risk greatly increases with older age. Doctors rarely find prostate cancer in men younger than 50 years old.
Ethnic background — Black men develop prostate cancer more often than white men. They also are more likely to die of prostate cancer than white men.
Family medical history — Men who have a first-degree relative (a father or brother) with prostate cancer are more likely to develop the disease.
Diet — A diet high in animal fat may increase a man's risk of prostate cancer.
PROSTATE CANCER SCREENING — Prostate cancer screening involves two tests: A physical test called a digital rectal exam (DRE) A blood test that measures prostate specific antigen (PSA).
Digital rectal examination — The DRE is performed by a healthcare provider in the office by inserting a gloved, lubricated finger into the rectum to feel for any lumps or irregularities in the prostate gland (show figure 2). DRE can detect some cancers that are missed by the PSA test. However, because it is not possible to reach all areas of the prostate, some tumors can go undetected using this screening method alone. Additionally, microscopic prostate cancers are impossible to detect by touch, no matter where they are located.
Prostate specific antigen — PSA is a protein produced by the prostate. The serum PSA test measures the amount of PSA in a sample of blood. Although many men with prostate cancer have an elevated PSA concentration (greater than 4.0 ng/mL), a high level does not necessarily mean there is a cancer. The most common cause for an elevated PSA is benign prostatic hyperplasia (BPH), a noncancerous enlargement of the prostate. Other benign causes include prostate infection (prostatitis) and trauma. Trauma may be caused by bicycle riding or sexual activity; thus, the PSA should not be measured for 48 hours after these activities.
Generally speaking, the higher the PSA, the greater the chance that a cancer is present. However, in some studies, over 20 percent of men with prostate cancer had a normal PSA (false-negative test), while up to 40 percent of men without cancer had an abnormal PSA (false-positive test). Overall, only 30 percent of men with abnormal values will have prostate cancer.
Thus, the PSA test is not 100 percent accurate. False-negative results can delay diagnosis until the cancer is more advanced and less likely to be curable. False-positive results, which are common, can cause anxiety and lead to further testing that is more expensive to perform and is uncomfortable for patients.
Refinements in PSA blood testing such as measuring PSA velocity (rate of change over time), PSA density (PSA per volume of prostate tissue), free (unbound) PSA, and complex (bound to protein) PSA are intended to increase the accuracy of PSA tests, but there is not general agreement about the additional benefits of these tests.
If the DRE or PSA test is positive — A positive DRE or PSA test is not a reason to panic; benign conditions are the most common causes for an abnormal test, particularly for PSA tests. On the other hand, a positive test should not be ignored. Other tests, like transrectal ultrasound and prostate biopsy, are needed to evaluate a positive DRE or PSA.
Transrectal ultrasound — Transrectal ultrasound can be done in an office, and no sedation or anesthesia is needed. A small probe, about the size of a finger, is inserted into the rectum, and uses sound waves that bounce off the prostate to create an echo. A computer translates these echoes into an image (called a sonogram) of the prostate. About 80 percent of cancers have an abnormal ultrasound image. Transrectal ultrasound can also help to guide a surgeon to biopsy any area that appears abnormal.
Prostate biopsy — Prostate biopsy is also performed without sedation or anesthesia. It is done by inserting a small device into the rectum that can take a small sample of any suspicious areas (found either with DRE or ultrasound). Tissue samples are also taken from the base, middle, and tip of each side of the prostate. Some men experience temporary, mild rectal bleeding or blood in the urine or semen after this procedure. Rarely, biopsy can cause heavy bleeding or infection.
Up to one in five men with a negative result on an initial biopsy may have cancer diagnosed after subsequent biopsies. In addition, prostate biopsy can detect clinically unimportant cancers that are unlikely to cause illness or death; subsequent treatment for these cancers can ultimately cause more harm than good.
Summary — No screening test for prostate cancer is perfect. Experts who favor it suggest that the best screening strategy combines DRE with PSA testing, followed by transrectal ultrasound-guided prostate biopsy if either test is positive.
PROS AND CONS OF SCREENING — There are a number of arguments for and against prostate cancer screening.
Arguments for screening — Experts in favor of prostate cancer screening cite the following arguments: Even though many men with prostate cancer have nonaggressive tumors and do not die of the disease, the cancer is so common that a substantial number of men die from the cancer every year and many more suffer from the complications of advanced disease. For men with an aggressive prostate cancer, the best chance for curing it is probably by finding it at an early stage through screening and then treating it with surgery or radiation. Studies have shown that men who have prostate cancer detected by PSA screening tend to have earlier-stage cancer than men who have a cancer detected by other means. (See "Patient information: Advanced prostate cancer" and see "Patient information: Treatment for early prostate cancer"). The five-year survival for men who have prostate cancer confined to the prostate gland (early stage) is nearly 100 percent; this drops to 30 percent for men whose cancer has spread to other areas of the body. Chemotherapy and radiation therapy are relatively ineffective once prostate cancer has spread outside the prostate gland. The available screening tests are not perfect, but they are fairly good compared with screening tests for some other cancers, and they are easy to perform. The death rate due to prostate cancer has declined in recent years. This may be due to increased screening or improvements in prostate cancer treatment, particularly for advanced cancers. The death rate may also have declined due to changes in the ways that physicians complete death certificates.
Arguments against screening — The main argument against screening is that it is not clear if screening and treatment help men live longer and/or avoid the complications of advanced prostate cancer. No well-performed studies have determined that prostate cancer screening in the general population saves lives. Studies are currently underway to answer this important question, but the results may not be available for some time.
Other arguments have also been made against screening: Because of the relatively high number of false-positive DRE and PSA tests, a number of screened men will undergo unnecessary further testing with transrectal ultrasound and prostate biopsy. These secondary tests are relatively safe to perform, but they are not totally without side effects, and they add further costs. The side effects of treatment for early prostate cancers that are detected with screening may be substantial. Surgery and radiation therapy are the most popular therapies, and both can cause erectile dysfunction, urinary incontinence, and bowel problems. Although there are some tools to predict which cancers are more aggressive than others, these tools are not always accurate.
Many prostate cancers detected with screening are unlikely to cause death or disability. Thus, a number of men will have to experience the side effects of surgery and radiation for cancers that would never have bothered them had they gone undetected. In other words, even if the screening process works and a cancer is detected, it is not clear in all cases that the treatment is more beneficial than harmful.
PREVENTION OF PROSTATE CANCER
Supplements — Studies suggest that vitamin E and selenium supplements may protect against prostate cancer, but there is not enough evidence to recommend these supplements to all men.
Medications — Finasteride (Proscar®) has been shown to reduce the risk of developing prostate cancer by about 25 percent. However, aggressive cancers were diagnosed more frequently during the first year in men treated with finasteride than in those taking a placebo (look-alike substitute that contains no medication) pill. The reasons for this finding are not clear. It is not clear if finasteride should be offered to men at high risk for prostate cancer.
RECOMMENDATIONS
Professional organizations — Major medical associations and societies have issued conflicting recommendations regarding screening, making it difficult for an individual to decide if screening is right. The United States Preventive Services Task Force [2] and many European cancer societies have not endorsed routine serum PSA screening for the early detection of prostate cancer, while the American Cancer Society [3] and American Urological Association [4] do recommend screening. With currently available data, it is not possible to determine if the benefits of screening outweigh the significant risks associated with treatment.
A number of studies are expected to be completed over the next several years that should help clarify this controversy. In the meantime, the American Cancer Society, American Urological Association, and American College of Physicians recommend that men have an open discussion with their clinician.
The best way to decide if prostate cancer screening is right is to: Consider individual prostate cancer risk factors Know the potential benefits and harms of screening, diagnosis, and treatment Talk to a clinician about concerns or questions.
For men who choose screening — If a man chooses to have screening, he should begin at age 50. Men with risk factors for prostate cancer (such as black men or a man with a father or brother who had prostate cancer) may want to begin screening at the age of 45.
Screening should continue yearly once it is started, though less frequent testing may be appropriate for some men with a low PSA. For men who choose screening, we suggest that those with a PSA level below 1.0 ng/mL consider having PSA testing every four years and that those with a higher PSA level consider having PSA testing annually. We suggest that men who choose screening have an annual digital rectal exam, regardless of their PSA level.
Screening not recommended — Screening should not be performed in men who are 75 years and older or who have serious health problems; these men are unlikely to live long enough to benefit from screening and/or treatment.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
1-800-4-CANCER
(www.cancer.gov/cancertopics/screening/prostate)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
National Comprehensive Cancer Network
(www.nccn.org/patients/patient_gls.asp)
American Cancer Society
1-800-ACS-2345
(www.cancer.org)
National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
US TOO! Prostate Cancer Education and Support
(www.ustoo.com/Early_Detection.asp)
[1-6]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Prostate cancer. National Cancer Institute. Web site: http://cancernet.nci.nih.gov/cancertopics/types/prostate.
2. Screening for prostate cancer: recommendation and rationale. Ann Intern Med 2002; 137:915.
3. Smith, RA, von Eschenbach, AC, Wender, R, et al. American Cancer Society Guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. CA Cancer J Clin 2001; 51:38.
4. Prostate-specific antigen (PSA) best practice policy. American Urological Association (AUA). Oncology (Williston Park) 2000; 14:267.
