According to the new evidence,, the review of 19 studies in the Annals of Internal Medicine examined eight different fecal immunochemical tests, know as "FITs."
"We know the FIT is easy to use, and now we also know that it is a great tool for assessing which patients have cancer and which patients don't," said Beth Liles, MD, review co-author and clinical investigator at the Kaiser Permanente Center for Health Research in Portland, Ore.
Colorectal cancer is the second leading cause of cancer death in the United States, according to the Centers for Disease Control and Prevention. Yet one in three adults is not adequately screened.
"FIT is simple, can be done at home, and can save lives," said Jeffrey Lee, MD, MAS, the study's lead author and post-doctoral researcher at the Kaiser Permanente Division of Research in Oakland, Calif. and University of California, San Francisco.
Conducted annually, the test detects small amounts of blood in the stool, and people who test positive are much more likely to have colorectal cancer.
Other screening options for colorectal cancer include sigmoidoscopy, which involves physical examination of the lower colon, or colonoscopy, which examines the entire colon. The risks of either method exceed the benefits.
Even though current guidelines advocate colorectal cancer screenings for those with severe illnesses, they may bring little benefit and may actually pose harm. R. Scott Braithwaite, M.D., and his colleagues developed a new method of evaluating medical screening tests like colonoscopy, called the "payoff time," which is the minimum amount of time it takes for the benefits from a test to exceed its harms (i.e., its complications and side effects).
The evidence review, funded by the National Institutes of Health, found that the FITs were fairly sensitive. On average, the tests detected 79 percent, or about 4 of 5 cancers with only one round of testing. The tests were also highly specific: on average, 94 percent of people who did not have cancer tested negative with a single FIT.
By comparison, studies indicate that another at-home test called fecal occult blood test (also known as FOBT) detects only about 13 to 50 percent of cancers after a single round of testing. The FOBT is the predecessor to FIT and requires three stool samples as well as medication and dietary restrictions.
The key is to avoid invasiive conventional medical screening
such as colonoscopy and focus on natual dietary methods of prevention.