When used in a large health care system, the fecal immunochemical test (FIT) was sensitive for detecting colorectal cancer and adherence to recommended annual follow-up testing was high, making the non-invasive stool test a feasible and effective screening tool, according to a Kaiser Permanente study published today in Annals of Internal Medicine.
Unlike older stool tests, FIT does not require any dietary or medication restrictions and can be completed entirely by mail. The test detects small amounts of blood in the stool, finding most colorectal cancers before there are any symptoms.
“FIT has the benefit of being done every year, so we can detect cancers that start growing in-between tests,” said Douglas A. Corley, MD, PhD, Kaiser Permanente gastroenterologists and an author of the study.
“The vast majority of Kaiser Permanente members who chose FIT for colorectal cancer screening were willing to continue taking the test year after year,” said Pauline A. Mysliwiec, MD, a Kaiser Permanente gastroenterologist and study co-author. “Since FIT detected cancers at an early stage, patients will have excellent long-term outcomes.”
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.
The U.S. Preventive Services Task Force recommends that people at average risk be screened for colorectal cancer between ages 50 and 75. Other recommended screening tests are colonoscopy, which examines the entire colon with a flexible camera, every 10 years; and sigmoidoscopy, which examines the lower colon, every five years.
The current screening rate for colorectal cancer in Kaiser Permanente — a large, integrated, health care system — is currently over 80 percent. All screening methods are available to Kaiser Permanente members, although the most commonly used ones are FIT and colonoscopy.
In the study published in Annals of Internal Medicine, about 670,000 FIT kits were mailed to eligible members of Kaiser Permanente’s Northern and Southern California regions between 2007 and 2013. More than 323,000 members completed a fecal test in the first year.
FIT detected 80.4 percent of patients with colorectal cancer in the first year, and 73.4 to 78 percent in the subsequent three years of screening. Furthermore, more than 75 percent of people who started screening with FIT repeated the screening test. Of those whose FIT tests were positive, almost 80 percent completed the recommended follow up colonoscopy within a year and 97 percent had a colonoscopy or other follow-up.
“We don’t have evidence that one colorectal cancer screening test is better than another; each has its advantages and disadvantages. The most important thing is that people get screened,” said Theodore R. Levin, MD, Kaiser Permanente gastroenterologist and a study co-author. “FIT can be done at home, and it doesn’t require bowel preparation or a visit to the doctor’s office. Colonoscopy is also an excellent test, but not everyone is willing to have an invasive test just for screening.”