5. Whittemore, AS, Cirillo, PM, Feldman, D, Cohn, BA. Prostate specific antigen levels in young adulthood predict prostate cancer risk: results from a cohort of Black and White Americans. J Urol 2005; 174:872.
6. Carter, HB. Prostate cancers in men with low PSA levels--must we find them?. N Engl J Med 2004; 350:2292.
This topic review is designed to discuss the advantages and disadvantages of prostate cancer screening. Men should talk with their healthcare provider to decide what is best in their individual situation.
WHAT IS PROSTATE CANCER? — Prostate cancer is a malignancy of the prostate, a small gland in men that is located below the bladder and above the rectum (show figure 1). The prostate produces seminal fluid that helps carry sperm during ejaculation.
According to the American Cancer Society, about 234,000 men in the United States will be diagnosed with prostate cancer in 2006, and over 27,000 will die from this disease. Prostate cancer is the second most commonly diagnosed malignancy after skin cancer.
Although many men are diagnosed with prostate cancer, most of them do not die from their cancer. While the lifetime risk of being diagnosed with prostate cancer is about 17 percent, only 3 percent of men die from the disease. Furthermore, autopsies show that 30 percent of men 50 years and older die with undiagnosed prostate cancer. This suggests that prostate cancer may grow so slowly that many men die of other causes before they even develop symptoms of prostate cancer.
RISK FACTORS
Age — All men are at risk for prostate cancer, but the risk greatly increases with older age. Doctors rarely find prostate cancer in men younger than 50 years old.
Ethnic background — Black men develop prostate cancer more often than white men. They also are more likely to die of prostate cancer than white men.
Family medical history — Men who have a first-degree relative (a father or brother) with prostate cancer are more likely to develop the disease.
Diet — A diet high in animal fat may increase a man's risk of prostate cancer.
PROSTATE CANCER SCREENING — Prostate cancer screening involves two tests: A physical test called a digital rectal exam (DRE) A blood test that measures prostate specific antigen (PSA).
Digital rectal examination — The DRE is performed by a healthcare provider in the office by inserting a gloved, lubricated finger into the rectum to feel for any lumps or irregularities in the prostate gland (show figure 2). DRE can detect some cancers that are missed by the PSA test. However, because it is not possible to reach all areas of the prostate, some tumors can go undetected using this screening method alone. Additionally, microscopic prostate cancers are impossible to detect by touch, no matter where they are located.
Prostate specific antigen — PSA is a protein produced by the prostate. The serum PSA test measures the amount of PSA in a sample of blood. Although many men with prostate cancer have an elevated PSA concentration (greater than 4.0 ng/mL), a high level does not necessarily mean there is a cancer. The most common cause for an elevated PSA is benign prostatic hyperplasia (BPH), a noncancerous enlargement of the prostate. Other benign causes include prostate infection (prostatitis) and trauma. Trauma may be caused by bicycle riding or sexual activity; thus, the PSA should not be measured for 48 hours after these activities.
Generally speaking, the higher the PSA, the greater the chance that a cancer is present. However, in some studies, over 20 percent of men with prostate cancer had a normal PSA (false-negative test), while up to 40 percent of men without cancer had an abnormal PSA (false-positive test). Overall, only 30 percent of men with abnormal values will have prostate cancer.
Thus, the PSA test is not 100 percent accurate. False-negative results can delay diagnosis until the cancer is more advanced and less likely to be curable. False-positive results, which are common, can cause anxiety and lead to further testing that is more expensive to perform and is uncomfortable for patients.
Refinements in PSA blood testing such as measuring PSA velocity (rate of change over time), PSA density (PSA per volume of prostate tissue), free (unbound) PSA, and complex (bound to protein) PSA are intended to increase the accuracy of PSA tests, but there is not general agreement about the additional benefits of these tests.
If the DRE or PSA test is positive — A positive DRE or PSA test is not a reason to panic; benign conditions are the most common causes for an abnormal test, particularly for PSA tests. On the other hand, a positive test should not be ignored. Other tests, like transrectal ultrasound and prostate biopsy, are needed to evaluate a positive DRE or PSA.
Transrectal ultrasound — Transrectal ultrasound can be done in an office, and no sedation or anesthesia is needed. A small probe, about the size of a finger, is inserted into the rectum, and uses sound waves that bounce off the prostate to create an echo. A computer translates these echoes into an image (called a sonogram) of the prostate. About 80 percent of cancers have an abnormal ultrasound image. Transrectal ultrasound can also help to guide a surgeon to biopsy any area that appears abnormal.
Prostate biopsy — Prostate biopsy is also performed without sedation or anesthesia. It is done by inserting a small device into the rectum that can take a small sample of any suspicious areas (found either with DRE or ultrasound). Tissue samples are also taken from the base, middle, and tip of each side of the prostate. Some men experience temporary, mild rectal bleeding or blood in the urine or semen after this procedure. Rarely, biopsy can cause heavy bleeding or infection.
Up to one in five men with a negative result on an initial biopsy may have cancer diagnosed after subsequent biopsies. In addition, prostate biopsy can detect clinically unimportant cancers that are unlikely to cause illness or death; subsequent treatment for these cancers can ultimately cause more harm than good.
Summary — No screening test for prostate cancer is perfect. Experts who favor it suggest that the best screening strategy combines DRE with PSA testing, followed by transrectal ultrasound-guided prostate biopsy if either test is positive.
PROS AND CONS OF SCREENING — There are a number of arguments for and against prostate cancer screening.
Arguments for screening — Experts in favor of prostate cancer screening cite the following arguments: Even though many men with prostate cancer have nonaggressive tumors and do not die of the disease, the cancer is so common that a substantial number of men die from the cancer every year and many more suffer from the complications of advanced disease. For men with an aggressive prostate cancer, the best chance for curing it is probably by finding it at an early stage through screening and then treating it with surgery or radiation. Studies have shown that men who have prostate cancer detected by PSA screening tend to have earlier-stage cancer than men who have a cancer detected by other means. (See "Patient information: Advanced prostate cancer" and see "Patient information: Treatment for early prostate cancer"). The five-year survival for men who have prostate cancer confined to the prostate gland (early stage) is nearly 100 percent; this drops to 30 percent for men whose cancer has spread to other areas of the body. Chemotherapy and radiation therapy are relatively ineffective once prostate cancer has spread outside the prostate gland. The available screening tests are not perfect, but they are fairly good compared with screening tests for some other cancers, and they are easy to perform. The death rate due to prostate cancer has declined in recent years. This may be due to increased screening or improvements in prostate cancer treatment, particularly for advanced cancers. The death rate may also have declined due to changes in the ways that physicians complete death certificates.
Arguments against screening — The main argument against screening is that it is not clear if screening and treatment help men live longer and/or avoid the complications of advanced prostate cancer. No well-performed studies have determined that prostate cancer screening in the general population saves lives. Studies are currently underway to answer this important question, but the results may not be available for some time.
Other arguments have also been made against screening: Because of the relatively high number of false-positive DRE and PSA tests, a number of screened men will undergo unnecessary further testing with transrectal ultrasound and prostate biopsy. These secondary tests are relatively safe to perform, but they are not totally without side effects, and they add further costs. The side effects of treatment for early prostate cancers that are detected with screening may be substantial. Surgery and radiation therapy are the most popular therapies, and both can cause erectile dysfunction, urinary incontinence, and bowel problems. Although there are some tools to predict which cancers are more aggressive than others, these tools are not always accurate.
Many prostate cancers detected with screening are unlikely to cause death or disability. Thus, a number of men will have to experience the side effects of surgery and radiation for cancers that would never have bothered them had they gone undetected. In other words, even if the screening process works and a cancer is detected, it is not clear in all cases that the treatment is more beneficial than harmful.
PREVENTION OF PROSTATE CANCER
Supplements — Studies suggest that vitamin E and selenium supplements may protect against prostate cancer, but there is not enough evidence to recommend these supplements to all men.
Medications — Finasteride (Proscar®) has been shown to reduce the risk of developing prostate cancer by about 25 percent. However, aggressive cancers were diagnosed more frequently during the first year in men treated with finasteride than in those taking a placebo (look-alike substitute that contains no medication) pill. The reasons for this finding are not clear. It is not clear if finasteride should be offered to men at high risk for prostate cancer.
RECOMMENDATIONS
Professional organizations — Major medical associations and societies have issued conflicting recommendations regarding screening, making it difficult for an individual to decide if screening is right. The United States Preventive Services Task Force [2] and many European cancer societies have not endorsed routine serum PSA screening for the early detection of prostate cancer, while the American Cancer Society [3] and American Urological Association [4] do recommend screening. With currently available data, it is not possible to determine if the benefits of screening outweigh the significant risks associated with treatment.
A number of studies are expected to be completed over the next several years that should help clarify this controversy. In the meantime, the American Cancer Society, American Urological Association, and American College of Physicians recommend that men have an open discussion with their clinician.
The best way to decide if prostate cancer screening is right is to: Consider individual prostate cancer risk factors Know the potential benefits and harms of screening, diagnosis, and treatment Talk to a clinician about concerns or questions.
For men who choose screening — If a man chooses to have screening, he should begin at age 50. Men with risk factors for prostate cancer (such as black men or a man with a father or brother who had prostate cancer) may want to begin screening at the age of 45.
