Objective: To determine a survival benefit from colorectal cancer [CRC] screening protocol that uses fecal immunochemical test (FIT) as initial screen, followed by colonoscopy for abnormal results.

Materials and Methods: Between November 2009 and March 2010, we enrolled 9,755 (out of 30,563) residents aged 50 years or older in the Phanomphrai and Nonghi, Roi Et, Thailand for fecal occult
blood test [FOBTs] using FIT. Those with positive results were referred to the colonoscopy service at Roi Et Hospital. We analyzed the end point: CRC death up to 2016.

Results: Of 9,755 tested subjects, 828 (8.5%) had positive FOBT results, of whom 197 had abnormal pre-operative assessments. The remaining 631 were referred to the colonoscopy service, of whom 183 subsequently underwent polypectomy and 10 were found to have colorectal adenocarcinoma. No patients who had positive FIT results and underwent colonoscopy died of CRC, compared with 0.19% among those with negative FIT results, 2.03% among subjects who declined to undergo colonoscopy, and 0.14% for
those who did not enroll in the initial screening program.

Conclusion: Single FIT followed by colonoscopy for positive results can detect early CRC and has a survival benefit as initial colorectal screening.

Keywords: Colorectal cancer screening, Fecal immunochemical test, Fecal occult blood test, Population-based screening