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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.

  • Reply to Lynn’s comment that she was embarrassed b/c the Cologuard logo was on the box so that other people would know its contents —

    It would never occur to me to feel embarrassed. It’s a serious medical test. No different than any other. I think it’s important for those handling it to know that there is bio-material inside. I hope that you will be able to reconsider your feeling about this. There simply is nothing to be embarrassed about.

    And I’ll bet that people in all other countries would not be so squeamish. America has become so superficial in so many ways. It’s not how you feel; it’s how you look. In fact, I’ve had, among tons of other medical problems, intractable chronic pain for over a decade. I feel horrible, and frequently can’t stand up straight. I haven’t had any exercise at all in all these years; my muscles are like jelly. But, I’m thin — and so often get told how great I look. No one is looking at the pain in my face or noticing that I have absolutely no muscle tone.

    And, yes, it’s advertising, but these days, there’s advertising everywhere — sadly, even in schools.

  • I am refusing ALL colorectal cancer screening. I was considering an unsedated colonoscopy, but I can NOT find a provider that would offer me an all male care team. I have even been ridiculed for the suggestion. (Imagine if a woman was ridiculed for wanting a female gynecologist…)

    It is my right to choose who I grant bodily access to. Just because you have been desensitized to the whole process does NOT mean that I am. Then to belittle me for exercising my rights. This is precisely why society has lost ALL trust in the profession of medicine.


    I am refusing Cologuard and all other noninvasive testing as well. I am doing it for the same reason that I have refused all prostate cancer screening: the results will be distracting to my physician.

    I have ADHD and that is the ONLY thing I seek treatment for. My physician feels like is protecting me by slipping cholesterol tests with the mandated liver tests I need for my treatment. He does take care of me when I have a sore throat and need antibiotics.

    I do not want him to focus on cancer screening results, so I just do NOT do cancer screening.

    I do not need a lecture either about the benefits of screening. It is a choice and I choose NOT to screen.


    This is also part of the whole problem with screening; the fact that most people cannot accept the choice NOT to screen as a valid option. This shows a complete lack of respect for the human dignity of patients and that PATERNALISM is alive and well in the profession of medicine.

    What really needs to happen is the profession needs to earn the trust of patients AGAIN (this is not going to happen overnight). This will only be done by allowing patients to have COMPLETE control over their healthcare by offering them all choices (including refusal), RESPECTING those choices, and transparency.

    • Archie — A woman wanting a female GYN is far, far different than a man insisting on an ALL male team for a procedure. I have a female GYN and have had GYN procedures and surgeries, and I’ll bet that men were involved.

      If you pay any attention to the news, the incidents of men abusing female patients is infinitely higher than the other way around. Just like there are zillions more men who visit female prostitutes than the other way around, and sex clubs catering to men, and all the rest.

      The odds of a woman getting her jollies from seeing a naked man are simply teeny tiny compared to the other way around.

      Your’e certainly entitled to your views, and to select male doctors. But, any hospital or outpatient surgi-center has its staff that will be its staff, male or female, and I dont’ imagine that any patient gets to pick an all one-sex team.

    • Cindy,

      So because I am a male I am not allowed a preference?

      It is NOT about being abused, it is about MY choices. You choose to allow men during your surgery, my choice is gender concurrent care.

      Either EVERYONE’S choices are respected or NO ONE’S choices will be respected.

  • Colonoscopy does not find 100% of polyps or cancer. That was conveniently left out.
    A virtual colonoscopy in many states is 1/5th the cost of the “ gold standard”. Maybe Drs should lower their costs?

  • Seems like a lot of confusion could be avoided by separating the blood test from the DNA test and including that fact in the results. Can somebody telle why? It’s basically two different test for two potentially different results (blood in still vs DNA) and that fact probably causes the side array of fake positives. The false negatives and the resulting insurance issues from a down line colonoscopy need to be disclosed. FDA asleep at the wheel. Again.

    • EXACTLY! I would like to know why also. When I learned that these test results were not detailed and only rubber-stamped ‘positive’ or ‘negative’ I was as mad as a hornet; and the fact that I’m facing nearly a grand for a colonoscopy makes me doubly mad. When my primary care dr and I discussed this several weeks ago he said that Cologuard would “get away with it for as long as they can.” Yes….follow the little dancing box right into your bank account.