Screening should continue yearly once it is started, though less frequent testing may be appropriate for some men with a low PSA. For men who choose screening, we suggest that those with a PSA level below 1.0 ng/mL consider having PSA testing every four years and that those with a higher PSA level consider having PSA testing annually. We suggest that men who choose screening have an annual digital rectal exam, regardless of their PSA level.
Screening not recommended — Screening should not be performed in men who are 75 years and older or who have serious health problems; these men are unlikely to live long enough to benefit from screening and/or treatment.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
1-800-4-CANCER
(www.cancer.gov/cancertopics/screening/prostate)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
National Comprehensive Cancer Network
(www.nccn.org/patients/patient_gls.asp)
American Cancer Society
1-800-ACS-2345
(www.cancer.org)
National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
US TOO! Prostate Cancer Education and Support
(www.ustoo.com/Early_Detection.asp)
[1-6]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Prostate cancer. National Cancer Institute. Web site: http://cancernet.nci.nih.gov/cancertopics/types/prostate.
2. Screening for prostate cancer: recommendation and rationale. Ann Intern Med 2002; 137:915.
3. Smith, RA, von Eschenbach, AC, Wender, R, et al. American Cancer Society Guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. CA Cancer J Clin 2001; 51:38.
4. Prostate-specific antigen (PSA) best practice policy. American Urological Association (AUA). Oncology (Williston Park) 2000; 14:267.
5. Whittemore, AS, Cirillo, PM, Feldman, D, Cohn, BA. Prostate specific antigen levels in young adulthood predict prostate cancer risk: results from a cohort of Black and White Americans. J Urol 2005; 174:872.
6. Carter, HB. Prostate cancers in men with low PSA levels--must we find them?. N Engl J Med 2004; 350:2292.
Lung cancer prevention and screening
INTRODUCTION — Lung cancer is the leading cause of cancer death in both men and women in the United States. The number of people dying from lung cancer each year has risen over the past 25 years. It is estimated that lung cancer will be responsible for approximately 160,000 deaths in the US during 2006. This is more than the estimated deaths from breast cancer, prostate cancer, and colorectal cancer combined. Several factors increase the risk of lung cancer, particularly cigarette smoking.
PREVENTING LUNG CANCER — Cigarette smoking is responsible for almost 90 percent of cases of lung cancer. Exposure to certain substances, such as asbestos, has also been linked to the development of lung cancer. Exposure to second-hand smoke and other environmental factors may play a role.
The best way to avoid getting lung cancer is not to smoke. Some smokers believe that once they have smoked for a long while, it does little good to quit. However, studies have shown that smokers who quit decrease their risk of lung cancer when compared to those who continue to smoke. Smokers who quit for more than 15 years have an 80 to 90 percent reduction in their risk of lung cancer compared to people who continue to smoke. (See "Patient information: Smoking cessation").
IS SCREENING WORTHWHILE? — Screening is a way to detect a disease in its earliest stages, before a person becomes ill or dies. To be recommended, it must be clear that screening is useful in identifying patients who have the disease in the early stages, and that this discovery can reduce the number of patients who become ill and/or die.
Some screening exams have proven to make a clear difference in patient outcomes. Examples are the Pap smear for detection of cervical cancer in women, and colonoscopy for detection of colon or rectal cancer in people over 50 years old. These exams are now part of routine health care in the United States.
SCREENING EXAMS FOR LUNG CANCER — Research studies have been done to determine if screening for lung cancer makes sense. In these studies, smokers (who are at highest risk to develop the disease) are divided into groups. Some groups have screening tests while others have no screening. The groups are then followed over many years. Data are gathered on how many patients in each group are diagnosed with lung cancer, how the cancer was treated, and how long patients with lung cancer survived after treatment.
So far, the data from these studies have not shown that screening for lung cancer makes a difference in deaths from the disease. For this reason, major medical advisory groups do not yet recommend lung cancer screening.
Still, the data from these studies are the subject of much debate in the medical community. Part of the debate surrounds the fact that outcomes other than overall mortality, such as the stage of the disease at diagnosis or five-year survival rate, seem to be favorably affected by screening. However, critics point out that data are difficult to interpret reliably. The debate is continuing, and more studies are underway to better understand the role of screening studies for lung cancer
Because of the lack of data on the efficacy of screening for lung cancer, most of these exams are not part of routine care and are only offered to smokers as part of ongoing clinical trials. One exception may be the annual chest x-ray.
Chest x-ray — Many doctors already recommend an annual chest x-ray for their patients who smoke. Some experts, in analyzing data from lung cancer screening trials, have concluded that an annual chest x-ray is a worthwhile screening exam for patients with lung cancer.
Two major studies have been done to find out whether more frequent chest x-rays are beneficial in lung cancer screening. So far, these studies have not shown a clear benefit in terms of deaths from lung cancer. In patients who had more frequent chest x-rays, more lung cancers at early stages were found, the cancers were more frequently removable by surgery, and the patients had longer five-year survival (from time of diagnosis) than patients with less frequent x-rays. However, overall mortality from lung cancer was not significantly affected.
Computed tomography (CT scan) — Studies of computed tomography (CT scan) of the lung have shown that the test can help detect early stage lung cancer, but it is not yet clear whether this will affect the number of patients who die from their cancer.
Sputum tests — Some studies have looked at the efficacy of analyzing a patient's sputum for evidence of cancer cells in order to detect lung cancer. So far, no clear benefit to this approach has been found. Additional studies that use new technologies to examine the sputum are underway.
PET scan — Researchers are looking at a number of other tools in an effort to help identify patients with lung cancer. Positron Emission Tomography (or PET scanning, which uses a small amount of radioactivity to provide a detailed picture of an organ's function) has been used in combination with CT scanning.
Other studies — Direct visualization of the lungs with bronchoscopy and breath analysis for cancer markers are two tests that may be used in future studies.
CLINICAL TRIALS — Because the data on lung cancer screening are inconclusive, large-scale clinical trials of various screening modalities are underway. Smokers or former smokers may be asked to participate in these trials.
Although it makes sense to think that early detection of lung cancer is a good idea, it is important to understand that routine screening for lung cancer cannot be recommended until the research clearly shows that it makes a difference. It is likely that recommendations on lung cancer screening will evolve over the next decades as these data become available.
SUMMARY Patients who smoke are at increased risk of developing lung cancer. The best way to avoid lung cancer is not to smoke. Even long-term smokers can benefit from quitting. Researchers are looking for ways to help smokers and non-smokers who develop lung cancer to live longer. Early detection and screening is a major focus of this effort It is not clear if lung cancer screening can reduce the number of people who die from their disease. Clinical trials are underway that will help provide answers to these questions.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
(www.cancernet.nci.nih.gov/)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
The American Cancer Society
(www.cancer.org)
Lung Cancer Alliance
(www.lungcanceralliance.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Jemal, A, Siegel, R, Ward, E, et al. Cancer statistics, 2006. CA Cancer J Clin 2007; 57:43.
2. Truong, MT, Munden, RF. Lung cancer screening. Curr Oncol Rep 2003; 5:309.
3. Nawa, T, Nakagawa, T, Kusano, S, et al. Lung cancer screening using low-dose spiral CT: results of baseline and 1-year follow-up studies. Chest 2002; 122:15.
4. Bastarrika, G, Garcia-Velloso, MJ, Lozano, MD, et al. Early Lung Cancer Detection using Spiral Computed Tomography and Positron Emission Tomography. Am J Respir Crit Care Med 2005; 171:1378.
PREVENTING LUNG CANCER — Cigarette smoking is responsible for almost 90 percent of cases of lung cancer. Exposure to certain substances, such as asbestos, has also been linked to the development of lung cancer. Exposure to second-hand smoke and other environmental factors may play a role.
The best way to avoid getting lung cancer is not to smoke. Some smokers believe that once they have smoked for a long while, it does little good to quit. However, studies have shown that smokers who quit decrease their risk of lung cancer when compared to those who continue to smoke. Smokers who quit for more than 15 years have an 80 to 90 percent reduction in their risk of lung cancer compared to people who continue to smoke. (See "Patient information: Smoking cessation").
IS SCREENING WORTHWHILE? — Screening is a way to detect a disease in its earliest stages, before a person becomes ill or dies. To be recommended, it must be clear that screening is useful in identifying patients who have the disease in the early stages, and that this discovery can reduce the number of patients who become ill and/or die.
Some screening exams have proven to make a clear difference in patient outcomes. Examples are the Pap smear for detection of cervical cancer in women, and colonoscopy for detection of colon or rectal cancer in people over 50 years old. These exams are now part of routine health care in the United States.
SCREENING EXAMS FOR LUNG CANCER — Research studies have been done to determine if screening for lung cancer makes sense. In these studies, smokers (who are at highest risk to develop the disease) are divided into groups. Some groups have screening tests while others have no screening. The groups are then followed over many years. Data are gathered on how many patients in each group are diagnosed with lung cancer, how the cancer was treated, and how long patients with lung cancer survived after treatment.
So far, the data from these studies have not shown that screening for lung cancer makes a difference in deaths from the disease. For this reason, major medical advisory groups do not yet recommend lung cancer screening.
