It’s been difficult for TV watchers to avoid the sprightly Cologuard box jumping around on its spindly blue legs, beckoning viewers to take an at-home, stool-based test for colorectal cancer. Joining in the multimillion-dollar national public relations and advertising blitz by Cologuard’s maker, Exact Sciences, are singer/actor Harry Connick Jr., golfer Jerry Kelly, and the Green Bay Packers.

Celebrity endorsements of health care products are nothing new. As early as 1958, Milton Berle’s jokes about Miltown, an antidepressant, were promoted to gossip columnists by the drug’s maker. Today’s direct-to-consumer marketing makes Berle’s efforts seem tame in comparison. Many such campaigns, including the one for Cologuard, seem like public health campaigns that are barely recognizable for what they really are: product advertisements.

The increased attention to Cologuard has resulted in more than 1.3 million people using the test. And with the recent announcement of a marketing partnership with Pfizer that will increase the size of the sales force promoting Cologuard to primary care physicians and hospitals, this may be just the beginning.


Make no mistake: Increased screening for colorectal cancer is important. It’s the third most common type of cancer (excluding skin cancer) in the United States, and is expected to kill more than 50,000 Americans this year.

But many gastroenterologists like me are concerned about the referral cases we’re seeing for follow-up colonoscopies triggered by positive Cologuard tests, especially those in which Cologuard should not have been prescribed in the first place. Many of us are also concerned that an outsized focus on convenience is overshadowing serious limitations of the test.

For me, it’s personal. I will never forget trying to find the right words to comfort my uncle who was dying from colon cancer — a disease I have spent my professional life trying to prevent.

There are four main ways to screen for colorectal cancer. (Screening means trying to find hidden cancer in seemingly healthy people.) Colonoscopy is the gold standard. It uses a flexible, lighted tool called a colonoscope to view the entire colon and remove cancerous and precancerous growths called polyps if they are detected. CT colonography uses a CT scanner and computer programs to create a three-dimensional view of the inside of the colon and rectum that can be used to identify polyps or cancer. Another method is the fecal immunochemical test (FIT), which checks stool for tiny amounts of blood given off by polyps or colorectal cancer. Cologuard tests stool for tiny amounts of blood as well as for certain abnormal sections of DNA in cells shed by cancer or polyps that end up in the stool.

In 2014, researchers funded by Cologuard’s maker published in the New England Journal of Medicine results of a study of 10,000 patients comparing three methods of colorectal cancer screening. Screening colonoscopy was better at finding cancer and pre-cancerous polyps than both Cologuard and the FIT test. Cologuard found 93 percent of the cancers detected by screening colonoscopy. That’s a great result, but when we’re talking about cancer, missing 7 percent is a big deal. That means Cologuard could fail to detect colorectal cancer in 1 out of every 13 people who use the test — a significant number considering that more than a million people have used it and many more will likely use it.

Ninety-five percent of colon cancers begin as polyps. Cologuard is not as good at finding pre-cancerous polyps and, unlike colonoscopy, it can’t remove them. According to the NEJM study, Cologuard misses more than 30 percent of polyps that will soon be cancer, and 57 percent of polyps that may become cancer.

I got deeply concerned about this when I read news reports that Exact Sciences stock jumped double digits in May 2018 because new screening guidelines from the American Cancer Society potentially increased the market for Cologuard by 20 million Americans when it lowered the minimum age for colorectal screening from age 50 to age 45.

Don’t get me wrong. Cologuard is a good screening test. In fact, I was one of the physicians who provided patient data for its initial validation study. The Multi-Society Task Force on Colorectal Cancer recommends Cologuard as an acceptable second-line screening option. The task force concluded that physicians should recommend colonoscopy first. For patients who decline to have one, the FIT test should be offered next, followed by second-tier tests such as Cologuard and CT colonography for patients who decline both of the first-line options.

Some people should not be prescribed Cologuard at all. It is not approved for individuals at high risk of colorectal cancer, including those with conditions that increase the risk, such as a personal history of polyps, inflammatory bowel disease, chronic ulcerative colitis, Crohn’s disease, or familial adenomatous polyposis; or a family history of colorectal cancer or polyps.

The task force ranked colonoscopy in the top tier of screening tests because it is the only test that not only detects colorectal cancer but also prevents it by removing polyps during the procedure. It is the only test that is appropriate for people who have risk factors such as a personal or family history of colorectal cancer or polyps.

Almost 1 in 6 people who use the Cologuard test will have a positive result that suggests the presence of colorectal cancer. They will no doubt worry they have colon cancer while scheduling and preparing for the recommended follow-up colonoscopy. For almost half of them (45 percent), the colonoscopy will show they do not have cancer.

Individuals with a positive Cologuard test who are covered by Medicare may face a costly bill because insurance covers 100 percent of the cost of colonoscopy as a preventive screening test, but a follow-up colonoscopy for a positive Cologuard is considered a diagnostic or therapeutic service and may not be fully covered.

Colorectal cancer is the second leading cause of cancer death in the United States, behind lung cancer, but the survival rate is very high if it is found early. Preventing cancer is even better than finding it early. If our goal is to prevent colorectal cancer, then finding, quantifying, localizing, and removing polyps is the most effective strategy.

