Bimal Bhindi, MDCM, MSc
R. Jeffrey Karnes, MD
A systematic review and meta-analysis has found no association between vasectomy and high-grade, advanced, or fatal prostate cancer but a weak association with any prostate cancer. These findings were reported in JAMA Oncology by Bimal Bhindi et al. R. Jeffrey Karnes, MD, of the Mayo Clinic, Rochester, is the corresponding author of the JAMA Internal Medicine article.
The analysis involved 53 studies, including 16 cohort studies (2,563,519 participants), 33 case-control studies (44,536 participants), and 4 cross-sectional studies (12,098,221 participants). The primary outcome was any diagnosis of prostate cancer.
Of the included studies, 7 cohort studies (44%), 26 case-control studies (79%), and all 4 cross-sectional studies were considered to have a moderate to high risk of bias. Among the studies with a low risk of bias, an association between vasectomy and an increased risk of prostate cancer was identified among the 7 cohort studies (adjusted rate ratio = 1.05, P < .001), with a nonsignificantly increased risk observed among case-control studies (6 studies; adjusted odds ratio = 1.06, P = .54). Effect estimates were further from the null when studies with a moderate to high risk of bias were included.
No significant associations were observed between vasectomy and high-grade prostate cancer (6 cohort studies; adjusted rate ratio = 1.03, P = .67), advanced prostate cancer (6 cohort studies; adjusted rate ratio = 1.08, P = .11), or fatal prostate cancer (5 cohort studies; adjusted rate ratio = 1.02, P = .68).
It was estimated that vasectomy was associated with a 0.6% absolute increase in lifetime risk of prostate cancer, with a population-attributable fraction of 0.5%.
The investigators concluded: “This review found no association between vasectomy and high-grade, advanced-stage, or fatal prostate cancer. There was a weak association between vasectomy and any prostate cancer that was closer to the null with increasingly robust study design. This association is unlikely to be causal and should not preclude the use of vasectomy as a long-term contraceptive option.” ■