The association between inflammatory bowel disease and risk of prostate cancer: a population-based retrospective study based on Korean National Health Insurance Service database

To determine whether inflammatory bowel disease (IBD) is associated with the risk of developing prostate cancer (PCa) through a population-based study. Male patients aged ≥40 years, diagnosed with IBD from 2010 to 2013 and without IBD were identified and followed up to 2019. A 1:4 matched cohort of male patients with and without IBD was created, based on age, income level and Charlson comorbidity index. Multivariate Cox regression analysis was conducted to evaluate the association of IBD with the prescence of PCa and PCa requiring definitive treatment within 1 year of diagnosis. The hazard ratio (HR) and 95% confidence interval (CI) were stratified by Crohn's disease (CD), ulcerative colitis (UC) and subtypes. After matching, 15,751 IBD patients and 62,346 controls were analyzed. Over a median follow-up period of 96 months, the HR for PCa was significantly increased in patients with IBD (HR, 2.44; 95% CI, 2.08-2.86, p < 0.001). IBD was also associated with PCa requiring definifive treatment within 1 year (HR, 2.67; 95% CI, 2.09-3.42, p < 0.001). In subgroup analysis, UC (HR, 2.83; 95% CI, 2.18-3.69, p < 0.001) showed higher risk of PCa requiring definifive treatment than CD (HR, 2.21; 95% CI, 1.43-3.43, p = 0.0004). All-cause death in patient diagnosed PCa was highest in UC of pancolitis (HR, 2.26; 95% CI, 0.99-5.16, p = 0.054), and lowest in ulcerative proctitis (HR, 0.35; 95% CI, 0.21-0.60, p = 0.0001). IBD was associated with an increased incidence of PCa in our matched analysis.