Vasectomy–prostate cancer association unlikely
medwireNews: Two independent studies find that undergoing vasectomy does not increase the risk of prostate cancer incidence or mortality.
These findings are contrary to those of a previous analysis of the Health Professionals Follow-Up Study, which showed that vasectomy increased the risk of prostate cancer by approximately 10% and that of high-grade and lethal disease by 20%.
The first of the current studies, which used data from several healthcare databases in Ontario, Canada, included 326,607 men aged 20 to 65 years who had undergone vasectomy and an equal number of men – matched for age, year of cohort entry, comorbidity score, and geographic area – who had not.
During a median follow-up of 10.9 years, 3462 cases of prostate cancer were identified – 53.2% in the vasectomy group and 46.8% in the non-vasectomy group.
After adjusting for confounding factors, including measures of healthcare seeking behavior such as visits to specialists and urologists, vasectomy was not associated with an elevated risk of prostate cancer (hazard ratio [HR]=1.02).
Furthermore, Madhur Nayan (University Health Network and the University of Toronto, Ontario, Canada) and team did not find a significant association between vasectomy and either high-grade or advanced-stage prostate cancer, or prostate cancer-specific mortality.
They conclude in The BMJ: “These findings have important implications for patients, clinicians, guidelines, policy makers, and family planning support groups, and support the use of vasectomy as a safe method of contraception in men.”
The second study, published in the Journal of Clinical Oncology, used data from the Cancer Prevention Study (CPS)-II and the CPS-II Nutrition cohorts.
Among 363,726 male participants of CPS-II, 42,105 of whom had undergone vasectomy, the procedure was not associated with prostate cancer mortality after adjusting for confounding factors including age, race, body mass index, smoking, education, and prostate-specific antigen testing (HR=1.01).
And neither was vasectomy linked to either overall prostate cancer incidence or high-grade (≥8 Gleason score) prostate cancer incidence among the subset of 66,542 men enrolled in the CPS-II Nutrition cohort, reports the team from the American Cancer Society in Atlanta, Georgia, USA.
Eric Jacobs and co-authors conclude: “Because this study, like all observational studies, has some potential for bias, a small increase in risk cannot be entirely ruled out.
“However, our results provide some reassurance that vasectomy is unlikely to meaningfully increase risk of prostate cancer.”
medwireNews is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016