A Retrospective Cohort Study of Vasectomy and Prostate Cancer in US Men

Abstract

These results support evidence from other epidemiologic studies that vasectomy increases risk of prostate cancer. A biological mechanism whereby vasectomy influences the rate of prostate cancer may be related to a diminished secretory rate of prostatic fluid following vasectomy, or, alternatively, to the postvasectomy immune response to sperm antigens, which may cross-react with tumor-associated antigens and suppress tumor immunosurveillance mechanisms.

A cross-sectional study of vasectomy, time since vasectomy and prostate cancer

“…The study of Honda et al 16 found the relative risk of prostate cancer was higher among men who had a vasectomy 30 y than among men who had no vasectomy or had a vasectomy less than 30 y. Hayes et al 20 reported a higher risk of prostate cancer for men having had a vasectomy 20 y. Mettlin et al 19 reported an increased risk for men who had a vasectomy 13±18 y prior to a diagnosis of prostate cancer but not among men who had a vasectomy 19±44 y prior. The most recent reports by Giovannucci et al 12,13 similarly note this association. Their retrospective cohort study 13 found a signi®cantly increased relative risk of prostate cancer among men having a vasectomy 20 y prior to a diagnosis of prostate cancer.…”

“…The most recent reports by Giovannucci et al 12,13 similarly note this association. Their retrospective cohort study 13 found a signi®cantly increased relative risk of prostate cancer among men having a vasectomy 20 y prior to a diagnosis of prostate cancer. Their prospective cohort study 12 also reported that the strong association between vasectomy and an elevated risk of prostate cancer was even more pronounced among men who had their vasectomy 22 y in the past.…”

“…A cross-sectional design maximizes the value of a large (b 95 000) population that was accrued to participate in the same study. The time period (1993±1995) was one characterized by considerable public awareness of both prostate cancer and the possible association of vasectomy and prostate cancer because of the publication of the two Giovannucci et al 12,13 reports of a positive association during the peak of PSA testing in the US. Certainly, the percentage of vasectomized men in this study is representative of recently estimated rates in the US 14 and considerably higher in each 10 y age group than prevalence rates established in 1990.…”

“…The production of antisperm antibodies in about half of vasectomized men led to speculation that a compromised immune system may be responsible for increased prostate cancer risk. 11 Giovannucci et al 12,13 suggest a possible increased carcinogenic exposure as a result of the prostate's reduced secretory capacity after vasectomy. However, men regardless of vasectomy status experience less ejaculate as the prostate diminishes with age.…”

“…Numerous reviews (listed in Reference 24), commentaries and methodological critiques 25±27 have appeared. Some studies have showed an association between having had a vasectomy and a diagnosis of prostate cancer, 12,13,16,19,20 but others have not.…”