Prospective Evidence on Vasectomy and Prostate Cancer Risk: A Systematic Review and Meta-Analysis with ROBINS‑E Bias Assessment — The Association Specialists
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Prospective Evidence on Vasectomy and Prostate Cancer Risk: A Systematic Review and Meta-Analysis with ROBINS‑E Bias Assessment (23894)

Rani RRC Chand 1 2 , Chifeng CT Tan 2 , Pavla PV Vaneckova 2 , Suzanne SH Hughes 2 , Chelsea CCH Harrison 2 , Karen KC Chiam 2 , Jennifer JS Stone 3 , Manish MP Patel 4 5 , David DPS Smith 2 , Michael MD David 2 6 , Visalini VN-S Nair-Shalliker 2
  1. Sydney School of Public Health, The University of Sydney, Sydney, NSW, Australia
  2. The Daffodil Centre, The University of Sydney, Cancer Council , Sydney, NSW, Australia
  3. JBI, School of Public Health, Adelaide University, Adelaide, South Australia, Australia
  4. Sydney Medical School, University of Sydney , Sydney, NSW, Australia
  5. Department of Urology, Westmead Hospital, Sydney, NSW, Australia
  6. School of Medicine & Dentistry, Griffith University, Gold Coast, Queensland, Australia

Background

Vasectomy is associated with advanced prostate cancer, although evidence is inconsistent due to limited transparency in bias assessments. This review evaluated the association between vasectomy and prostate cancer risk using prospective studies and assessed risk of bias using the Risk Of Bias In Non-randomized Studies (ROBINS-E) tool, which is specifically designed for non-randomised exposure studies.

Methods

A systematic search of Medline, Embase, Web of Science, Scopus, and Cochrane identified prospective studies published from January 1993 to April 2025. Eligible studies compared vasectomised with non‑vasectomised men and reported effect estimates (hazards ratios) with 95% confidence intervals. The primary outcome was prostate cancer diagnosis, classified by TNM stage (localised advanced) and Gleason score (low, low-to-intermediate, intermediate, high risk) with prostate cancer–specific mortality as the secondary outcome. Risk of bias was assessed using the ROBINS‑E tool across seven domains.

Results

Of 3,268 records identified, 15 prospective cohort studies were included after screening. The ROBINS‑E assessment identified 12 studies with low to moderate risk of bias: localised risk (6), advanced risk (7), low‑risk (4), low-to-intermediate‑risk (2), and intermediate-risk (4), high-risk (7), and prostate cancer–specific mortality (6). Using a random-effects model, vasectomy was associated with a small but statistically significant increased risk of overall prostate cancer (HR 1.06; 95% CI 1.03–1.08), localised (HR 1.06; 95% CI 1.02–1.09), low-risk (HR 1.08; 95% CI 1.00–1.16), and intermediate-risk (HR 1.10; 95% CI 1.03–1.19). No significant association was observed for advanced (HR 1.09; 95% CI 0.98–1.20) or high-risk (HR 1.03; 95% CI 0.94–1.13). Vasectomy was associated with reduced prostate cancer–specific mortality (HR 0.87; 95% CI 0.78–0.98).

Conclusion

Vasectomy was associated with modest increases in lower‑risk prostate cancer but not aggressive disease, and with reduced prostate cancer mortality. Further research in diverse populations is needed to clarify these patterns.