At-Home Stool Test for Colon Cancer
Review of 19 studies found the exam spotted the disease about 79 percent of the time
For the new review, Liles and her colleagues analyzed 19 studies done since 1996, looking at eight different brands of FIT tests. They found that the tests' sensitivity did vary from study to study, but the discrepancy narrowed when the researchers excluded tests that are no longer on the market.
On average, the review found that FITs catch about 79 percent of colon cancers, and their specificity consistently tops 90 percent. That means the tests accurately give a negative result to more than 90 percent of people who do not have colon cancer.
One surprise, Liles said, was that FITs that require two or three stool samples performed no better than single-sample tests. That matters, she said, because people might be more willing to do the test if it's simpler.
FIT screening is already fairly easy. Like older stool tests, they're done with a take-home kit: You use a brush to get a stool sample, and then mail it to a lab. But unlike older tests, FITs don't require any diet or medication restrictions in the days before the test.
The simplicity of the stool test is an obvious advantage over colonoscopy screening, Liles said. But she agreed that more research is needed to know which screening test is more effective at saving lives.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases and the National Cancer Institute provided much of the funding for the review.
So which exam should you choose? "That decision is between you and your doctor," Chan said. What matters most, he added, is that "some form of screening is done."
Liles agreed. "It's said that the best screening test is the one that you'll actually get done," she said.
In the United States, the average lifetime risk of colon cancer is about one in 20, according to the American Cancer Society. In each of the past several years, more than 50,000 Americans have died of the disease -- but the death rate has been declining for a couple decades, partly because of screening, the cancer society said.
Still, many people aren't getting screened, Liles said.
In November, a federal report said that more than one-third of Americans aged 50 to 75 were not up to date with their colon cancer screening. That included 28 percent who had never had any type of screening test.