Prostate Cancer Diagnosis Rates among Insured Men with and without HIV in South Africa: A Cohort Study.

Background: Several studies have found lower prostate cancer diagnosis rates among men with human immunodeficiency virus (HIV; MWH) than men without HIV but reasons for this finding remain unclear.

Methods: We used claims data from a South African private medical insurance scheme (July 2017- July 2020) to assess prostate cancer diagnosis rates among men aged ≥ 18 years with and without HIV. Using flexible parametric survival models, we estimated hazard ratios (HR) for the association between HIV and incident prostate cancer diagnoses. We accounted for potential confounding by age, population group, and sexually transmitted infections (confounder-adjusted model) and additionally for potential mediation by prostatitis diagnoses, prostate-specific antigen testing, and prostate biopsies (fully adjusted model).

Results: We included 288,194 men, of whom 20,074 (7%) were living with HIV. Prostate cancer was diagnosed in 1,614 men without HIV (median age at diagnosis: 67 years) and in 82 MWH (median age at diagnosis: 60 years). In the unadjusted analysis, prostate cancer diagnosis rates were 35% lower among MWH than men without HIV [HR, 0.65; 95% confidence interval (CI), 0.52-0.82]. However, this association was no longer evident in the confounder-adjusted model (HR, 1.03; 95% CI, 0.82-1.30) or in the fully adjusted model (HR, 1.14; 95% CI, 0.91-1.44).

Conclusions: When accounting for potential confounders and mediators, our analysis found no evidence of lower prostate cancer diagnosis rates among MWH than men without HIV in South Africa.

Impact: Our results do not support the hypothesis that HIV decreases the risk of prostate cancer.