The association between inflammatory bowel disease and prostate cancer risk: a meta-analysis

Background Patients with inflammatory bowel disease (IBD) are at increased risk of gastrointestinal and extraintestinal malignancies. However, the associations between IBD and prostate cancer (PCa) risk remain conflicting. Methods We conducted a systematic literature search in PubMed, EMBASE, and Web of Science databases. According to the inclusion and exclusion criteria, a total of nine studies were included in the meta-analysis. The pooled standardized incidence ratios (SIRs) or relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated to determine the relationship of IBD and PCa risk. Results For cohort studies, the pooled SIR was 1.33 (95% CI = 1.03-1.71). The further subgroup analysis showed that the PCa risk was higher in patients with ulcerative colitis (UC) (pooled SIR = 1.58, 95% CI = 1.08-2.30), but not in patients with Crohn's disease (CD) (pooled SIR = 1.12, 95% CI = 0.97-1.31). Besides, for the three case-control studies, the results indicated that compared with normal group, the pooled RR of PCa was 1.81 for the patients with IBD (95% CI = 1.43-2.29). In addition, sensitivity analysis indicated that the results were robust and no significant publication bias were observed. Conclusions Our findings based on the large and multicenter samples strongly indicated that men with IBD especial UC have significantly elevated PCa risk. Future efforts are needed to define the mechanism underlying the link between IBD and PCa or clinically significant PCa risk.