Mercy's Dr. Jeffery Nelson Discusses: What's The Deal With Home Colon Cancer Tests?

November 06, 2020


Dr. Jeffery Nelson, Surgical Director of The Center for Inflammatory Bowel and Colorectal Diseases, part of The Institute for Digestive Health and Liver Disease at Mercy, was recently asked by VeryWell Health and Medical Daily to expound on the issue of home colon cancer testing kits. Here are his responses…

Patients do ask about this. There are three types of stool tests. Fecal occult blood testing (FOBT) is the least sensitive and not specific for blood being produced in the colon (it just detects blood in the stool from any source) and has been around for a long time. The problem with it, besides sensitivity, is that you should follow a special diet before doing it (no red meat, etc). The newer tests are more sensitive, but very expensive. Fecal immunochemical testing (FIT) also tests for blood in the stool but is more sensitive than FOBT and you don’t have to follow a special diet before the test. Also, FIT tests are specific to blood produced in the colon and not the upper GI tract. It has to be repeated every year, however. Cologard is the fecal DNA test. It tests for abnormal DNA that cancers or polyps specifically in the colon would produce. Cologard should be repeated every three years if normal. All of these tests are for persons at average risk – no personal or family history of colorectal cancers or polyps, or any genetic syndromes. Everyone else should get colonoscopy for surveillance. The other problem with these tests is that they have high false positive rates and require follow up colonoscopy anyway if the test comes back positive. This can lead to emotional stress in the interim.

About Mercy

Founded in 1874 in Downtown Baltimore by the Sisters of Mercy, Mercy Medical Center is a 183-licensed bed, acute care, university-affiliated teaching hospital. Mercy has been recognized as a high-performing Maryland hospital (U.S. News & World Report); has achieved an overall 5-Star quality, safety, and patient experience rating (Centers for Medicare and Medicaid Services); is A-rated for Hospital Safety (Leapfrog Hospital Safety Grade); and is certified by the American Nurses Credentialing Center as a Magnet™ hospital. Mercy Health Services is a not-for-profit health system and the parent company of Mercy Medical Center and Mercy Personal Physicians.

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