Still, the data from these studies are the subject of much debate in the medical community. Part of the debate surrounds the fact that outcomes other than overall mortality, such as the stage of the disease at diagnosis or five-year survival rate, seem to be favorably affected by screening. However, critics point out that data are difficult to interpret reliably. The debate is continuing, and more studies are underway to better understand the role of screening studies for lung cancer
Because of the lack of data on the efficacy of screening for lung cancer, most of these exams are not part of routine care and are only offered to smokers as part of ongoing clinical trials. One exception may be the annual chest x-ray.
Chest x-ray — Many doctors already recommend an annual chest x-ray for their patients who smoke. Some experts, in analyzing data from lung cancer screening trials, have concluded that an annual chest x-ray is a worthwhile screening exam for patients with lung cancer.
Two major studies have been done to find out whether more frequent chest x-rays are beneficial in lung cancer screening. So far, these studies have not shown a clear benefit in terms of deaths from lung cancer. In patients who had more frequent chest x-rays, more lung cancers at early stages were found, the cancers were more frequently removable by surgery, and the patients had longer five-year survival (from time of diagnosis) than patients with less frequent x-rays. However, overall mortality from lung cancer was not significantly affected.
Computed tomography (CT scan) — Studies of computed tomography (CT scan) of the lung have shown that the test can help detect early stage lung cancer, but it is not yet clear whether this will affect the number of patients who die from their cancer.
Sputum tests — Some studies have looked at the efficacy of analyzing a patient's sputum for evidence of cancer cells in order to detect lung cancer. So far, no clear benefit to this approach has been found. Additional studies that use new technologies to examine the sputum are underway.
PET scan — Researchers are looking at a number of other tools in an effort to help identify patients with lung cancer. Positron Emission Tomography (or PET scanning, which uses a small amount of radioactivity to provide a detailed picture of an organ's function) has been used in combination with CT scanning.
Other studies — Direct visualization of the lungs with bronchoscopy and breath analysis for cancer markers are two tests that may be used in future studies.
CLINICAL TRIALS — Because the data on lung cancer screening are inconclusive, large-scale clinical trials of various screening modalities are underway. Smokers or former smokers may be asked to participate in these trials.
Although it makes sense to think that early detection of lung cancer is a good idea, it is important to understand that routine screening for lung cancer cannot be recommended until the research clearly shows that it makes a difference. It is likely that recommendations on lung cancer screening will evolve over the next decades as these data become available.
SUMMARY Patients who smoke are at increased risk of developing lung cancer. The best way to avoid lung cancer is not to smoke. Even long-term smokers can benefit from quitting. Researchers are looking for ways to help smokers and non-smokers who develop lung cancer to live longer. Early detection and screening is a major focus of this effort It is not clear if lung cancer screening can reduce the number of people who die from their disease. Clinical trials are underway that will help provide answers to these questions.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
(www.cancernet.nci.nih.gov/)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
The American Cancer Society
(www.cancer.org)
Lung Cancer Alliance
(www.lungcanceralliance.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Jemal, A, Siegel, R, Ward, E, et al. Cancer statistics, 2006. CA Cancer J Clin 2007; 57:43.
2. Truong, MT, Munden, RF. Lung cancer screening. Curr Oncol Rep 2003; 5:309.
3. Nawa, T, Nakagawa, T, Kusano, S, et al. Lung cancer screening using low-dose spiral CT: results of baseline and 1-year follow-up studies. Chest 2002; 122:15.
4. Bastarrika, G, Garcia-Velloso, MJ, Lozano, MD, et al. Early Lung Cancer Detection using Spiral Computed Tomography and Positron Emission Tomography. Am J Respir Crit Care Med 2005; 171:1378.
Lung cancer prevention and screening
INTRODUCTION — Lung cancer is the leading cause of cancer death in both men and women in the United States. The number of people dying from lung cancer each year has risen over the past 25 years. It is estimated that lung cancer will be responsible for approximately 160,000 deaths in the US during 2006. This is more than the estimated deaths from breast cancer, prostate cancer, and colorectal cancer combined. Several factors increase the risk of lung cancer, particularly cigarette smoking.
PREVENTING LUNG CANCER — Cigarette smoking is responsible for almost 90 percent of cases of lung cancer. Exposure to certain substances, such as asbestos, has also been linked to the development of lung cancer. Exposure to second-hand smoke and other environmental factors may play a role.
The best way to avoid getting lung cancer is not to smoke. Some smokers believe that once they have smoked for a long while, it does little good to quit. However, studies have shown that smokers who quit decrease their risk of lung cancer when compared to those who continue to smoke. Smokers who quit for more than 15 years have an 80 to 90 percent reduction in their risk of lung cancer compared to people who continue to smoke. (See "Patient information: Smoking cessation").
IS SCREENING WORTHWHILE? — Screening is a way to detect a disease in its earliest stages, before a person becomes ill or dies. To be recommended, it must be clear that screening is useful in identifying patients who have the disease in the early stages, and that this discovery can reduce the number of patients who become ill and/or die.
Some screening exams have proven to make a clear difference in patient outcomes. Examples are the Pap smear for detection of cervical cancer in women, and colonoscopy for detection of colon or rectal cancer in people over 50 years old. These exams are now part of routine health care in the United States.
SCREENING EXAMS FOR LUNG CANCER — Research studies have been done to determine if screening for lung cancer makes sense. In these studies, smokers (who are at highest risk to develop the disease) are divided into groups. Some groups have screening tests while others have no screening. The groups are then followed over many years. Data are gathered on how many patients in each group are diagnosed with lung cancer, how the cancer was treated, and how long patients with lung cancer survived after treatment.
So far, the data from these studies have not shown that screening for lung cancer makes a difference in deaths from the disease. For this reason, major medical advisory groups do not yet recommend lung cancer screening.
Still, the data from these studies are the subject of much debate in the medical community. Part of the debate surrounds the fact that outcomes other than overall mortality, such as the stage of the disease at diagnosis or five-year survival rate, seem to be favorably affected by screening. However, critics point out that data are difficult to interpret reliably. The debate is continuing, and more studies are underway to better understand the role of screening studies for lung cancer
Because of the lack of data on the efficacy of screening for lung cancer, most of these exams are not part of routine care and are only offered to smokers as part of ongoing clinical trials. One exception may be the annual chest x-ray.
Chest x-ray — Many doctors already recommend an annual chest x-ray for their patients who smoke. Some experts, in analyzing data from lung cancer screening trials, have concluded that an annual chest x-ray is a worthwhile screening exam for patients with lung cancer.
Two major studies have been done to find out whether more frequent chest x-rays are beneficial in lung cancer screening. So far, these studies have not shown a clear benefit in terms of deaths from lung cancer. In patients who had more frequent chest x-rays, more lung cancers at early stages were found, the cancers were more frequently removable by surgery, and the patients had longer five-year survival (from time of diagnosis) than patients with less frequent x-rays. However, overall mortality from lung cancer was not significantly affected.
Computed tomography (CT scan) — Studies of computed tomography (CT scan) of the lung have shown that the test can help detect early stage lung cancer, but it is not yet clear whether this will affect the number of patients who die from their cancer.
Sputum tests — Some studies have looked at the efficacy of analyzing a patient's sputum for evidence of cancer cells in order to detect lung cancer. So far, no clear benefit to this approach has been found. Additional studies that use new technologies to examine the sputum are underway.
PET scan — Researchers are looking at a number of other tools in an effort to help identify patients with lung cancer. Positron Emission Tomography (or PET scanning, which uses a small amount of radioactivity to provide a detailed picture of an organ's function) has been used in combination with CT scanning.
Other studies — Direct visualization of the lungs with bronchoscopy and breath analysis for cancer markers are two tests that may be used in future studies.
CLINICAL TRIALS — Because the data on lung cancer screening are inconclusive, large-scale clinical trials of various screening modalities are underway. Smokers or former smokers may be asked to participate in these trials.
Although it makes sense to think that early detection of lung cancer is a good idea, it is important to understand that routine screening for lung cancer cannot be recommended until the research clearly shows that it makes a difference. It is likely that recommendations on lung cancer screening will evolve over the next decades as these data become available.
SUMMARY Patients who smoke are at increased risk of developing lung cancer. The best way to avoid lung cancer is not to smoke. Even long-term smokers can benefit from quitting. Researchers are looking for ways to help smokers and non-smokers who develop lung cancer to live longer. Early detection and screening is a major focus of this effort It is not clear if lung cancer screening can reduce the number of people who die from their disease. Clinical trials are underway that will help provide answers to these questions.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
(www.cancernet.nci.nih.gov/)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
The American Cancer Society
(www.cancer.org)
Lung Cancer Alliance
(www.lungcanceralliance.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Jemal, A, Siegel, R, Ward, E, et al. Cancer statistics, 2006. CA Cancer J Clin 2007; 57:43.
2. Truong, MT, Munden, RF. Lung cancer screening. Curr Oncol Rep 2003; 5:309.
3. Nawa, T, Nakagawa, T, Kusano, S, et al. Lung cancer screening using low-dose spiral CT: results of baseline and 1-year follow-up studies. Chest 2002; 122:15.
4. Bastarrika, G, Garcia-Velloso, MJ, Lozano, MD, et al. Early Lung Cancer Detection using Spiral Computed Tomography and Positron Emission Tomography. Am J Respir Crit Care Med 2005; 171:1378.
