The Gastroenterology Center of Connecticut recommends colonoscopy as the preferred test to prevent colorectal cancer. Colonoscopy is the only test that is able to screen for, detect, and treat/remove significant precancerous colon lesions during one exam.
What is Cologuard®?
Cologuard® is a new, noninvasive colon cancer screening test that does not require any preparation or dietary changes, and is done on a stool sample collected at home. It was designed to be used by men or women over the age of 50 who are at average risk for colon cancer. It should NOT be used by those who have a higher than average risk for colon cancer, such as those with a family history of colon cancer or precancerous polyps, or those with a personal history of inflammatory bowel disease.
How does Cologuard® work?
Every day the normal colon lining sheds small numbers of cells. If cancerous or precancerous tissue is in your colon, those abnormal cells can also be shed into stool as it passes through your colon. Cologuard® uses laboratory technology to find if there is DNA from abnormal cells or evidence of blood in the stool. Cologuard® is not a genetic test; it only looks for altered DNA associated with colon cancer and precancerous cells that may be present in the colon at the time of the test.
How is the Cologuard® test done?
The Cologuard® test requires collecting a stool sample at home with a special kit that is provided by Cologuard®. The patient places a plastic collection bucket on the toilet seat, collects a stool sample in the collection bucket, and then collects a second sample by scraping the stool with a collection probe. A preservative liquid is then poured into the collection bucket, and both samples are shipped to a laboratory for evaluation within 3 days of collection. A physician will review the results of the study and will order additional tests as needed.
All positive Cologuard® results should be followed by a diagnostic colonoscopy. After a negative result, patients should continue participating in a routine screening program. Guidelines have not been established for how often the Cologuard® test should be performed.
How does Cologuard® compare to other non-invasive colon cancer screening tests?
The fecal immunochemical test, also known as "FIT", is a stool-based, noninvasive, colon cancer screening test that has been around for many years. The FIT test is widely available and has been included in all of the U.S. colon cancer screening guidelines.
In clinical studies, Cologuard® found 92% of colon cancers and 42% of advanced precancerous tissue in the colon. This also means that it missed 8% of colon cancers and did not detect almost 60% of advanced precancerous tissue. When compared to the FIT test, it was more effective at detecting colon cancer, however as with any test false positives (test is positive in a person who DOES NOT have the disease) and false negatives (test is negative in a patient who DOES have the disease) can occur. Cologuard® was positive in 13% of people without cancer (false-positive) whereas the FIT test has a lower 5% false-positive rate.
How much does Cologuard® cost?
The cost for a Cologuard® test is $599. The cost for the more traditional non-invasive FIT test is $25.
Will my insurance cover the Cologuard® test?
Since Cologuard® is a new test, insurance companies can take a year or more to update their insurance coverage policies. Medicare reports that the Cologuard® test will be covered once every three years for asymptomatic patients aged 50 to 85.
If a Cologuard® test is positive, a colonoscopy will be needed to definitively see whether cancer or precancerous tissue is present. In this case, the colonoscopy may be covered by insurance as a "diagnostic" test rather than as a "screening" test and additional co-payments or deductibles may apply. Patients considering using the Cologuard® test should check with their insurance provider first to determine coverage.
Who should consider using Cologuard®?
- Those patients who decline a screening colonoscopy BUT would agree to undergo colonoscopy if the Cologuard is positive.
- Those patients with chronic medical conditions which increase their personal risk for complications from screening colonoscopy, but have an acceptable risk profile for a diagnostic/therapeutic colonoscopy.
Colon cancer screening tests are an important tool to help detect and prevent colon cancer. With appropriate screening and early detection, colon cancer can be treated early or even prevented. There are now many options for colon cancer screening available. In most cases, colonoscopy remains the best test colon cancer screening since it can detect and treat/remove significant precancerous colon lesions during one exam.
The physicians of the Gastroenterology Center of Connecticut urge you to talk to your doctor about which colon screening test is right for you.