Tests that require patients to collect a single stool sample at home and then send it to a lab for analysis will detect about 79 percent of colorectal cancers, according to a new evidence review published in the Annals of Internal Medicine. The review of 19 studies examining eight different fecal immunochemical tests, known as "FITs," also finds that the tests will correctly identify about 94 percent of patients who do not have cancers of the rectum or colon.
"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. "The American Cancer Society and other professional organizations have recommended FIT as a screening tool for colorectal cancer since 2008, but there are still many people who don't know about it."
The U.S. Preventive Services Task Force recommends that people with normal risk for colorectal cancer should begin screening at age 50 and stop at age 75. Unlike older stool tests, FIT does not require people to restrict their diets or to stop taking medications. 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. People who have a positive FIT need a follow-up colonoscopy to look for cancer or pre-cancerous polyps.
Other screening options for colorectal cancer include sigmoidoscopy, which involves physical examination of the lower colon, recommended every five years; or colonoscopy, which examines the entire colon, every 10 years.