Vasectomy and prostate cancer risk: a meta-analysis of cohort studies.

Some studies have suggested that vasectomy is associated with the increased risk of prostate cancer, however, this conclusion is not supported by all the published studies. In order to examine the relationship between vasectomy and prostate cancer risk, we conducted a meta-analysis of cohort studies to clarify this controversial association. PubMed and Medline were used to identify the cohort studies that reported the association of vasectomy with prostate cancer risk from 1980 to January 2015. Based on a random effects model, the RR and 95% CI were used to assess the combined risk. In total, 10 cohort studies involving more than 7027 cases and 429914 participants were included. There was no significant relationship between vasectomy and prostate cancer risk, the pooled RR (95%CI) was 1.11[0.98, 1.27] (P = 0.109). In subgroup-analysis, the relationship between vasectomy and prostate cancer risk was not significantly modified by the length of follow-up and population distribution except Americans. Omission of any single study had little effect on the pooled risk estimate. Little evidence of publication bias was found. In conclusion, our meta-analysis suggests that vasectomy is not associated with the increased risk of prostate cancer. More studies based on other populations including the Chinese are needed.