3 gastroenterologists share their thoughts on Exact Sciences' Cologuard

Exact Sciences' colon cancer screening test, Cologuard, is polarizing. The test's noninvasive nature makes it a popular alternative for colonoscopy-fearing patients, but gastroenterologists are conflicted.

According to a 2014 study, published in the New England Journal of Medicine study and sponsored by Exact, the test has 92 percent sensitivity rate when detecting colorectal cancer, a 42 percent sensitivity detecting precancerous lesions and a 69.2 percent detection rate polyps with high-grade dysplasia. Cologuard has an 86.6 percent specificity among patient with non-advanced or negative findings and an 89.89 percent specificity among patients with negative colonoscopy results..

The widely-marketed test carries a $649 price tag and must be repeated every three years, according to a Forbes article. Although the test is covered by most payers, if a positive test is returned, a patient likely pays out of pocket for a follow-up colonoscopy to confirm the diagnosis. The Forbes article also states Cologuard has an 8 percent false-negative rate and a 13 percent false-positive rate

Becker's ASC Review asked three gastroenterologists for their thoughts on Cologuard.

David Frantz, MD, Revere Health (Provo, Utah): I am a strong proponent for screening — any screening. My father was diagnosed with colorectal cancer after experiencing months of narrow caliber stools and rectal bleeding. I was in my [gastroenterology] fellowship at the time, and I was shocked to learn he had put off his colonoscopy. It turned out he was afraid of the procedure. I believe any of the recommended screening methods would have picked up his cancer early before his late presentation with stage 4 disease.

When patients come to me and ask what screening method they should [use], I tell them my father's experience, and I tell them I do not care which test they choose just as long as they do something. Screening saves lives, and I will support whatever method they prefer. However, I make it a point to go over the characteristics of each test. I tell them the most sensitive test we have right now is high-definition optical colonoscopy. This is the test I chose when I started screening. If my patient has health conditions that prevent optical colonoscopy then I recommend virtual colonoscopy because it seems to have the next highest sensitivity. If this is not an option, then I recommend Cologuard.

I believe Cologuard is a great test for patients who are not healthy or too fearful to have an optical or virtual colonoscopy. However, it worries me primary care providers and patients are opting for Cologuard as [their] first choice simply because of the convenience factors. In my experience, these patients have not been properly educated on the test characteristics and the test’s sensitivity. Many patients do not realize that Cologuard tends to pick up lesions that are larger and more advanced. During my colonoscopy, I was found to have two small adenomas. I doubt that Cologuard or even the virtual colonoscopy could have picked up on these lesions because of their size.

Glenn Englander, MD, of GastroGroup of the Palm Beaches (Fla.): I have recommended it to numerous patients. My specialty, obviously, has a vested interest in doing colonoscopies. I would be remiss, however, if I did not put my patients interest before my own. If a patient had extreme anxiety about getting colonoscopy, I will recommend Cologuard.

Typically, [patients] are anxious about anesthesia, or they know a horror story where someone had a perforation from a colonoscopy, or they can not get past the concept that anyone is 'putting something up there.' Ideally the patient should be of average risk. There should not be a family history of colon cancer [either]. Even family members with cancer of the uterus, ovary and stomach may have higher risk, and people with significant rectal bleeding, iron deficiency or bowel changes really need to have [a] colonoscopy [instead of Cologuard].

Pradeep Kumar, MD, of Austin (Texas) Gastroenterology: "Colon cancer is the second leading cause of cancer deaths in the U.S. It can be prevented … because colon cancer almost always arises from precancerous polyps that take years to develop into cancer. By finding and removing precancerous polyps, we can prevent colon cancer.

So far, the best way to find precancerous polyps is to perform screening colonoscopy on asymptomatic individuals beginning at age 50 (45 for African-Americans). The dilemma is that at least 40 percent of people eligible to be screened do not get screened. The reasons are numerous, including costs of time and money, access to care, not being aware of screening recommendations and, frankly, just not wanting to have a colonoscopy.

It is the last group of patients for which Cologuard is suited. For people who just do not want to get a colonoscopy, knowing that it can prevent colon cancer, Cologuard is an option. According to their website — which will convey their data in the most favorable terms – Cologuard has a 42 percent high-risk polyp detection rate. These are the most dangerous polyps, which have the greatest chance of developing into colon cancer, and 42 percent is much better than nothing.

So, I would recommend Cologuard to those who insist on not getting a colonoscopy. However, I would not recommend it for any other group. If the issue is time and money, I would discuss those constraints in the context of the cost of getting colon cancer. If it is access to care, whatever test they have access [to] should get performed. If it is not being aware of screening recommendations, I would make them aware. Only for those who know and still don't want a colonoscopy would I advocate for Cologuard. If the detection rate of dangerous polyps is 42 percent, what is left unsaid is that 58 percent of the most dangerous polyps are not detected by Cologuard, and that is unacceptable.

Update: Scott Larrivee, an Exact Sciences spokesman said, "Colorectal cancer is the number two cancer killer in the U.S., yet a third of all American adults over the age of 50 are not current with screening guidelines for the disease. Cologuard was designed to help more people get screened and it’s doing just that. Approximately half of all Cologuard users age 50 to 75 have never been screened before. Using a single stool sample collected at home, Cologuard has been shown to be a highly sensitive, noninvasive test which finds both cancer and precancer, including 69 percent of polyps with high grade dysplasia – those with the highest potential to become cancerous – and 94 percent of early Stage cancer (AJCC Stage 1 and 2) , which are highly treatable. As a laboratory test, daily consistency of analysis is ensured in comparison to the natural variability encountered with procedure-based investigations. As we all work to achieve a world without colorectal cancer, Cologuard provides an essential, frontline screening approach that accurately and cost-effectively identifies those patients requiring a diagnostic colonoscopy, while sparing those who do not from the personal inconveniences and risks associated with an invasive medical procedure."

Note: Responses were updated for style and content. Also, this story was updated to include the above statement from Exact Sciences. 

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