European Cohort Study of Vasectomy and Prostate Cancer Risk
In a large European cohort study reported in the Journal of Clinical Oncology, Smith Byrne et al found that vasectomy was not associated with an increased overall risk of prostate cancer or death from prostate cancer but appeared to increase the risk of lower-grade disease. Other studies have indicated an association, including an increased risk of more aggressive disease.
Study Details
The study involved data from the European Prospective Investigation Into Cancer and Nutrition (EPIC) study, in which 84,753 men aged 35 to 79 years provided information on vasectomy status at recruitment and were followed for prostate cancer and death. Overall, 15% had vasectomy at recruitment.
Overall Risk
During an average follow-up of 15.4 years, 4,377 men were diagnosed with prostate cancer, including 641 (14.6%) with self-reported vasectomy at recruitment. In an analysis stratifying for recruitment center and age at recruitment and adjusting for body mass index, smoking status, marital status, educational attainment, alcohol consumption, physical activity, and protein from dairy sources, vasectomy was not associated with a prostate cancer risk (hazard ratio [HR] = 1.05, 95% confidence interval [CI] = 0.96–1.15). No significant association of vasectomy with death due to prostate cancer was observed (HR = 0.88, 95% CI = 0.68–1.12).
Risk in Subgroups
No evidence for heterogeneity was observed in the association between prostate cancer and vasectomy by stage of disease or years since vasectomy. Significant heterogeneity by tumor grade (P = .02) was observed, with vasectomy being associated with an increased risk of low-intermediate grade (HR = 1.14, 95% CI = 1.01–1.29) but not high-grade prostate cancer (HR = 0.83, 95% CI = 0.64–1.07).
Significant heterogeneity (P = .04) was observed according to median age at vasectomy (38 years), with vasectomy at a younger age (HR = 1.18, 95% CI = 1.03–1.35) but not an older age (HR = 0.99, 95% CI = 0.89–1.09) being associated with an increased risk of prostate cancer. Significant heterogeneity was also observed according to median alcohol consumption (P = .03), with patients below median (HR = 1.16, 95% CI = 1.02–1.31) but not above median consumption (HR = 0.96, 95% CI = 0.84–1.08) having an increased risk.
The investigators concluded: “These findings from a large European prospective study show no elevated risk for overall, high-grade or advanced-stage prostate cancer, or death due to prostate cancer in men who have undergone a vasectomy compared with men who have not.”
The study was supported by Cancer Research UK and the Clarendon Fund, University of Oxford.
Karl Smith Byrne, MPhil, of Nuffield Department of Population Health, University of Oxford, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
