Risk for Colorectal Cancer in Patients with Serially Positive Fecal Immunochemistry Test in an Annual Screening Program.

OBJECTIVES: There are patients who do not undergo colonoscopy even if the fecal immunochemistry test (FIT) results are positive and even with repeated positive test results the following year. We aimed to investigate colorectal cancer (CRC) risk in examinees with positive FIT results in our annual screening program. METHODS: We analyzed patients who underwent initial colonoscopy from April 2010 to March 2017 because of positive FIT results using an endoscopy database in our hospital. We investigated the difference in the risk of advanced colorectal neoplasia as a surrogate marker of CRC between those who had an initial positive test and those who had repeated positive tests. RESULTS: A total of 748 patients were included in this analysis. The advanced neoplasia detection rates were 7.6% (50/656) and 18.5% (17/92) for the initial and repeated positive test groups, respectively. Subgroup analysis of those with repeated positive tests revealed that the detection rates in examinees with positive tests 1-2 and >2 years ago were 16.7% (6/36) and 19.6% (11/56), respectively. The odds ratios for advanced neoplasia detection in patients with positive tests 1-2 and >2 years ago compared with those in the initial positive test group were 2.72 (95% confidence interval [CI], 1.04-7.10) and 3.09 (95% CI, 1.47-6.48), respectively. CONCLUSIONS: The risk of CRC appears more than doubled in patients with a repeated positive FIT result. Prompt colonoscopy is recommended for FIT-positive cases.