Every time I diagnose colorectal cancer, I feel like the system has failed.

Some day we may have a simple blood, saliva, or stool test that can detect colorectal cancer and polyps better than colonoscopy. There may even be medications to remove the cancer or dissolve polyps. When that day arrives, I will prescribe that new screening test because the science is sound and it is in the best interest of my patients. Until then, I will counsel physicians and their patients to choose science over convenience. That choice should be screening colonoscopy, the only test that can both detect and prevent colorectal cancer.

Naresh Gunaratnam, M.D., is a gastroenterologist and research director at Huron Gastroenterology in Ypsilanti, Michigan; chief medical officer of Lean Medical Technologies; and a speaker for Medtronic about esophageal cancer.

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  • I used cologuard.
    Totally useless.
    Cologuard test results low risk.
    Had a fit positive fit test a year later.
    Colonoscopy revealed 25 mm flat polyp.
    Cologaurd 695 dollars that might give a false sense of security while you get cancer.
    Should be taken off the market.

    • I agree 100% that it should be taken off the market. Don’t know if you sae my comment or not but I had a false positive so I HAD to get a colonoscopy. Insurance considered the colonoscopy ‘diagnostic’ and not screening. Still making payments on that. My doctor said that Cologuard ‘will get away with it for it as long as they can.’ I will pontificate against Cologuard to anyone who will listen and have discouraged numerous people from using it and getting the colonoscopy instead.

  • Human dignity and quality of life trumps science. It will be another 50 years before modern medicine is truly modern, effective, dignified and humane. Right now, medical treatment is too often medieval. Especially anything that involves the colon or prostate. After researching the subject of cancer, cancer treatment?, and cancer screening, I’ve decided to refuse any more screening. I accept my mortality, and will not trade my physical and mental well-being, or my quality of life, in exchange for the false promise of life extension. No amount of cancer fear mongering will change my mind, and cancer treatment is very much a fear-based business. A 200 billion dollar business. This has created a serious financial conflict of interest between doctors and patients. Medical treatment in total exceeds 3 trillion each year. The disease treatment business is very big business that preys on every American man, woman and child. The Medical Industrial Complex is three times bigger than the Military Industrial Complex. Will you or someone close to you be its next victim?

  • Reply to Archie’s Oct 25 post to me –

    Archie – you compared your desire for an all-male surgical team to a woman’s preference for a female OB-GYN.

    In my first reply to you, I discussed abuse of women vs abuse of men in addition to staffing problems.

    I thought that my mention of staffing problems was sufficient, but I guess it wasnt’. So here it is in detail.

    I pointed out that your statement was not an apples to apples comparison b/c requesting that your attending doc be of a certain sex is not at all the same as requesting an entire surgical team to be of one sex. Your request would involve a lot of rescheduling of a lot of people, and so no, it’s not at all the same.

    If you are super rich and can pay cash for everything, you can probably get whatever you want. Otherwise you can’t. None of can. None of us do. And so we have to deal with reality, whether we like it or not. And I’m sure all of us have faced horrible problems with our healthcare system which we can’t avoid b/c we’re not super rich.

    And I mean horrible problems which may endanger our lives — like having our docs not pay attention to us b/c they’re in such a hurry, or not having access to care b/c of lack of insurance. Your “horrible problem” does not endanger your life unless you choose for it to by not having a procedure you need.

    Extrapolate your preference to other hetero people and to people who are gay and whatever else they may ID with in terms of gender or sexual preference.

    You can’t expect a hospital or surgi-center to reschedule its entire staff due to each patient’s personal gender preference. The staffing schedule would become impossible.

    Again, your attending doc — like an ob-gyn or urologist or cardiologist is one thing, and you should get to choose.

    (But even then, sometimes you can’t b/c no one is available. I’ve had to see male docs when no women were available. I’ve also had to see docs that arent’ my first or second choice b/c I can’t get an appt with the doc of my choice.)

    But choosing an entire team is a completely different situation. And I would never expect any organization to turn itself upside down for me. Unless I could pay, a LOT, for all the inconvenience. And even then, it simply may not be logistically possible.

    Plus certain docs may have a preferred team that they like to work with and know they work well with, and wouldn’t want to work with other people.

    That’s reality. I’m not saying it’s perfect. Our healthcare system has so many horrible problems that I could go on for hours. We all have to deal with it.

    So, you can choose to avoid the procedure you need or deal with reality.

    You can disagree with me again, but I wont’ respond. I’m trying again to explain what I said, but twice is my limit.

  • But what if the colonoscopy shows no polyps, but, because of a long colon , can’t get the scope all the way to the end. Then, given an attempt at colonography without sedation, the pain was way too much and the colonography had to be abandoned. Then what? That’s what happened to me.

  • Check with your insurance before using a cologuard test. Sure my insurance covered the cologuard test but they also considered the cologuard test a colonoscopy! So when my husband got a positive test result the insurance did not cover the colonoscopy that was now required. One of the few things insurance covers before the giant deductibles – cologuard test managed to fugg it up, and no one will tell you; going to cost me thousands, Thanks!

    • The screening colonoscopy is covered but what about the prep and anesthesia? If your husband was in for a screening colonoscopy and there was any finding, he would wake up with a bill

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