Association between nonalcoholic fatty liver disease and colorectal cancer: A population-based study

Colorectal cancer (CRC) and nonalcoholic fatty liver disease (NAFLD) have high prevalence rates and place a considerable burden on the health-care industry. The association between both diseases is controversial. Our aim was to examine the association between NAFLD and CRC. Using data extracted from the Taiwan National Health Insurance Research Database (NHIRD) from 2000 to 2015, we enrolled 60 298 patients with NAFLD. Of these, 52,986 met the inclusion criteria. A comparison group was selected using 4-fold propensity score matching by age, sex, and year of index date. The primary outcome was the cumulative incidence of CRC in patients with NAFLD. Over a mean follow-up period of 8.5 years, 160 new cases of CRC were identified. The incidence rate of CRC was higher in the NAFLD group (12.23 per 100,000 person-years) than in the comparison cohort (6.0 per 100,000 person-years). Cox proportional hazards regression analysis revealed that the adjusted hazard ratio (HR) of CRC was 1.259 in the study group (95% confidence interval [CI]: 1.047–1.486, P = .003). Using Kaplan–Meier analysis, we ascertained that the cumulative incidence of CRC was significantly high in the NAFLD group. Patients older than 50 years, with diabetes mellitus (DM), and with chronic liver disease also exhibited a high risk of CRC. NAFLD was associated with a high risk of CRC. CRC occurs more frequently in patients with NAFLD aged between 50 and 59 years and those older than 60 years with comorbidities, including DM and chronic liver disease. Physicians should consider the subsequent risk of CRC when treating patients with NAFLD.