At-Home Stool Test for Colon Cancer
Review of 19 studies found the exam spotted the disease about 79 percent of the time
By Amy Norton
MONDAY, Feb. 3, 2014 (HealthDay News) -- A newer type of test that looks for hidden blood in the stool is an effective way to screen for colon cancer, a research review suggests.
The tests, called fecal immunochemical tests (FITs), are done at home and detect tiny amounts of blood in the stool -- a possible sign of colon cancer. In the new review, researchers found that across 19 studies, FITs caught more than three-quarters of colon tumors, and were very good at ruling out the cancer.
Experts said the findings give "reassurance" that an already commonly used test performs well.
"FIT testing continues to have very good potential as a screening tool," said Dr. Elizabeth Liles, of the Kaiser Permanente Center for Health Research in Portland, Ore.
Liles and her colleagues reported their findings in the Feb. 4 issue of the journal Annals of Internal Medicine.
Experts currently recommend that people at average risk of colon cancer start getting screened at age 50. And they can choose from several options, including yearly stool tests followed by a colonoscopy if the result is positive, a colonoscopy done every 10 years or sigmoidoscopy every five years. Colonoscopy and sigmoidoscopy are both invasive procedures that inspect the interior of the colon, but sigmoidoscopy is less thorough -- looking only at the lower portion of the colon.
In recent years, more doctors have been using FITs instead of the traditional fecal occult blood test, because they're better at picking up cancer and they're easier for people to use.
Still, individual studies have had a fairly wide range of findings on the FIT tests' sensitivity -- that is, their likelihood of giving a positive result when a person has colon cancer.
The new study gives a clearer idea of how the tests perform on average, according to a colon cancer expert who was not involved in the research.
"It gives some very valuable information," said Dr. Andrew Chan, a gastroenterologist at Massachusetts General Hospital in Boston.
But there are still bigger questions, Chan said. Experts still don't know which screening test is most effective at preventing deaths from colon cancer.
Colonoscopy is widely considered the "gold standard" for screening, because it allows the doctor to visually inspect the interior of the colon -- and, if necessary, remove precancerous growths called polyps.
Chan said it's not yet clear how FIT and colonoscopy compare when it comes to cutting people's risk of dying from colon cancer.
There are studies under way, though. A large U.S. government trial is randomly assigning people to have either a colonoscopy or an annual FIT screening, then following their rates of death from colon cancer over 10 years. (In the United States, colonoscopy is the most common screening method, followed by stool testing. Few doctors perform sigmoidoscopy.)