Colon Cancer Screening
Frederick H. Opper, M.D., F.A.C.P., F.A.C.G., A.G.A.F.
Colon cancer screening is one of the success stories of preventive medicine. Many tests are available for colon cancer screening and the proper choice of testing should be based upon the patient's health, risk of developing colon cancer and personal preference. Some screening tests (such as Hemoccult cards which test for hidden blood in the stools) help to identify cancer at early stages. Cancer caught in an early stage is more easily treated and potentially cured. Other screening tests, primarily colonoscopy, can not only detect early cancers but can actually prevent the development of cancers by identifying and removing precancerous growths (polyps) before they turn malignant. This strategy has been highly successful. Regular screening and polyp removal can reduce the risk of cancer development by 90%.
People should start colon cancer screening by age 50. People at higher risk for developing the disease should start earlier. For example, people who have one first degree relative (parent, sister, brother or child) who has had colon cancer, should start screening by age 40 or by 10 years earlier than the youngest age at which colon cancer was diagnosed in their family (whichever comes younger). The same guidelines hold true for people with 2 second degree relatives (grandparent, aunt, uncle) with colon cancer.
People considered to be at average risk for colon cancer should discuss options with their healthcare provider. Options include: colonoscopy, CT scan colonography, flexible sigmoidoscopy, barium enema and stool tests. The stool tests include tests for blood, DNA, and immunologic tests. All tests have their pros and cons and the approach needs to be individualized for each patient. Patients at increased risk are preferentially screened with colonoscopy.
Colonoscopy allows a physician to examine the lining of the entire colon using a thin, flexible, lighted tube (colonoscope). The patient must prepare the bowel for examination. This involves drinking a medicine that causes diarrhea (temporarily) to clean out the colon for the physician to be able to see. The exam is usually done with intravenous sedation. Once sedated, a patient cannot drive or go to work until the next day.
Colonoscopy is considered our best test to see the colon. It is the only screening that allows for removal of precancerous growths (polyps). Colonoscopy entails greater risks than the other screening methods. The main risks include bleeding (primarily as a result of removing polyps) and an approximately one in a thousand chance of making a tear in the wall of the colon.
The key to colon cancer prevention is screening. The age at which to start screening, and the method of screening should be discussed with your primary healthcare provider. Remember that screening can save lives.
Frederick H. Opper, M.D., F.A.C.P., F.A.C.G., A.G.A.F.