Hypertension and risk of prostate cancer: a systematic review and meta-analysis

The previously reported association between hypertension and prostate cancer risk was controversial. We performed this systematic review and meta-analysis of all available studies to summarize evidence on this association. Studies were identified by searching PubMed, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases through January 2016. Pooled relative risks (RRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. A total of 21 published studies were included in this meta-analysis. A significant increase in the risk of prostate cancer (RR 1.08, 95% CI 1.02-1.15, P = 0.014) was observed among individuals with hypertension. There was statistically significant heterogeneity among included studies (P < 0.001 for heterogeneity, I(2) = 72.1%). No obvious evidence of significant publication bias was detected by either Begg's test (P = 0.174) or Egger's test (P = 0.277). In conclusion, this meta-analysis indicates that hypertension may be associated with an increased risk of prostate cancer. Considering the substantial heterogeneity and residual confounding among included studies, further large-scale, well-designed prospective cohorts, as well as mechanistic studies, are urgently needed to confirm our preliminary findings.