Q: I've seen ads for at-home colon cancer tests that don't require a colonoscopy. How effective are these tests?
A: These types of tests use stool samples to look at your DNA to see if it's altered by precancerous or cancerous cells. As part of its normal process, our bodies shed DNA in our colons all the time, and the DNA is passed into the stool. The problem with this type of testing is it detects cancer but does not perform as well in detecting precancerous cells from a polyp. Remember that at-home DNA stool tests are only for those who have no family history of colon cancer, no personal history of polyps and no symptoms.
Polyps are the growths that most often lead to colon cancer, and polyps are common. Regardless of the type of polyp, an at-home DNA stool test will not identify the polyps unless they are have already turned into cancer. The most effective and thorough method to screen for colon cancer is a colonoscopy. During a colonoscopy, if the doctor sees a polyp, it can be removed during the exam, thus preventing cancer.
Everyone starting at age 50 should have a colon cancer screening. The American Cancer Society has even recently announced that they support screening to start at age 45. If you have a family history of colon cancer, your doctor may suggest beginning the screening process at an earlier age. As with most cancers, early detection is a major factor in treatment and full recovery.
- Dr. Colleen Schmitt, Galen Digestive Health; member, Chattanooga-Hamilton County Medical Society