PREVENTING LUNG CANCER — Cigarette smoking is responsible for almost 90 percent of cases of lung cancer. Exposure to certain substances, such as asbestos, has also been linked to the development of lung cancer. Exposure to second-hand smoke and other environmental factors may play a role.
The best way to avoid getting lung cancer is not to smoke. Some smokers believe that once they have smoked for a long while, it does little good to quit. However, studies have shown that smokers who quit decrease their risk of lung cancer when compared to those who continue to smoke. Smokers who quit for more than 15 years have an 80 to 90 percent reduction in their risk of lung cancer compared to people who continue to smoke. (See "Patient information: Smoking cessation").
IS SCREENING WORTHWHILE? — Screening is a way to detect a disease in its earliest stages, before a person becomes ill or dies. To be recommended, it must be clear that screening is useful in identifying patients who have the disease in the early stages, and that this discovery can reduce the number of patients who become ill and/or die.
Some screening exams have proven to make a clear difference in patient outcomes. Examples are the Pap smear for detection of cervical cancer in women, and colonoscopy for detection of colon or rectal cancer in people over 50 years old. These exams are now part of routine health care in the United States.
SCREENING EXAMS FOR LUNG CANCER — Research studies have been done to determine if screening for lung cancer makes sense. In these studies, smokers (who are at highest risk to develop the disease) are divided into groups. Some groups have screening tests while others have no screening. The groups are then followed over many years. Data are gathered on how many patients in each group are diagnosed with lung cancer, how the cancer was treated, and how long patients with lung cancer survived after treatment.
So far, the data from these studies have not shown that screening for lung cancer makes a difference in deaths from the disease. For this reason, major medical advisory groups do not yet recommend lung cancer screening.
Still, the data from these studies are the subject of much debate in the medical community. Part of the debate surrounds the fact that outcomes other than overall mortality, such as the stage of the disease at diagnosis or five-year survival rate, seem to be favorably affected by screening. However, critics point out that data are difficult to interpret reliably. The debate is continuing, and more studies are underway to better understand the role of screening studies for lung cancer
Because of the lack of data on the efficacy of screening for lung cancer, most of these exams are not part of routine care and are only offered to smokers as part of ongoing clinical trials. One exception may be the annual chest x-ray.
Chest x-ray — Many doctors already recommend an annual chest x-ray for their patients who smoke. Some experts, in analyzing data from lung cancer screening trials, have concluded that an annual chest x-ray is a worthwhile screening exam for patients with lung cancer.
Two major studies have been done to find out whether more frequent chest x-rays are beneficial in lung cancer screening. So far, these studies have not shown a clear benefit in terms of deaths from lung cancer. In patients who had more frequent chest x-rays, more lung cancers at early stages were found, the cancers were more frequently removable by surgery, and the patients had longer five-year survival (from time of diagnosis) than patients with less frequent x-rays. However, overall mortality from lung cancer was not significantly affected.
Computed tomography (CT scan) — Studies of computed tomography (CT scan) of the lung have shown that the test can help detect early stage lung cancer, but it is not yet clear whether this will affect the number of patients who die from their cancer.
Sputum tests — Some studies have looked at the efficacy of analyzing a patient's sputum for evidence of cancer cells in order to detect lung cancer. So far, no clear benefit to this approach has been found. Additional studies that use new technologies to examine the sputum are underway.
PET scan — Researchers are looking at a number of other tools in an effort to help identify patients with lung cancer. Positron Emission Tomography (or PET scanning, which uses a small amount of radioactivity to provide a detailed picture of an organ's function) has been used in combination with CT scanning.
Other studies — Direct visualization of the lungs with bronchoscopy and breath analysis for cancer markers are two tests that may be used in future studies.
CLINICAL TRIALS — Because the data on lung cancer screening are inconclusive, large-scale clinical trials of various screening modalities are underway. Smokers or former smokers may be asked to participate in these trials.
Although it makes sense to think that early detection of lung cancer is a good idea, it is important to understand that routine screening for lung cancer cannot be recommended until the research clearly shows that it makes a difference. It is likely that recommendations on lung cancer screening will evolve over the next decades as these data become available.
SUMMARY Patients who smoke are at increased risk of developing lung cancer. The best way to avoid lung cancer is not to smoke. Even long-term smokers can benefit from quitting. Researchers are looking for ways to help smokers and non-smokers who develop lung cancer to live longer. Early detection and screening is a major focus of this effort It is not clear if lung cancer screening can reduce the number of people who die from their disease. Clinical trials are underway that will help provide answers to these questions.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Cancer Institute
(www.cancernet.nci.nih.gov/)
People Living With Cancer: The official patient information
website of the American Society of Clinical Oncology
(www.plwc.org/portal/site/PLWC)
The American Cancer Society
(www.cancer.org)
Lung Cancer Alliance
(www.lungcanceralliance.org)
[1-4]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Jemal, A, Siegel, R, Ward, E, et al. Cancer statistics, 2006. CA Cancer J Clin 2007; 57:43.
2. Truong, MT, Munden, RF. Lung cancer screening. Curr Oncol Rep 2003; 5:309.
3. Nawa, T, Nakagawa, T, Kusano, S, et al. Lung cancer screening using low-dose spiral CT: results of baseline and 1-year follow-up studies. Chest 2002; 122:15.
4. Bastarrika, G, Garcia-Velloso, MJ, Lozano, MD, et al. Early Lung Cancer Detection using Spiral Computed Tomography and Positron Emission Tomography. Am J Respir Crit Care Med 2005; 171:1378.
Flexible sigmoidoscopy
INTRODUCTION — A flexible sigmoidoscopy is an examination of the lower (distal) part of the gastrointestinal tract, called the colon or large intestine (show figure 1). It is performed by an endoscopist, a doctor or other health professional with special training in endoscopic procedures. There are several reasons that flexible signmoidoscopy may be recommended, with one of the most common reasons being the need to screen for colon cancer in people older than 50 years.
Colonoscopy allows the physician to examine the entire large intestine, and is preferred over flexible sigmoidoscopy if the entire colon needs to be examined. (See "Patient information: Colonoscopy").
REASONS FOR FLEXIBLE SIGMOIDOSCOPY — The most common reasons for flexible sigmoidoscopy are the following: As a screening test to detect colon polyps or colon cancer in people over age fifty Blood in the stool or rectal bleeding (sigmoidoscopy may be recommended to evaluate bleeding) Persistent diarrhea After radiation treatment to the pelvis when a patient has lower gastrointestinal symptoms Evaluation of the colon in conjunction with a barium enema For the medical management of colitis (inflammation of the colon)
PREPARATION — Your doctor will provide you with specific Instructions on how to prepare for the examination. The instructions are designed to maximize your safety during and after the examination, minimize possible complications, and provide the endoscopist with the best look at your colon.
It is important for you to read the instructions ahead of time and follow them carefully. Call your doctor or the endoscopy unit if you have questions.
Bowel cleaning — The lower part of the colon must be cleaned to permit the endoscopist to see the inside lining of the colon. Specific instruction will be provided, although preparation usually involves consuming a clear liquid diet, laxatives, and use of an enemas shortly before the examination.
Medications — Some medications, such as aspirin products and iron preparations, should be stopped one to two weeks before the examination. Aspirin increases the risk of bleeding after the test, while iron coats the colon, making it difficult to see the lining. People who take a blood thinning medication such as warfarin (Coumadin®) should consult with their clinician regarding the need to stop taking this medication temporarily.
Most medications for high blood pressure, heart disease, lung disease, and seizure disorders are safe during sigmoidoscopy and can be taken the day of the examination.
Medications for diabetes may need to be decreased before the test; patients should talk with their diabetes clinician.
WHAT TO EXPECT — Prior to the sigmoidoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned A doctor will review the procedure, including possible complications, and will ask the patient to sign a consent form.
The procedure — Flexible sigmoidoscopy usually takes between five and fifteen minutes. It is performed while the patient lies on their left side with the legs curled up against the chest. The sigmoidoscope, which is approximately the size of one finger, is inserted into the anus and advanced through the rectum, sigmoid colon, and descending colon. The sigmoidoscope has a lens and a light source that permits the endoscopist to look into the scope or at a television monitor.
The endoscope allows the endoscopist to take biopsies (small pieces of tissue) and to introduce or withdraw fluid or air. Biopsies do not hurt because the lining of the colon does not sense pain. However, some patients will feel cramping as air is introduced through the scope and as the scope is passed through segments of the colon. The air is needed to permit the endoscopist to advance the scope and see the lining of the colon. It is common to feel embarrassed about releasing air through their rectum, although this is recommended to decrease discomfort. Let the endoscopist know if there is discomfort since air can also be removed through the scope. Because the procedure is brief and discomfort is mild, pain medications or sedation are not routinely used.
COMPLICATIONS — Flexible sigmoidoscopy is a safe procedure and complications are rare. Bleeding can occur from biopsies or the removal of polyps, but this is usually minimal and stops quickly or can be controlled. The scope can cause a tear or hole in the tissue being examined. This is a serious problem that does not occur commonly.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons
AFTER FLEXIBLE SIGMOIDOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Most patients are able to return to normal activities, including eating, after the examination
Patients should contact their doctor about the results of the test and if there are any questions. The endoscopy team will let the patient know when all the results will be available and if further treatment is necessary.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy:
(www.askasge.org)
National Digestive Disease Information Clearinghouse
(http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm)
[1-3]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Doria-Rose, VP, Levin, TR, Selby, JV, et al. The incidence of colorectal cancer following a negative screening sigmoidoscopy: Implications for screening interval. Gastroenterology 2004; 127:714.
