Men who undergo a vasectomy do not have an increased risk for developing prostate cancer, according to a study in BMJ.

Madhur Nayan, PhD, from the Princess Margaret Cancer Centre at the University of Toronto, and colleagues identified 326,607 men aged 20 to 65 who had undergone vasectomy between April 1, 1994, and December 31, 2012. Excluded from the study were men already diagnosed with prostate cancer and those who underwent a vasovasostomy.

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The primary outcome of the men tested was incident prostate cancer, defined as the first recorded date of prostate cancer diagnosis in the Ontario Cancer Registry. Secondary outcomes included prostate cancer related grade (low, intermediate, or high), stage (localized or advanced), and mortality.

During the 18-year study period, 3,462 incident cases of prostate cancer were identified: 53.2% in the vasectomy group and 46.8% in the non-vasectomy group. In the unadjusted analyses, vasectomy was associated with a modest but statistically significant increase in risk of prostate cancer (CI 1.05 to 1.20). Variables found to be different between the groups were patient visits to specialists, urologists, and emergency departments in the year before April 1, 1994, and visits to general practitioners between the index date and December 31, 2012. After adjusting for these variables, the researchers found that the association between vasectomy and incident prostate cancer was no longer discernible.

No association was found between vasectomy and prostate cancer after restricting analyses to men with follow-up at least to age 50 or 60. Vasectomy was not associated with an increased risk of intermediate or high grade cancer in any analyses, or any advantage stage at diagnosis in any analyses. Mortality from prostate cancer was not related to vasectomy.

According to the researchers, “We observed no statistically significant association between vasectomy and prostate cancer related risk, grade, stage or mortality. Our findings have important implications for patients, clinicians, guidelines, policy makers, and family planning support groups.”


  1. Nayan M, Hamilton RJ, Macdonald EM, et al. Vasectomy and risk of prostate cancer: population based matched cohort study. BMJ. 3 November 2016. doi: