The association between vasectomy and prostate cancer:: a systematic review of the literature

Objective: To evaluate the possible association between vasectomy and prostate cancer. Design: Systematic review of the literature. Patient(s): Fourteen original studies published between January 1985 and December 1996 that addressed the association between vasectomy and prostate cancer. Main Outcome Measure(s): The strength of the association was estimated with the use of a meta-analysis (DerSimonian and Laird method). A sensitivity analysis was conducted to assess the impact of different sources of heterogeneity. Result(s): Fourteen original papers were reviewed (5 cohort and 9 case-control studies). Relative risks ranged between 0.44 (95% confidence interval [CI] = 0.1-4.0) and 6.70 (95% CI = 2.1-21.6). The overall relative risk (DerSimonian and Laird estimate) was 1.23 (95% CI = 1.01-1.49). The sensitivity analysis showed that this measure was very sensitive to the study base, the type of design used, and the possibility of bias. Further, the funnel plot demonstrated the probable existence of publication bias. Conclusion(s): No causal association was found between vasectomy and prostate cancer. Individuals who have undergone vasectomy are not at high risk for the development of prostate cancer. (Fertil Steril(R) 1998;70:191-200. (C)1998 by American Society for Reproductive Medicine.).