I have heard that colorectal cancer deaths are usually preventable through screening procedures. I am 60 years old; should I have some kind of test performed?

Colorectal cancer is the third most common cancer among people in the United States, making it a major public health concern. However, colorectal cancer can be prevented with timely and effective screening, which is the search for cancer and precancerous polyps in people who don’t have symptoms.

Colorectal cancer has several features that make it ideal for screening. First, it is both common and serious (fatal if not identified early and if left untreated). Second, it has a readily identifiable and slow-growing precursor lesion, the adenomatous polyp, removal of which prevents cancer progression. Third, colorectal cancer, once developed, is believed to advance relatively slowly from stages that are readily curable by surgery to stages that are not. Fourth, currently recommended prevention tests are widely available.

Because colon cancer is most common in adults ages 50 to 70, colon cancer screening should start at age 50 to prevent the development of colon cancer in later years. Some patients may require screening starting at an earlier age.

Diagnostic tests

Colon cancer screening can involve one or more diagnostic tests, including:

• Fecal occult blood test, a simple, at-home procedure that checks stool samples for hidden (occult) blood, which can be the sign of cancer, polyps or other internal disorders. This test should be performed in combination with flexible sigmoidoscopy.
• Flexible sigmoidoscopy, a procedure using a flexible, lighted tube that detects cancer or polyps inside the rectum and lower colon. The sigmoidoscope can view about one-third of the colon and is an effective tool for colon cancer screening in combination with fecal occult blood testing. The major drawback of flexible sigmoidoscopy is that it typically only examines the lower one-third of the colon. If a flexible sigmoidoscopy is performed and an abnormality such as a polyp is detected, colonoscopy will be necessary to remove that lesion and to examine the rest of the colon for other abnormalities.
• Barium enema/X-ray, which involves obtaining X-rays of the colon following administration of barium. A barium enema is not as effective as colonoscopy in detecting polyps or early colon cancer. The other distinct disadvantage of barium enema is that it is a diagnostic test only. If polyps or other abnormalities are detected, a colonoscopy will be needed to confirm any abnormal results or to remove the polyp or other growth noted on the initial barium X-ray.
• Colonoscopy, the most reliable, accurate method of colon cancer screening. It is widely considered to be the “gold standard.” The major advantages of colonoscopy over other screening tests are that the entire colon can be visualized and polyps can be removed at the time of colonoscopy. Other lesions can be biopsied as well as photographed.
• CT colonography (virtual colonoscopy), an X-ray test designed to look for colon polyps and colon cancer. Virtual colonoscopy is a relatively new technology, and it requires a bowel preparation similar to that used for colonoscopy. Patients then undergo a CT scan, before which their colon is inflated with air. A CT scan is then obtained, and images are constructed that allow the colon to be visualized.

— Dr. Curtis A. Baum, Cotton-O’Neil Clinic, from Healthy Times, Stormont-Vail HealthCare, contributed information for this article.