2. Fletcher, RH. Screening sigmoidoscopy-- how often and how good?. JAMA 2003; 290:106.
3. Levin, TR, Conell, C, Shapiro, JA, et al. Complications of screening flexible sigmoidoscopy. Gastroenterology 2002; 123:1786.
Colonoscopy allows the physician to examine the entire large intestine, and is preferred over flexible sigmoidoscopy if the entire colon needs to be examined. (See "Patient information: Colonoscopy").
REASONS FOR FLEXIBLE SIGMOIDOSCOPY — The most common reasons for flexible sigmoidoscopy are the following: As a screening test to detect colon polyps or colon cancer in people over age fifty Blood in the stool or rectal bleeding (sigmoidoscopy may be recommended to evaluate bleeding) Persistent diarrhea After radiation treatment to the pelvis when a patient has lower gastrointestinal symptoms Evaluation of the colon in conjunction with a barium enema For the medical management of colitis (inflammation of the colon)
PREPARATION — Your doctor will provide you with specific Instructions on how to prepare for the examination. The instructions are designed to maximize your safety during and after the examination, minimize possible complications, and provide the endoscopist with the best look at your colon.
It is important for you to read the instructions ahead of time and follow them carefully. Call your doctor or the endoscopy unit if you have questions.
Bowel cleaning — The lower part of the colon must be cleaned to permit the endoscopist to see the inside lining of the colon. Specific instruction will be provided, although preparation usually involves consuming a clear liquid diet, laxatives, and use of an enemas shortly before the examination.
Medications — Some medications, such as aspirin products and iron preparations, should be stopped one to two weeks before the examination. Aspirin increases the risk of bleeding after the test, while iron coats the colon, making it difficult to see the lining. People who take a blood thinning medication such as warfarin (Coumadin®) should consult with their clinician regarding the need to stop taking this medication temporarily.
Most medications for high blood pressure, heart disease, lung disease, and seizure disorders are safe during sigmoidoscopy and can be taken the day of the examination.
Medications for diabetes may need to be decreased before the test; patients should talk with their diabetes clinician.
WHAT TO EXPECT — Prior to the sigmoidoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned A doctor will review the procedure, including possible complications, and will ask the patient to sign a consent form.
The procedure — Flexible sigmoidoscopy usually takes between five and fifteen minutes. It is performed while the patient lies on their left side with the legs curled up against the chest. The sigmoidoscope, which is approximately the size of one finger, is inserted into the anus and advanced through the rectum, sigmoid colon, and descending colon. The sigmoidoscope has a lens and a light source that permits the endoscopist to look into the scope or at a television monitor.
The endoscope allows the endoscopist to take biopsies (small pieces of tissue) and to introduce or withdraw fluid or air. Biopsies do not hurt because the lining of the colon does not sense pain. However, some patients will feel cramping as air is introduced through the scope and as the scope is passed through segments of the colon. The air is needed to permit the endoscopist to advance the scope and see the lining of the colon. It is common to feel embarrassed about releasing air through their rectum, although this is recommended to decrease discomfort. Let the endoscopist know if there is discomfort since air can also be removed through the scope. Because the procedure is brief and discomfort is mild, pain medications or sedation are not routinely used.
COMPLICATIONS — Flexible sigmoidoscopy is a safe procedure and complications are rare. Bleeding can occur from biopsies or the removal of polyps, but this is usually minimal and stops quickly or can be controlled. The scope can cause a tear or hole in the tissue being examined. This is a serious problem that does not occur commonly.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons
AFTER FLEXIBLE SIGMOIDOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Most patients are able to return to normal activities, including eating, after the examination
Patients should contact their doctor about the results of the test and if there are any questions. The endoscopy team will let the patient know when all the results will be available and if further treatment is necessary.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy:
(www.askasge.org)
National Digestive Disease Information Clearinghouse
(http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm)
[1-3]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Doria-Rose, VP, Levin, TR, Selby, JV, et al. The incidence of colorectal cancer following a negative screening sigmoidoscopy: Implications for screening interval. Gastroenterology 2004; 127:714.
2. Fletcher, RH. Screening sigmoidoscopy-- how often and how good?. JAMA 2003; 290:106.
3. Levin, TR, Conell, C, Shapiro, JA, et al. Complications of screening flexible sigmoidoscopy. Gastroenterology 2002; 123:1786.
Flexible sigmoidoscopy
INTRODUCTION — A flexible sigmoidoscopy is an examination of the lower (distal) part of the gastrointestinal tract, called the colon or large intestine (show figure 1). It is performed by an endoscopist, a doctor or other health professional with special training in endoscopic procedures. There are several reasons that flexible signmoidoscopy may be recommended, with one of the most common reasons being the need to screen for colon cancer in people older than 50 years.
Colonoscopy allows the physician to examine the entire large intestine, and is preferred over flexible sigmoidoscopy if the entire colon needs to be examined. (See "Patient information: Colonoscopy").
REASONS FOR FLEXIBLE SIGMOIDOSCOPY — The most common reasons for flexible sigmoidoscopy are the following: As a screening test to detect colon polyps or colon cancer in people over age fifty Blood in the stool or rectal bleeding (sigmoidoscopy may be recommended to evaluate bleeding) Persistent diarrhea After radiation treatment to the pelvis when a patient has lower gastrointestinal symptoms Evaluation of the colon in conjunction with a barium enema For the medical management of colitis (inflammation of the colon)
PREPARATION — Your doctor will provide you with specific Instructions on how to prepare for the examination. The instructions are designed to maximize your safety during and after the examination, minimize possible complications, and provide the endoscopist with the best look at your colon.
It is important for you to read the instructions ahead of time and follow them carefully. Call your doctor or the endoscopy unit if you have questions.
Bowel cleaning — The lower part of the colon must be cleaned to permit the endoscopist to see the inside lining of the colon. Specific instruction will be provided, although preparation usually involves consuming a clear liquid diet, laxatives, and use of an enemas shortly before the examination.
Medications — Some medications, such as aspirin products and iron preparations, should be stopped one to two weeks before the examination. Aspirin increases the risk of bleeding after the test, while iron coats the colon, making it difficult to see the lining. People who take a blood thinning medication such as warfarin (Coumadin®) should consult with their clinician regarding the need to stop taking this medication temporarily.
Most medications for high blood pressure, heart disease, lung disease, and seizure disorders are safe during sigmoidoscopy and can be taken the day of the examination.
Medications for diabetes may need to be decreased before the test; patients should talk with their diabetes clinician.
WHAT TO EXPECT — Prior to the sigmoidoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned A doctor will review the procedure, including possible complications, and will ask the patient to sign a consent form.
The procedure — Flexible sigmoidoscopy usually takes between five and fifteen minutes. It is performed while the patient lies on their left side with the legs curled up against the chest. The sigmoidoscope, which is approximately the size of one finger, is inserted into the anus and advanced through the rectum, sigmoid colon, and descending colon. The sigmoidoscope has a lens and a light source that permits the endoscopist to look into the scope or at a television monitor.
The endoscope allows the endoscopist to take biopsies (small pieces of tissue) and to introduce or withdraw fluid or air. Biopsies do not hurt because the lining of the colon does not sense pain. However, some patients will feel cramping as air is introduced through the scope and as the scope is passed through segments of the colon. The air is needed to permit the endoscopist to advance the scope and see the lining of the colon. It is common to feel embarrassed about releasing air through their rectum, although this is recommended to decrease discomfort. Let the endoscopist know if there is discomfort since air can also be removed through the scope. Because the procedure is brief and discomfort is mild, pain medications or sedation are not routinely used.
COMPLICATIONS — Flexible sigmoidoscopy is a safe procedure and complications are rare. Bleeding can occur from biopsies or the removal of polyps, but this is usually minimal and stops quickly or can be controlled. The scope can cause a tear or hole in the tissue being examined. This is a serious problem that does not occur commonly.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons
AFTER FLEXIBLE SIGMOIDOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Most patients are able to return to normal activities, including eating, after the examination
Patients should contact their doctor about the results of the test and if there are any questions. The endoscopy team will let the patient know when all the results will be available and if further treatment is necessary.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy:
(www.askasge.org)
National Digestive Disease Information Clearinghouse
(http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm)
[1-3]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Doria-Rose, VP, Levin, TR, Selby, JV, et al. The incidence of colorectal cancer following a negative screening sigmoidoscopy: Implications for screening interval. Gastroenterology 2004; 127:714.
2. Fletcher, RH. Screening sigmoidoscopy-- how often and how good?. JAMA 2003; 290:106.
3. Levin, TR, Conell, C, Shapiro, JA, et al. Complications of screening flexible sigmoidoscopy. Gastroenterology 2002; 123:1786.
Colonoscopy allows the physician to examine the entire large intestine, and is preferred over flexible sigmoidoscopy if the entire colon needs to be examined. (See "Patient information: Colonoscopy").
