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Cologuard vs Colonoscopy

3d rendered illustration of a polyp removal

Colorectal cancer is the third most common cancer in the United States among both men and women and is the second leading cause of cancer-related deaths. Colon cancer screening has been shown to significantly reduce the risk of colon cancer and death. Almost all cancers in the colon and rectum start as a small polyp or a growth in the lining of the colon. Over years, these polyps can slowly grow and transform into a cancer. Unfortunately, by the time a colon cancer is causing symptoms, such as bleeding or discomfort, it is usually large and already reached an advanced stage. This is why colon cancer screening is so important! The best time to treat a cancer is before it develops, not after…more on this later.

Colonoscopy is the gold standard for colon and rectal cancer screening and it is a quick, safe and painless procedure.   A bowel preparation is taken at home to clean out the colon the day before, which allows us to detect and remove any polyps that are present. Under sedation, a flexible lighted instrument is passed through the colon and rectum. The colon is carefully evaluated and if any polyps are seen they are removed. If a mass or lesion is too big, it is simply biopsied. The examination has an extremely small risk of complications (0.1% to 0.2% risk of bleeding or perforation). The goal is to prevent you from getting colon cancer by removing the polyps or precursors to colon and rectal cancer. Remember, when you have these polyps, you don’t know you have them because they are too small to cause problems. The secondary goal to screening would be early detection of cancer that can be curable if treated it is early stages. The recommendations by the American Cancer Society are to have a screening colonoscopy every 10 years (this timing is shortened if you have a history of colonic polyps, a family history of colorectal cancer or certain other risk factors).

Cologuard is a newer, non-invasive test for detecting colon cancer – perhaps you’ve seen television ads for it. Every day the lining of your colon sheds cells. These cells are expelled with your stool. Cologuard uses advanced stool DNA technology to find abnormal DNA and blood that may be associated with cancer or large precancerous lesions or polyps. If a Cologuard test is positive, you will need a colonoscopy for further evaluation.   In a 10,000 patient clinical study, Cologuard found 92% of colon cancers but only 69% of large polyps. It is not very good at findings small polyps. In contrast, colonoscopy can detect colon cancer over 95% of the time and miss rate of large polyps is only 6-12%.

Although the Cologuard test is a great advancement for the screening of colorectal cancer, in our view, it is not great for preventing colorectal cancer. The goal in screening for colorectal cancer is to REMOVE POLYPS BEFORE THEY EVER BECOME CANCER, not merely detecting a cancer once it has formed. As we mentioned earlier…it is always better to PREVENT CANCER than to treat it once it exists! Colonoscopy remains the best method allowing us to detect and remove polyps that may progress to cancer in the future. Currently stool tests aren’t sensitive enough for detecting small polyps and we reserve its use for people who cannot undergo a colonoscopy due to other medical conditions.

Colonoscopy remains THE GOLD STANDARD for colorectal cancer screening. It is a safe procedure with a proven track record and can, literally, save your life. The procedure itself is a non-event – you’ll be enjoying lunch within an hour after finishing and back to work the next day. Please don’t procrastinate and put yourself at risk — get your colonoscopy scheduled and get on with living a healthy, happy life.