By Martha A. Simpson, D.O., M.B.A.
Associate Professor of Family Medicine
Ohio University College of Osteopathic Medicine

READER AND HER FRIENDS MAY NEED DIFFERENT COLON SCREENING TESTS

Question: A while ago you wrote about following your doctor’s advice regarding screening tests for colon cancer. Which tests are best? My friend says a colonoscopy is the real test, but my doctor says I don’t need one. What are the recommendations for colon cancer screening?

Answer: As with many things in medicine, there are several ways to screen for colon cancer. The test that is recommended by your physician is based on your personal risk for developing colon cancer. The primary risk factor associated with the development of colon cancer is a family history of the disease. Also, a personal history of ulcerative colitis or colon polyps increases your risk. People who eat a high-fat, low-fiber diet and those who are overweight are also at increased risk for colon cancer.

Age is also a very important factor in overall colon cancer risk. Although colon cancer does sometimes strike at younger ages, about 90 percent of all cases are in people over 50.

If you are at average risk, which means you have none of the above listed risk factors, it is acceptable to use simpler and less expensive tests. I assume your doctor placed you in this average risk category. In cases like this, I usually recommend that the patient be screened using the fecal occult blood test and a flexible sigmoidoscopy. A digital rectal examine is also a good idea. All three tests should be completed annually starting at age 40.

The fecal occult blood test is performed on stool samples to see if small amounts of blood -- not readily visible -- are present. Generally, this is done on three separate stool samples. The doctor gives you a special card to take home. You then collect the specimen, place it on the card, seal it up and return the card to the doctor. If any of the three specimens are positive for occult (hidden) blood, you need a colonoscopy. If all are negative, a flexible sigmoidoscopy should be done.

Flexible sigmoidoscopy is like colonoscopy with a shorter tube. Research shows that more than 50 percent of colon cancers are within reach of the sigmoidoscope. This test can be done in a physician’s office rather than the hospital out-patient setting needed for a colonoscopy. Also, you generally do not need to be sedated for this procedure, whereas with a colonoscopy, the use of sedating drugs is standard practice.

Most doctors recommend a screening colonoscopy for people over 50 who are of average risk. During a colonoscopy your doctor can examine the entire colon. Any polyps that are discovered can be removed at the time of the exam. If there are no polyps present and the colon is otherwise normal, your doctor will probably recommend a repeat in 7 to 10 years.

A newer test that is gaining in popularity is the virtual colonoscopy. This is a C-T X-ray of the colon. This can be a very good test, but it cannot find small polyps and it cannot remove polyps. If polyps are found during a virtual colonoscopy, you will still need a regular colonoscopy to remove them.

It is good that you are so interested in these screening procedures that you are discussing them with friends and relatives. You and your friends should work with your individual doctors to determine which screening test is best. The answer for each one of you may be different.

Family Medicine® is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701, or via e-mail to readerquestions@familymedicinenews.org. Medical information in this column is provided as an educational service only. It does not replace the judgment of your personal physician, who should be relied on to diagnose and recommend treatment for any medical conditions. Past columns are available online at www.familymedicinenews.org.