REASONS FOR FLEXIBLE SIGMOIDOSCOPY — The most common reasons for flexible sigmoidoscopy are the following: As a screening test to detect colon polyps or colon cancer in people over age fifty Blood in the stool or rectal bleeding (sigmoidoscopy may be recommended to evaluate bleeding) Persistent diarrhea After radiation treatment to the pelvis when a patient has lower gastrointestinal symptoms Evaluation of the colon in conjunction with a barium enema For the medical management of colitis (inflammation of the colon)
PREPARATION — Your doctor will provide you with specific Instructions on how to prepare for the examination. The instructions are designed to maximize your safety during and after the examination, minimize possible complications, and provide the endoscopist with the best look at your colon.
It is important for you to read the instructions ahead of time and follow them carefully. Call your doctor or the endoscopy unit if you have questions.
Bowel cleaning — The lower part of the colon must be cleaned to permit the endoscopist to see the inside lining of the colon. Specific instruction will be provided, although preparation usually involves consuming a clear liquid diet, laxatives, and use of an enemas shortly before the examination.
Medications — Some medications, such as aspirin products and iron preparations, should be stopped one to two weeks before the examination. Aspirin increases the risk of bleeding after the test, while iron coats the colon, making it difficult to see the lining. People who take a blood thinning medication such as warfarin (Coumadin®) should consult with their clinician regarding the need to stop taking this medication temporarily.
Most medications for high blood pressure, heart disease, lung disease, and seizure disorders are safe during sigmoidoscopy and can be taken the day of the examination.
Medications for diabetes may need to be decreased before the test; patients should talk with their diabetes clinician.
WHAT TO EXPECT — Prior to the sigmoidoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned A doctor will review the procedure, including possible complications, and will ask the patient to sign a consent form.
The procedure — Flexible sigmoidoscopy usually takes between five and fifteen minutes. It is performed while the patient lies on their left side with the legs curled up against the chest. The sigmoidoscope, which is approximately the size of one finger, is inserted into the anus and advanced through the rectum, sigmoid colon, and descending colon. The sigmoidoscope has a lens and a light source that permits the endoscopist to look into the scope or at a television monitor.
The endoscope allows the endoscopist to take biopsies (small pieces of tissue) and to introduce or withdraw fluid or air. Biopsies do not hurt because the lining of the colon does not sense pain. However, some patients will feel cramping as air is introduced through the scope and as the scope is passed through segments of the colon. The air is needed to permit the endoscopist to advance the scope and see the lining of the colon. It is common to feel embarrassed about releasing air through their rectum, although this is recommended to decrease discomfort. Let the endoscopist know if there is discomfort since air can also be removed through the scope. Because the procedure is brief and discomfort is mild, pain medications or sedation are not routinely used.
COMPLICATIONS — Flexible sigmoidoscopy is a safe procedure and complications are rare. Bleeding can occur from biopsies or the removal of polyps, but this is usually minimal and stops quickly or can be controlled. The scope can cause a tear or hole in the tissue being examined. This is a serious problem that does not occur commonly.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons
AFTER FLEXIBLE SIGMOIDOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Most patients are able to return to normal activities, including eating, after the examination
Patients should contact their doctor about the results of the test and if there are any questions. The endoscopy team will let the patient know when all the results will be available and if further treatment is necessary.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy:
(www.askasge.org)
National Digestive Disease Information Clearinghouse
(http://digestive.niddk.nih.gov/ddiseases/pubs/sigmoidoscopy/index.htm)
[1-3]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Doria-Rose, VP, Levin, TR, Selby, JV, et al. The incidence of colorectal cancer following a negative screening sigmoidoscopy: Implications for screening interval. Gastroenterology 2004; 127:714.
2. Fletcher, RH. Screening sigmoidoscopy-- how often and how good?. JAMA 2003; 290:106.
3. Levin, TR, Conell, C, Shapiro, JA, et al. Complications of screening flexible sigmoidoscopy. Gastroenterology 2002; 123:1786.
Colonoscopy
INTRODUCTION — Patients who require colonoscopy may have some questions and concerns about the procedure. This handout will provide information about colonoscopy and answers to questions that patients often ask.
Colonoscopy is a safe procedure that provides information other tests may not be able to give. A colonoscopy is an examination of the lower part of the gastrointestinal tract, which is called the colon or large intestine (bowel). It is performed by an endoscopist, a physician with special training in endoscopy procedures. The colonoscope is inserted into the anus and advanced through the entire colon (to the cecum) and possibly a short distance into the small intestine. The procedure generally between twenty minutes and one hour.
REASONS FOR COLONOSCOPY — The most common reasons for colonoscopy are to evaluate the following: As a screening exam for anyone over age 50 Blood in the stool or rectal bleeding Dark/black stools Persistent diarrhea Iron deficiency anemia (a decrease in blood count due to loss of iron) Significant, unexplained weight loss, accompanied by gastrointestinal symptoms A family history of colon cancer To follow up an abnormal barium enema A history of previous colon polyps or colon cancer Surveillance in people with ulcerative colitis For the medical management of chronic inflammatory bowel disease Chronic, unexplained abdominal pain.
PREPARATION — The endoscopy unit will provide specific instructions about how to prepare for the examination. The instructions are designed to maximize safety during and after the examination, minimize possible complications, and allow the endoscopist to fully view the colon.
It is important to read the instructions ahead of time and follow them carefully; patients who have questions should speak with their healthcare provider or the endoscopy unit.
The inside lining of the colon must be cleaned of stool to permit the endoscopist to complete a thorough examination. This is accomplished by restricting what is eaten and by using purgatives. What to eat — As a general rule, patients should not eat any solid food for at least one day before the examination. Only clear liquids (such as juices without pulp, bouillon, ginger ale) or clear gelatin (flavored is fine, but without added fruit) are recommended. The doctor's office or endoscopy unit will supply a list of fluids that are allowed. Purgatives — There are two methods commonly used to empty the bowel of stool. The first involves drinking a gallon of an undigestible solution (Go-Lytely®, and others) that causes temporary diarrhea. It comes in several flavors, which, unfortunately, only partially mask a somewhat unpleasant taste. Refrigerating the solution may make it more palatable. Drinking such a large volume of cold solution may cause a patient to feel chilled, but the sensation is temporary. Do not add flavoring to the solution. Many patients say that drinking the purgative solution is the most unpleasant part of the examination.
The second method involves drinking a solution called Fleets® Phosphosoda, along with several cups of liquid. This preparation is easier to consume than the purgative described above. However, the solution contains a large amount of phosphorus, which may be a problem for people with heart or kidney conditions. Medications — Some medications, such as aspirin and iron preparations, should be discontinued for one to two weeks before the examination. Aspirin and pain killers such as Motrin (which contains ibuprofen) slightly increase the risk of bleeding. Patients who take a blood thinning medication should consult with their doctor as to when they should stop taking it. Patients should also ask about medications for diabetes, heart or lung disease, high blood pressure, or seizure disorders. Some medications should not be stopped, and many of them can be taken the examination. Patients who take antibiotics before dental procedures should ask if they will be needed before colonoscopy. Transportation home — Patients need to arrange for someone to escort them safely home after the examination. Although patients will be awake by the time of discharge, the sedative medications cause changes in reflexes and judgment that cause a person to feel well but can interfere with the ability to make decisions, similar to the effect of alcohol.
WHAT TO EXPECT — Prior to the endoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned. The nurse will ask questions to ensure the patient has prepared properly for the procedure. A doctor will also review the procedure, including possible complications, and will ask patients to sign a consent form.
The nurse will start an intravenous line (insert a needle into a vein in the hand or arm) to administer medications. The intravenous line insertion feels like a pin prick, similar to having blood drawn. The vital signs (blood pressure, heart rate, and blood oxygen level) will be monitored before, during, and after the examination. The monitoring is not painful. Some patients will be given oxygen during the examination.
THE PROCEDURE — The colonoscopy will be performed while the patient lies on their left side. Medications will be administered through the intravenous line. Most endoscopy units use a combination of a sedative (to help patients relax), and a narcotic (to prevent discomfort). Many people sleep during the examination while others are very relaxed, comfortable, and generally not aware of the examination.
The colonoscope is a flexible tube, approximately the size of the index finger. It has a lens and a light source that allows the endoscopist to look into the scope or at a TV monitor. The image on the TV monitor is magnified many times so the endoscopist can see small changes in tissue.
The endoscope contains channels that allow the endoscopist to obtain biopsies (small pieces of tissue), remove polyps and to introduce or withdraw fluid or air. Polyps are extra growths of tissue that can range in size from the tip of a pen to several inches (doctors measure them in millimeters and centimeters). Most polyps are benign (not cancerous) but can turn into cancers if left to grow for a very long time. As a result, they are usually removed so they can be analyzed under the microscope. This does not hurt since the lining of the colon does not sense pain.
Air is introduced through the scope to open up the colon so that the scope can be moved forward and to allow the endoscopist to see. Patients may experience a feeling of bloating or gas cramps from the air as it distends the colon. Try not to be embarrassed about releasing the air through the rectum; patients should let their physician know if they are uncomfortable
RECOVERY — After the colonoscopy, a patient will be observed until the effects of the sedative medication are gone. The most common discomfort after colonoscopy is a feeling of bloating and gas cramps. Patients may also feel groggy from the sedation medications. Patients should not return to work that day. Most patients are able to eat a regular diet after the examination. Patients should ask about when it is safe to restart aspirin or blood thinning medications.
