Risk factors for colorectal cancer in a fecal immunochemical test‐positive group: The National Health Insurance Service‐National Health Screening Cohort

Abstract

AbstractBackground and AimColorectal cancer (CRC) was the fourth most common cancer in Republic of Korea in 2019. It has a gradually increasing mortality rate, indicating the importance of screening for CRC. Among the various CRC screening test, fecal immunochemical test (FIT) is a simple yet most commonly used. Neverthelss, there have been only few long‐term studies on subjects with FIT‐positive. Therefore, in this study, we aimed to investigate the risk factors for CRC in FIT‐positive patients using the National Health Insurance Service Bigdata database.MethodsAmong 1 737 633 individuals with a FIT screening result for CRC in 2009, 101 143 (5.82%) were confirmed to be FIT positive. The CRC incidence over 10 years (up to 2018) of these participants was investigated using the National Cancer Registry.ResultsOut of the 101 143 FIT‐positive participants, 4395 (4.35%) were diagnosed with CRC. The FIT‐positive patients who underwent a second round of screening showed a 5‐year cumulative CRC incidence of approximately 1.25%, whereas those who did not showed an incidence of approximately 3.75%. Among the FIT‐positive patients, the CRC incidence in the non‐compliance group for the second round of screening was 2.8 times higher than that in the compliance group.ConclusionsIn FIT‐positive participants, non‐compliance with the second round of screening was identified as a major risk factor for CRC development. It is necessary to establish appropriate strategies for managing risk factors for CRC in FIT‐positive patients to increase the rate of compliance with the second round of CRC screening.