As a board-certified colon & rectal surgeon, I’m often asked about the differences between colonoscopies with your doctor vs. the Cologuard at-home test. Cologuard has raised lots of hype recently with all the tv, print and digital advertising. Questions have been raised: Is Cologuard as safe as a colonoscopy? Is Cologuard as effective as a colonoscopy? Unfortunately, the answer is no.
Cologuard does not prevent colon cancer like colonoscopies do
Cologuard is a do-it-yourself, mail-in DNA test that helps detect some colon cancers—but it’s not a great preventative because it detects cancers only AFTER you have developed it. On the other hand, a colonoscopy PREVENTS colon cancer by removing the potentially cancerous polyps before they become cancerous. Colonoscopies detect 92% of colorectal cancers and precancerous polyps. That’s a big, potentially lifesaving difference that supports colonoscopy over other screening methods.
As a colonoscopy provider, I will carefully examine your large bowel using a thin, high-tech tube with a tiny camera at the end, and remove cancer-causing polyps. The procedure is completely painless, and takes less than 30 minutes. The polyps are sent to the lab and analyzed to identify the type of polyp(s) you have. That way I know when we need to see you next.
Cologuard, however, involves no visual element and no removal of cells. It detects the presence of abnormal DNA through testing your stool—and 42% of the time it does not catch precancerous polyps. It detects only 69% of polyps with high-grade dysplasia, which is a term that describes how much your polyp(s) looks like cancer under the microscope. These statistics published by the government’s National Institute of Health (NIH) provide troubling data, and indicate Cologuard is far less effective than colonoscopy.
The Cologuard process can get messy (and expensive!) real quick
What happens if your Cologuard test is positive? You will still need a diagnostic colonoscopy to determine next steps, which most insurances don’t cover at 100% if you’ve already tested with Cologuard. This is problematic because its manufacturer reports up to 13% of people tested are incorrectly diagnosed by Cologuard as having polyps, potentially cancer-causing ones. A false positive like that can wind up costing patients a couple thousand dollars.
A Cologuard test is better than no test
Cologuard and a similar FIT test do serve specific people well. They can be useful to those where medical services are difficult to access or for people who cannot be sedated. It can also be a good method for people who must absolutely refuse getting a colonoscopy. Frankly, our practice seldom has patients who refuse, thanks in part to the primary care and ob/gyn physicians we partner with to ensure patients are properly educated on how effective only colonoscopy is.
It’s estimated that 20 million Americans skip colorectal screenings, so a case can be made that any screening is better than no screening. We believe increased awareness that only colonoscopy can prevent colon cancer is the missing message. Let’s get the word out!
Hands down, just get a colonoscopy. It remains the gold standard with decades of proven results. Colonoscopy results are complete and more reliable, giving you peace of mind and preventing future colorectal cancer.