Risk of colon polyps and colorectal cancer in primary biliary cholangitis, a population-based retrospective cohort study in Taiwan.

[BACKGROUND & AIMS] Bile acids are carcinogens causing mutations leading to colorectal cancer (CRC). Higher total bile acid concentrations in the serum of patients with primary biliary cholangitis (PBC), compared to healthy controls, have been reported in previous studies. However, the association between PBC and the risk for CRC remains controversial. We investigated the association between PBC and the development of colonic polyps leading to CRC overall in this study.

[METHODS] The study enrolled 1,936,512 individuals from the Longitudinal Health Insurance Database spanning 2000 to 2017 for cohort analysis. Individuals assigned to ICD-9-CM and ICD-10-CM codes representing PBC were incorporated. A 1:4 control cohort was randomly selected. After adjusting for CRC risk factors using Cox regression analysis, we calculated the hazard ratios for developing colon polyps and CRC in PBC patients compared to the general population.

[RESULTS] Within the study cohort, consisting of 2024 individuals meeting the inclusion criteria, 199 patients developed colon polyps or CRC. In contrast, among the 8096 individuals in the comparison cohort, 650 cases of colon polyps or CRC were observed during the 17-year-follow-up period. According to Cox regression analysis, the adjusted hazard ratio indicated that the risk was 1.678 times higher in the PBC group compared to the comparison group.

[CONCLUSION] This population-based retrospective cohort study identified a 1.68-fold increased risk of colon polyps and CRC in patients with PBC, suggesting a potential association with colonic neoplasia. Further research is warranted to evaluate the role of endoscopic surveillance in patients with PBC.