COMPLICATIONS — Colonoscopy is a safe procedure and complications are rare, but can occur: Bleeding can occur from biopsies or the removal of polyps, but it is usually minimal and stops quickly or can be controlled. The colonoscope can cause a tear or hole in the tissue being examined, which is a serious problem, but, fortunately, very uncommon. Adverse reactions to the medications used to sedate you are possible. The endoscopy team (doctors and nurses) will ask about previous medication allergies or reactions and about health problems such as heart, lung, kidney, or liver disease. The medications can also produce irritation in the vein at the site of the intravenous line. If redness, swelling, or warmth occur, warm to hot wet towels applied to the site may relieve the discomfort. If the discomfort persists, notify the endoscopy unit.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons.
AFTER COLONOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Some fatigue after the examination is common. Patients should plan to take it easy and relax the rest of the day.
The endoscopist can describe the result of their examination before the patient leaves the endoscopy unit. If biopsies have been taken or polyps removed, the patient should call for results within one to two weeks.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy
(www.askasge.org)
[1-3]
Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Rex, DK, Johnson, DA, Lieberman, DA, et al. Colorectal cancer prevention 2000: screening recommendations of the American College of Gastroenterology. American College of Gastroenterology. Am J Gastroenterol 2000; 95:868.
2. Lieberman, DA, Weiss, DG, Bond, JH, et al. Use of colonoscopy to screen asymptomatic adults for colorectal cancer. Veterans Affairs Cooperative Study Group 380. N Engl J Med 2000; 343:162.
3. Singh, H, Turner, D, Xue, L, et al. Risk of developing colorectal cancer following a negative colonoscopy examination: evidence for a 10-year interval between colonoscopies. JAMA 2006; 295:2366.
Colonoscopy is a safe procedure that provides information other tests may not be able to give. A colonoscopy is an examination of the lower part of the gastrointestinal tract, which is called the colon or large intestine (bowel). It is performed by an endoscopist, a physician with special training in endoscopy procedures. The colonoscope is inserted into the anus and advanced through the entire colon (to the cecum) and possibly a short distance into the small intestine. The procedure generally between twenty minutes and one hour.
REASONS FOR COLONOSCOPY — The most common reasons for colonoscopy are to evaluate the following: As a screening exam for anyone over age 50 Blood in the stool or rectal bleeding Dark/black stools Persistent diarrhea Iron deficiency anemia (a decrease in blood count due to loss of iron) Significant, unexplained weight loss, accompanied by gastrointestinal symptoms A family history of colon cancer To follow up an abnormal barium enema A history of previous colon polyps or colon cancer Surveillance in people with ulcerative colitis For the medical management of chronic inflammatory bowel disease Chronic, unexplained abdominal pain.
PREPARATION — The endoscopy unit will provide specific instructions about how to prepare for the examination. The instructions are designed to maximize safety during and after the examination, minimize possible complications, and allow the endoscopist to fully view the colon.
It is important to read the instructions ahead of time and follow them carefully; patients who have questions should speak with their healthcare provider or the endoscopy unit.
The inside lining of the colon must be cleaned of stool to permit the endoscopist to complete a thorough examination. This is accomplished by restricting what is eaten and by using purgatives. What to eat — As a general rule, patients should not eat any solid food for at least one day before the examination. Only clear liquids (such as juices without pulp, bouillon, ginger ale) or clear gelatin (flavored is fine, but without added fruit) are recommended. The doctor's office or endoscopy unit will supply a list of fluids that are allowed. Purgatives — There are two methods commonly used to empty the bowel of stool. The first involves drinking a gallon of an undigestible solution (Go-Lytely®, and others) that causes temporary diarrhea. It comes in several flavors, which, unfortunately, only partially mask a somewhat unpleasant taste. Refrigerating the solution may make it more palatable. Drinking such a large volume of cold solution may cause a patient to feel chilled, but the sensation is temporary. Do not add flavoring to the solution. Many patients say that drinking the purgative solution is the most unpleasant part of the examination.
The second method involves drinking a solution called Fleets® Phosphosoda, along with several cups of liquid. This preparation is easier to consume than the purgative described above. However, the solution contains a large amount of phosphorus, which may be a problem for people with heart or kidney conditions. Medications — Some medications, such as aspirin and iron preparations, should be discontinued for one to two weeks before the examination. Aspirin and pain killers such as Motrin (which contains ibuprofen) slightly increase the risk of bleeding. Patients who take a blood thinning medication should consult with their doctor as to when they should stop taking it. Patients should also ask about medications for diabetes, heart or lung disease, high blood pressure, or seizure disorders. Some medications should not be stopped, and many of them can be taken the examination. Patients who take antibiotics before dental procedures should ask if they will be needed before colonoscopy. Transportation home — Patients need to arrange for someone to escort them safely home after the examination. Although patients will be awake by the time of discharge, the sedative medications cause changes in reflexes and judgment that cause a person to feel well but can interfere with the ability to make decisions, similar to the effect of alcohol.
WHAT TO EXPECT — Prior to the endoscopy, a nurse will ask questions to ensure the patient understands the procedure and the reason it is planned. The nurse will ask questions to ensure the patient has prepared properly for the procedure. A doctor will also review the procedure, including possible complications, and will ask patients to sign a consent form.
The nurse will start an intravenous line (insert a needle into a vein in the hand or arm) to administer medications. The intravenous line insertion feels like a pin prick, similar to having blood drawn. The vital signs (blood pressure, heart rate, and blood oxygen level) will be monitored before, during, and after the examination. The monitoring is not painful. Some patients will be given oxygen during the examination.
THE PROCEDURE — The colonoscopy will be performed while the patient lies on their left side. Medications will be administered through the intravenous line. Most endoscopy units use a combination of a sedative (to help patients relax), and a narcotic (to prevent discomfort). Many people sleep during the examination while others are very relaxed, comfortable, and generally not aware of the examination.
The colonoscope is a flexible tube, approximately the size of the index finger. It has a lens and a light source that allows the endoscopist to look into the scope or at a TV monitor. The image on the TV monitor is magnified many times so the endoscopist can see small changes in tissue.
The endoscope contains channels that allow the endoscopist to obtain biopsies (small pieces of tissue), remove polyps and to introduce or withdraw fluid or air. Polyps are extra growths of tissue that can range in size from the tip of a pen to several inches (doctors measure them in millimeters and centimeters). Most polyps are benign (not cancerous) but can turn into cancers if left to grow for a very long time. As a result, they are usually removed so they can be analyzed under the microscope. This does not hurt since the lining of the colon does not sense pain.
Air is introduced through the scope to open up the colon so that the scope can be moved forward and to allow the endoscopist to see. Patients may experience a feeling of bloating or gas cramps from the air as it distends the colon. Try not to be embarrassed about releasing the air through the rectum; patients should let their physician know if they are uncomfortable
RECOVERY — After the colonoscopy, a patient will be observed until the effects of the sedative medication are gone. The most common discomfort after colonoscopy is a feeling of bloating and gas cramps. Patients may also feel groggy from the sedation medications. Patients should not return to work that day. Most patients are able to eat a regular diet after the examination. Patients should ask about when it is safe to restart aspirin or blood thinning medications.
COMPLICATIONS — Colonoscopy is a safe procedure and complications are rare, but can occur: Bleeding can occur from biopsies or the removal of polyps, but it is usually minimal and stops quickly or can be controlled. The colonoscope can cause a tear or hole in the tissue being examined, which is a serious problem, but, fortunately, very uncommon. Adverse reactions to the medications used to sedate you are possible. The endoscopy team (doctors and nurses) will ask about previous medication allergies or reactions and about health problems such as heart, lung, kidney, or liver disease. The medications can also produce irritation in the vein at the site of the intravenous line. If redness, swelling, or warmth occur, warm to hot wet towels applied to the site may relieve the discomfort. If the discomfort persists, notify the endoscopy unit.
The following symptoms should be reported immediately: Severe abdominal pain (not just gas cramps) A firm, distended abdomen Vomiting Fever Bleeding greater than a few tablespoons.
AFTER COLONOSCOPY — Although patients worry about discomforts of the examination, most people tolerate it very well and feel fine afterwards. Some fatigue after the examination is common. Patients should plan to take it easy and relax the rest of the day.
The endoscopist can describe the result of their examination before the patient leaves the endoscopy unit. If biopsies have been taken or polyps removed, the patient should call for results within one to two weeks.
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.
This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.
A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine
(www.nlm.nih.gov/medlineplus/healthtopics.html)
The American Society of Gastrointestinal Endoscopy
(www.askasge.org)
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Use of UpToDate is subject to the Subscription and License Agreement. REFERENCES 1. Rex, DK, Johnson, DA, Lieberman, DA, et al. Colorectal cancer prevention 2000: screening recommendations of the American College of Gastroenterology. American College of Gastroenterology. Am J Gastroenterol 2000; 95:868.
2. Lieberman, DA, Weiss, DG, Bond, JH, et al. Use of colonoscopy to screen asymptomatic adults for colorectal cancer. Veterans Affairs Cooperative Study Group 380. N Engl J Med 2000; 343:162.
3. Singh, H, Turner, D, Xue, L, et al. Risk of developing colorectal cancer following a negative colonoscopy examination: evidence for a 10-year interval between colonoscopies. JAMA 2006; 295:2366.
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