Circumcision for HIV prevention in men who have sex with men: an updated meta-analysis

Background While circumcision reduces HIV risk for men who have sex with women, its value for men who have sex with men (MSM) remains unclear. Any protection would be for primarily-insertive MSM (PI-MSM) and could have substantial impact given high incidence. Prior meta-analyses were ambiguous due to inconsistent, highly-confounded data, leaving the total weight of evidence unclear even after a small 2024 trial in PI-MSM showed protection. Setting No geographic or other setting restrictions were used. Methods We performed an updated literature search for data on the association of male circumcision with HIV among MSM. We conducted descriptive analyses and a random-effects meta-analysis to assess the main association among PI-MSM. To isolate the protective effect of circumcision from potential confounding factors, we also performed a confounder-adjusted meta-analysis, comparing the effect of circumcision on HIV status among primarily-insertive MSM versus among other (non-primarily-insertive) MSM in studies with stratified results. Results Forty-nine studies were included in the descriptive analysis, 13 in the unadjusted meta-analysis, and 10 in the confounder-adjusted meta-analysis. In the unadjusted meta-analysis, circumcision was associated with a lower risk for HIV among PI-MSM (odds ratio (OR) = 0.57, 95% CI: 0.33-0.98); publication bias was present. In the confounder-adjusted analysis, the additional effect of circumcision in the PI-MSM group – a ratio of ORs - was 0.53 (95% CI: 0.34– 0.83), indicating a lower bound on the protective effect of circumcision among PI-MSM adjusting for confounding factors. Publication bias was not present. Conclusions Among PI-MSM, circumcision was protective against HIV. Findings support male circumcision as an effective HIV prevention method for PI-MSM, alongside established combination prevention methods including pre-exposure prophylaxis.