Vasectomy and the risk of prostate cancer in a prospective US Cohort: Data from the NIH‐AARP Diet and Health Study

Abstract

Background: Several studies have linked vasectomy with the risk of prostate cancer; however, this association has been attributed to selection bias. Since vasectomy is a common and effective form of contraception, these implications are significant. Therefore, we sought to test this association in a large observational cohort. Objective: To evaluate the potential association between prior vasectomy and the risk of developing prostate cancer. Materials and Methods: We evaluated the relationship between vasectomy and prostate cancer in the NIH-AARP Diet and Health Study. Of the 111,914 men, prostate cancer was identified in 13,885 men and vasectomies were performed in 48,657. We used multivariate analysis to examine the relationship between prostate cancer and vasectomy. We also performed propensity score-adjusted and propensity score-matched analysis. Results: Men utilizing vasectomy were more likely to be ever married, fathers, educated, white, and screened for prostate cancer. During 4,251,863 person-years of follow-up, there was a small association between vasectomy and incident prostate cancer with a hazard ratio of 1.05 (95% CI, 1.01-1.11). However, no significant association was found when looking separately at prostate cancer by grade or stage. Conclusions were similar when using propensity adjustment and matching. Importantly, a significant interaction between vasectomy and PSA screening was identified. Discussion: Estimates of the association between vasectomy and prostate cancer are sensitive to analytic method underscoring the tenuous nature of the connection. Given the differences between men who do and do not utilize vasectomy, selection bias appears likely to explain any identified association between vasectomy and prostate cancer. Conclusions: With over 20 years of follow-up, no convincing relationship between vasectomy and prostate cancer of any grade was identified.

Review of Vasectomy Complications and Safety Concerns

“…Such reports have been discovered in the early 1990s [ 42 ], and data anomalies caused by various risks of bias have not been ruled out [ 42 43 ]. It was mainly focused on high-grade/low-grade cancer and lethality that increased overall risk of prostate cancer which reported by literatures ( Table 2 ) [ 44 45 46 47 ]. It has also been reported that the incidence of prostate cancer after vasectomy exhibits a slight increase, but mortality after vasectomy has been markedly reduced [ 48 ].…”

Vasectomy and Risk of Prostate Cancer: A Systematic Review and Meta-analysis

“…A total of 466 unique records were identified. Of these, 70 full-text articles were assessed for eligibility and 37 met the inclusion criteria for qualitative and quantitative analysis [4] , [6] , [7] , [8] , [9] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] . The reasons for exclusion are summarized in Figure 1 .…”

“…These discrepancies are due to the paucity of documented causal associations, and possible detection biases related to PCa screening and closer follow-up among vasectomy patients, and modest clinical significance with a relative risk very often close to 1. Recently, several large, high-quality reports demonstrated conflicting results [5] , [6] , [7] , [8] , [9] . A recent meta-analysis that included the most recent reports found that vasectomy was associated with localized and advanced PCa [10] .…”

Impact of Vasectomy on the Development and Progression of Prostate Cancer: Preclinical Evidence

“…There are numerous studies assessing the potential health risks associated with vasectomy, including subsequent development of prostate cancer. Indeed, a substantial number of cohort and case-control studies have shown an elevated risk of prostate cancer in men who have undergone vasectomy, with an odds ratio (OR) up to 5.3 in US studies ( Figure S1 ) [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. However, some of these studies have been criticized as suffering from detection bias or surveillance bias.…”