Association between inflammatory bowel disease and risk of incident prostate cancer: a systematic review and meta-analysis of cohort studies.

BACKGROUND AND OBJECTIVE: Numerous observational studies have been conducted to investigate the potential association between inflammatory bowel disease (IBD) and prostate cancer (PCa). However, a definitive conclusion has yet to be established. We therefore performed a meta-analysis to explore the relationship between these two conditions. METHODS: PubMed, Embase, and Web of Science databases were systematically searched to identify all relevant cohort studies that investigated the association between IBD and risk of incident PCa published from inception to February 2023. The pooled hazard ratios (HRs) with 95% confidence intervals (CI) was calculated as effect size for the outcome based on random-effects model meta-analysis. RESULTS: A total of 18 cohort studies with 592,853 participants were included. The meta-analysis revealed that IBD was linked to an elevated risk of incident PCa (HR = 1.20, 95% CI: 1.06-1.37, P = 0.004). Further subgroup analyses revealed that ulcerative colitis (UC) was linked to an increased risk of incident PCa (HR = 1.20, 95% CI: 1.06-1.38, P = 0.006), while Crohn's disease (CD) is not significantly associated with a higher risk of PCa (HR = 1.03, 95% CI: 0.91-1.17, P = 0.65). There was a significant correlation between IBD and an elevated risk of incident PCa in the European population, but such a correlation was not observed in the Asian and North American populations. Sensitivity analyses indicated that our results were robust. CONCLUSIONS: Our latest evidence indicates that IBD was linked to an elevated risk of incident PCa, especially in UC patients and the European population.