Testosterone Replacement Therapy and the Risk of Prostate Cancer in Men With Late-Onset Hypogonadism

The association between the use of testosterone replacement therapy (TRT) and prostate cancer remains uncertain. Thus, we investigated whether TRT is associated with an increased risk of prostate cancer in men with late-onset hypogonadism. We used the UK Clinical Practice Research Datalink to assemble a cohort of 12,779 men who were newly diagnosed with hypogonadism between January 1, 1995, and August 31, 2016, with follow-up until August 31, 2017. Exposure to TRT was treated as a time-varying variable and lagged by 1 year to account for cancer latency, with nonuse as the reference category. During 58,224 person-years of follow-up, a total of 215 patients were newly diagnosed with prostate cancer, generating an incidence rate of 3.7 per 1,000 person-years. In time-dependent Cox proportional hazards models, use of TRT was not associated with an overall increased risk of prostate cancer (hazard ratio = 0.97; 95% confidence interval: 0.71, 1.32) compared with nonuse. Results remained consistent in secondary and sensitivity analyses, as well as in a propensity score-matched cohort analysis that further assessed the impact of residual confounding. Overall, the use of TRT was not associatedwith an increased risk of prostate cancer inmen with late-onset hypogonadism.