Colorectal Cancer Screening in Average-Risk Adults

Who developed these recommendations? The American College of Physicians (ACP) developed these recommendations. The ACP is a professional organization for internal medicine doctors, who specialize in health care for adults. What is the problem and what is known about it so far? Cancer of the colon or rectum (colorectal cancer, or CRC) is the second leading cause of cancer death in the United States. Screening for CRC helps find signs of cancer or abnormal growths (polyps) in the intestine that can be removed to prevent them from turning into cancer. This is important because CRC often does not cause symptoms until it has become advanced and more difficult to cure. Several types of screening tests are available. Stool-based tests, such as the fecal immunochemical test (FIT) or the guaiac fecal occult blood test (gFOBT) can be done at home and mailed to a laboratory. The sample is tested for blood, which can be a sign of polyps or cancer. If blood is found, these tests should be followed with a colonoscopy. Colonoscopy is a direct visualization test that uses a tube to view inside the entire colon. Flexible sigmoidoscopy uses similar technology to look directly at the lower portion of the colon. Both of these tests are invasive, require preparation to empty the bowel, and may require sedation. Different organizations have different recommendations about which tests to use, when to start and stop, and how often they should be done in average-risk adults. How did the ACP develop these recommendations? The ACP Clinical Guidelines Committee reviewed selected guidelines on CRC screening developed by national organizations or commonly followed by doctors in the United States. They evaluated the quality of these guidelines to help doctors and average-risk adults decide about CRC screening. They do not address adults at high risk for CRC or those who have symptoms like abdominal pain or bleeding. What are the benefits and harms of CRC screening in average-risk persons? Screening can lead to early detection and treatment, which reduces development of and death from CRC. However, screening tests may also cause harms, which vary by person and screening method. Harms from stool-based tests (FIT and gFOBT) include a higher rate of false-positive results, which is when the test shows an abnormality that is not cancer. If the test shows an abnormality, a more invasive test, such as colonoscopy, is required. Harms from direct visualization tests include bleeding, perforation, and the need for sedation during and preparation before a colonoscopy. However, these tests are more sensitive and allow for longer intervals between screening. What does average-risk mean? For the purpose of these recommendations, average-risk means an adult who does not have any of the following: Family history of CRC History of CRC, noncancerous polyps, or inflammatory bowel disease Certain genetic syndromes What does the ACP suggest that patients and doctors do? Clinicians should screen for CRC in average-risk adults aged between 50 and 75 years. Clinicians and patients should discuss screening tests and their benefits, harms, and costs, while taking into account each patient's personal preferences. The success of screening depends on patients following up on abnormal results and repeating testing at designated intervals. Suggested screening tests and intervals include: FIT or gFOBT every 2 years. Colonoscopy every 10 years. Flexible sigmoidoscopy every 10 years accompanied by FIT every 2 years. Clinicians should not continue to screen for CRC in average-risk adults aged 75 years or older or in adults with a life expectancy of 10 years or less. Questions you may want to ask your doctor What is my personal risk for CRC? When should I start screening for CRC? Which CRC screening tests are available to me? What are the benefits and harms of each method? How often should I be screened? How should I prepare myself? When should I stop CRC screening?