Patients who test positive on a fecal immunochemical test (FIT), even after a recent colonoscopy, should be offered a repeat colonoscopy. That is the conclusion following a review of 2,228 subjects who were FIT positive, which revealed a greater risk of colorectal cancer (CRC) and advanced colorectal neoplasia (ACRN) the longer the gap since the last colonoscopy. The findings support the recommendations of the U.S. Multi-Society Task Force on CRC Screening to offer repeat colonoscopies to FIT-positive patients, even if they recently underwent a colonoscopy.
That recommendation was based on low-quality supporting evidence, and there is currently little agreement about whether annual FIT should be performed along with colonoscopy.
The researchers set out to detect the frequency of CRC and ACRN among patients with a positive FIT test. They analyzed data from the National Cancer Screening Program in Korea, which offers an annual FIT for adults aged 50 years and older as an initial screening, followed by a colonoscopy in case of a positive result.
The researchers analyzed data from 52,376 individuals who underwent FIT at a single center in Korea during January 2013–July 2017. They excluded patients with a history of CRC or colorectal surgery, inflammatory bowel disease, or poor bowel preparation.
FIT-positive and FIT-negative patients were divided into three groups based on the length of time since their last colonoscopy: less than 3 years, 3-10 years, or more than 10 years or no colonoscopy.
Compared with FIT-negative subjects, FIT-positive individuals were more likely to be diagnosed with any colorectal neoplasia (61.3% vs. 51.8%; P less than .001), ACRN (20.0% vs. 10.3%; P less than .001), and CRC (5.0% vs. 1.9%; P less than .001).
A total of 6% of subjects had a positive FIT result, and data from 2,228 were analyzed after exclusions. They were compared with 6,135 participants who had negative FIT results but underwent a colonoscopy.
Of patients with a positive FIT result, 23.1% had a colonoscopy less than 3 years before, 19.2% had one 3-10 years prior, and 57.8% had a colonoscopy more than 10 years earlier or had never had one.
The more-than-10-year group had a higher frequency of colorectal neoplasia, ACRN, or CRC (26.0%) than did the 3-10-year group (12.6%), and the less-than-3-year group (10.9%; P less than .001 for all). A similar trend was seen for CRC: 7.2%, 1.6%, and 2.1%, respectively (P less than .001).