Colonoscopy is the most accurate test for cancer of the colon and rectum, proven to detect the disease early and save lives. But even a very good test can be done too often. So why are anywhere from one-third to one-half of Americans over 50 not getting the recommended tests for colorectal cancer? One reason this screening rate lags behind those for some other cancers may be an overemphasis on colonoscopy as the screening test of choice in this country. Many experts, organizations and media spokespeople such as Katie Couric have promoted colonoscopy as the best colorectal screening test. As a result, it has become the most frequently used screening test for colorectal cancer in the U.S.. Here’s when you need it, and when you might not.
So, at what age has colonoscopy proven to be effective enough at preventing cancer to justify its routine use in the general population? Most experts agree that adults who have an average risk of developing colon cancer should have a baseline colonoscopy at age 50 and, if the results come back normal, a follow-up colonoscopy every 10 years thereafter.
However, 50 is not the magic number for everyone. Researchers have identified several risk factors that are believed to make some individuals more prone to developing colon cancer, and therefore may warrant testing at a younger age. These risk factors include:
- Having a first-degree relative (a parent, sibling or child) who was diagnosed with colorectal cancer or polyps – Individuals with a family history colorectal cancer or polyps may have an elevated risk of developing the condition themselves, particularly if a close relative was diagnosed at a young age. As a general rule of thumb, these individuals should begin screening 10 years before the age of the youngest case in his or her immediate family. For example, if an individual’s parent was diagnosed with colon cancer at age 45, that individual should have his or her first colonoscopy by age 35.
- Being of African-American descent – Due to a disproportionately higher incidence of colon cancer among the African-American population, some physicians recommend a baseline colonoscopy at age 45 or earlier for African-Americans.
- Having certain hereditary conditions – Individuals who were diagnosed with familial adenomatous polyposis, hereditary nonpolyposis colon cancer (Lynch syndrome) or other inherited conditions may have a heightened risk of developing colorectal cancer. For these individuals, a physician may recommend earlier screenings on a case-by-case basis.
The following steps can help protect against colon cancer:
- Make lifestyle changes. Eat more fruits, vegetables, and whole grains, and less fatty foods and red or processed meat. Lose excess weight, exercise, limit alcohol, and don’t smoke.
- Get accurate test results. Carefully follow your doctor’s instructions preparing your bowels before the procedure. If you have questions, call the office and go over them with the nurse.
- Consider alternatives. If you’re at average risk, talk to your doctor about other test options, and ask your insurer about coverage. Other tests that can find polyps and cancer, and require bowel prep, include flexible sigmoidoscopy, which uses a short tube to examine the rectum and lower colon, and CT colonography, in which a tube is inserted into the rectum and an X-ray scanner creates pictures. Stool tests can find signs of cancer and don’t require bowel preparation. Abnormalities found on an alternative test must be followed up with a colonoscopy.
Finally, everyone should be screened for colorectal cancer according to the individual guidelines recommended by a physician. Colon cancer can be one of the most preventable types of cancer – if a patient takes a proactive role in his or her own health care.