    • All of these questions can be answered by calling Exact Sciences and asking the reps or a for a supervisor. The website clearly states Exact Sciences does not verify coverage and will help you verify coverage if you call them. Doctors need to be educating patients or be more educated themselves before ordering the product, which is not billed until the test is completed. If you do not do the test (even if you receive it) you will not be billed. Also the test does detect precancerous lesions BETTER THAN ANY OTHER SCREENING TEST. The stats or on the site. It’s not as a good as a colonoscopy but for ALOT of people it’s too invasive or they cannot be put under or will simple not have a colonoscopy, Exact Sciences will never say it replaces a colonoscopy but is an alternative just like a FIT test (which is much less accurate and also can have false positives)

      The test will only give positive or negative because it is a SCREENING, NOT A DIAGNOSTIC TEST. FDA does not allow Exact Sciences to what caused positive result (Blood or DNA) the test is not for everyone and doctors should not be prescribing for certain patients. The Cologuard instructions also list a multitude of reasons people should not do the test. Also likes said a colonoscopy is also considered a screening until something is found then it becomes diagnostic. Just like if you have a positive Cologuard and go have a colonoscopy. This is an insurance and hospital scam. Look it up.

      Cologuard decets 92% of Cancer and 94% of Stage 1&2 Cancer. Also about 40% of precancerous lesions. So a positive result does not mean you have Cancer, actually about a 4% chance you have Cancer after a positive result. About 99% of ppl have a negative result. About 13% of positive are false positives or 1 in 1500 and blood from any source will cause positive result (hemorrhoids, fissure, chapped cheeks, etc). The instructions also lay out these issues and state the test should not be taken if you suffer from any of these. The main false positive is from blood from hemorrhoids, so if Doctor and Patient are doing their due diligence, they would know test should not be taken if you have bleeding hemorrhoids or wait until not bleeding is occurring. Don’t be leave me, call and ask a rep or a supervisor(they will give more thorough info)this the toll free number 1 844-870-8870, they are open 24/7. Scams don’t get FDA approval. They also don’t get the age for patients lowered to 45, 4 years after being brought to market. That is all 🙂

  • Reply to Carol’s reply to Heleb —

    Carol, your post that you had to pay the deductible etc says to me that you have regular Medicare without a Medicare supplement.

    My Supplement pays most such costs.

    So, again, the cost for each person is unique, depending on exactly what Medicare plan they have. And yes, location factors in too I guess.

    • I’m a year away from Medicare. I’m still under my employer’s coverage as a retiree but that will combine with Medicare when I’m eligible. I was just giving the poster an idea of the cost so he could do the math from there. One of my doctors’ wives also had a false positive with Cologuard. He said she called Cologuard and ‘gave them a piece of her mind.’ lol. I doubt it did any good but I’m sure she felt better!

    • I guess your area could determine the cost but mine was $4600. My insur pd for the Cologuard which was false positive by the way. The Cologuard was considered my 10-year ‘screening.’ The colonoscopy was then considered diagnostic—not screening—so I got stuck with the insur deductible and 80% of the remaining balance; those bills should be arriving any day now. So, do your homework and call Medicare if you can’t get answers online. I saw my primary dr this week and he was somewhat annoyed at the whole Cologuard debacle of false positives saying, “they’ll get away with it for as long as they can.” My sentiments exactly. Best of luck to you!

    • Heleb, due to the number of different Medicare plans, I think you need to call Medicare and ask them that question yourself with your own personal info.

      There’s regular Medicare, and people with that may or may not have a Supplement; plus each Supplement is unique. Then there are Medicare Advantage Plans — some are HMO’s and some are PPO’s.

      You need to find out what your costs would be depending on exactly what you have for Medicare.

  • I can’t believe we’re in the 21st century and medical engineering for a lower GI exam is medieval. We can perform CT and MRI scans, but we can’t do anything better than an invasive tedious colonoscopy or shipping our excrement for a questionable diagnosis? Medical engineering should be deeply ashamed.

    • Speaking of shipping our excrement, I was floored that they are allowed to put their logo on the shipping box on two sides. Stood in line at the UPS store trying to cover the logo, it was really embarrassing, I knew that those around me figured out I had poop in that box. We in the medical fields are held to standards of privacy for our patients (HIPPA), the logos should be removed!

  • Many of your colleagues do not agree with your assessment of Cologuard. In fact I have read several opinions of gastro Drs. who say if a person carries no risk factors for colon cancer they themselves recommend the Cologuard test. I am no Dr., but from all I have read there may be a small chance that the Cologuard test could miss something, but that also happens with colonoscopies, plus colonoscopies carry their own risks. I had a bad experience with a colonoscopy myself due to one of the drugs that was administered. You being a Dr. know better than anyone that anesthesia can be very detrimental, but we as patients are learning that also. You guys don’t always tell the whole story when you are advocating for particular procedures for fear that the patient will decline having it done. I didn’t get this from just my own research, I have friends who are Drs. and have been told by them that what I say is true.

  • If the Cologuard mistakes are random, then just do a second test and the probability of missing a true cancer will go down a lot. A third one will virtually eliminate it. The added cost would be well worth it for many who have no desire for a traditional colonoscopy.

    The point here is to get people who will do nothing to do something. Don’t let the perfect be the enemy of the very good.

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