Vasectomy and Risk of Aggressive Prostate Cancer: A 24-year Follow-Up Study

J Clin Oncol. 2014 Sep 20;32(27):3033-8. doi: 10.1200/JCO.2013.54.8446.

Abstract

Purpose: Conflicting reports remain regarding the association between vasectomy, a common form of male contraception in the United States, and prostate cancer risk. We examined prospectively this association with extended follow-up and an emphasis on advanced and lethal disease.

Patients and methods: Among 49,405 U.S. men in the Health Professionals Follow-Up Study, age 40 to 75 years at baseline in 1986, 6,023 patients with prostate cancer were diagnosed during the follow-up to 2010, including 811 lethal cases. In total, 12,321 men (25%) had vasectomies. We used Cox proportional hazards models to estimate the relative risk (RR) and 95% CIs of total, advanced, high-grade, and lethal disease, with adjustment for a variety of possible confounders.

Results: Vasectomy was associated with a small increased risk of prostate cancer overall (RR, 1.10; 95% CI, 1.04 to 1.17). Risk was elevated for high-grade (Gleason score 8 to 10; RR, 1.22; 95% CI, 1.03 to 1.45) and lethal disease (death or distant metastasis; RR, 1.19; 95% CI, 1.00 to 1.43). Among a subcohort of men receiving regular prostate-specific antigen screening, the association with lethal cancer was stronger (RR, 1.56; 95% CI, 1.03 to 2.36). Vasectomy was not associated with the risk of low-grade or localized disease. Additional analyses suggested that the associations were not driven by differences in sex hormone levels, sexually transmitted infections, or cancer treatment.

Conclusion: Our data support the hypothesis that vasectomy is associated with a modest increased incidence of lethal prostate cancer. The results do not appear to be due to detection bias, and confounding by infections or cancer treatment is unlikely.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Prospective Studies
  • Prostatic Neoplasms / epidemiology*
  • Prostatic Neoplasms / mortality
  • Prostatic Neoplasms / pathology*
  • Risk Assessment
  • Risk Factors
  • United States / epidemiology
  • Vasectomy / adverse effects*