Insights Into Colorectal Cancer Screening: A Multidatabase Cohort Study of Over 1.5 Million Taiwanese.

ABSTRACT

INTRODUCTION: Colorectal cancer (CRC) remains a significant public health concern. This study aims to provide a comprehensive understanding of the effectiveness of fecal immunochemical test (FIT) screening on CRC incidence and mortality, leveraging the scale of over 1.5 million randomly selected Taiwanese and more than 11.7 million person-years of follow-up. METHODS: This prospective cohort study merges data from 3 robust Taiwanese health databases the CRC screening program, cancer registration, and death registration databases. Incidence and mortality rates of CRC were calculated based on age, sex, urbanization, and past screening status. Cox proportional hazard models were used to assess the association between screening statuses and CRC incidence or mortality, adjusting for age, sex, and urbanization levels. Statistical analysis of the data was conducted in 2021-2022. RESULTS: FIT screening was associated with a 33% reduction in CRC incidence and a 47% reduction in mortality. The study identified a dose-response relationship between the fecal hemoglobin concentration (f-HbC) levels and CRC risk. Participants with consistent FIT-negative results had significantly reduced CRC incidence and mortality risks, while those with one or more positive FIT results faced increased risks. Notably, compliance with follow-up examinations after a positive FIT significantly lowered mortality risk. CONCLUSIONS: This large-scale study validates the efficacy of FIT screening in reducing CRC incidence and mortality. It offers a nuanced understanding of how various screening statuses impact CRC risks, thus providing valuable insights for public health strategies aimed at CRC prevention.