Risk Stratification Using the Asia-Pacific Colorectal Screening Score in Asymptomatic and Fecal Immunochemical Test-Positive Individuals in Japan.

BACKGROUND: Currently, most colorectal cancer (CRC) screening programs, such as fecal immunochemical test (FIT)-based, adopt a one-size-fits-all approach; however, the limited colonoscopy capacity necessitates risk stratification in CRC screening. In this study, we evaluated whether the Asia-Pacific Colorectal Screening (APCS) score can be applied for risk stratification in both asymptomatic individuals undergoing screening colonoscopy and those with a positive FIT in Japan. METHODS: We retrospectively analyzed individuals aged ≥40 years who underwent their first colonoscopy between January 2015 and April 2025. Individuals were classified into average-, moderate-, and high-risk groups according to their APCS scores. The detection rates of advanced colorectal neoplasia (ACN) and the area under the receiver operating characteristic curve (AUROC) of the score for ACN detection were evaluated separately in asymptomatic individuals undergoing screening colonoscopy and those with a positive FIT. RESULTS: A total of 1366 asymptomatic individuals were included. In the 825 individuals undergoing screening colonoscopy, ACN detection rates increased across APCS risk categories (average: 1.6%, moderate: 6.7%, high: 16.0%; p<0.001). In the 541 FIT-positive individuals, ACN detection rates also increased across APCS risk categories (average: 7.1%, moderate: 17.8%, high: 28.8%; p<0.001). The AUROC of the score for ACN detection was 0.68 and 0.63 in individuals undergoing screening colonoscopy and FIT-positive individuals, respectively. CONCLUSIONS: Risk stratification was demonstrated using the APCS score in asymptomatic Japanese individuals undergoing screening colonoscopy and in FIT-positive individuals, supporting the potential for more efficient use of limited colonoscopy capacity.