Doubling Up on FIT Testing Catches More Colorectal Cancers

MONDAY, June 12, 2023 (HealthDay News) — A double fecal immunochemical test (FIT) improves sensitivity and cuts the number of missed colorectal cancers, according to a study published online in the April issue of the British Journal of Surgery.

Adam Gerrard, M.B.Ch.B., from the University of Edinburgh in the United Kingdom, and colleagues compared the diagnostic performance of a single FIT versus double FIT in symptomatic populations. The analysis included two sequential prospective patient cohorts (in cohort 1: 2,260 patients completed one FIT; in cohort 2: 3,426 patients completed at least one FIT and 2,637 patients completed both FITs).

The researchers found that the sensitivity of a single FIT was 84.1 percent for colorectal cancer and 67.4 percent for significant bowel pathology. By comparison, a double FIT had a sensitivity of 96.6 percent for colorectal cancer and 83.0 percent for significant bowel pathology. The second FIT reduced by 50.0 percent the cancers missed by the first FIT and resulted in a 30.0 percent reduction of missed significant bowel pathology. There was only a modest association seen with fecal hemoglobin level. For double tests, 16.8 percent were discordant, including 11.4 percent in patients with colorectal cancer and 18.3 percent in those with significant bowel pathology.

“FIT in patients with high-risk symptoms twice in succession reduces missed significant colorectal pathology and has an acceptable workload impact,” the authors write.