FOR PEOPLE AT AVERAGE RISK of developing colorectal cancer, at-home screening tests are convenient alternatives to a more thorough but more invasive colonoscopy. Options for at-home screening include fecal immunochemical tests, known as FIT, and the multitarget stool DNA test, better known under the trade name Cologuard. The choice between these tests was the subject of recent research because, while both tests have proven to be equally effective at detecting signs of colorectal cancer, Cologuard is significantly more expensive.

According to U.S. Preventive Services Task Force guidelines, most people should begin screening for colorectal cancer between the ages of 45 and 50. Those willing to prepare for and undergo a colonoscopy can wait 10 years after a negative result before following up with another screening. FIT and Cologuard are noninvasive tests of stool samples that people can take at home, but they require more frequent follow-ups, with screenings at least every three years for Cologuard and annually for FIT.

Research presented at the American College of Surgeons Clinical Congress 2022 in October found that patients within the Allegheny Health Network in Pittsburgh who elected to use noninvasive screening instead of getting a colonoscopy were prescribed Cologuard slightly more often than FIT tests, according to Pavan Rao, a general surgery resident within the health system who presented the study results. The research also determined that if all the noninvasive colorectal cancer screening in the study had been directed to FIT testing from the more expensive Cologuard, the cost of testing would have been reduced by $3.9 million.

“Our health system has started looking at counseling providers on using FIT testing primarily,” Rao says.

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Rao and his colleagues examined insurance claims data for 117,519 patients using Highmark, a private insurance provider that partners with the Allegheny Health Network. Of those, 91,297 were screened using either FIT or Cologuard, with about 38.7% using FIT and 39.2% using Cologuard.

There was little difference in outcomes. For patients diagnosed after testing with FIT, 59.5% were diagnosed with cancer stages 0 through II. Patients tested using Cologuard were diagnosed with these cancers 62.3% of the time.

Despite the similarities in performance, there is a substantial difference in cost. The researchers used Medicare reimbursement rates to estimate that FIT tests run in this study cost around $24 per test, while the Cologuard tests cost around $121 per test. Rao emphasizes that these are estimates but that they are likely underestimates. The cost to private insurers like Highmark tends to be higher, but Rao says Highmark would not disclose that data for the study.

Choosing the Right Screening Test

Colonoscopy and at-home screenings each offer benefits and drawbacks. Which you should get depends on your preferences and risk profile.

The cost of colorectal screening tests can be a real problem for health systems and for those trying to make the best use of noninvasive screening tests, says Julius Wilder, a gastroenterologist at Duke Health in Durham, North Carolina, who studies health disparities.

Wilder was not involved in the Allegheny study, but he notes that tests like FIT and Cologuard can provide cancer screening options for people who lack financial or geographic access to colonoscopies.

“But if you’re going to leverage these noninvasive tests because they’re cheaper than colonoscopy and they can be done at home, you’re going to want to leverage the one that gives you a good, reliable result and costs the least,” he says.

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This is especially true because a positive test result using either FIT or Cologuard automatically results in a follow-up colonoscopy, “So if you can minimize those costs on the front end, that can be extremely helpful,” Wilder adds.

At the same time, Rao notes that his research has limitations. For example, it doesn’t take into account instances where Cologuard might be the better test for some patients based on their particular genetics. While both Cologuard and FIT measure the quantity of blood in stool, a possible sign of colorectal cancer, Cologuard also looks at DNA mutations associated with cancer found in cells shed by the lining of the colon. Both Rao and Wilder say more research is necessary to learn for certain how the two tests stack up. In the meantime, however, research has made clear that for most average-risk people, FIT testing is just as effective as Cologuard at a fraction of the cost. And for people who have more or higher risk factors for developing colorectal cancer, Rao says getting a colonoscopy upfront is probably the best testing option.

Jon Kelvey is a freelance writer covering health and science. He lives in Maryland.