Testosterone treatment is not associated with increased risk of prostate cancer or worsening of lower urinary tract symptoms: prostate health outcomes in the Registry of Hypogonadism in Men

Objectives: To evaluate the effects of testosterone-replacement therapy (TRT) on prostate health indicators in hypogonadal men, including rates of prostate cancer diagnoses, changes in prostate-specific antigen (PSA) levels and lower urinary tract symptoms (LUTS) over time. Patients and Methods: The Registry of Hypogonadism in Men (RHYME) is a multi-national patient registry of treated and untreated, newly-diagnosed hypogonadal men (n = 999). Follow-up assessments were performed at 3–6, 12, 24, and 36 months. Baseline and follow-up data collection included medical history, physical examination, blood sampling, and patient questionnaires. Prostate biopsies underwent blinded independent adjudication for the presence and severity of prostate cancer; PSA and testosterone levels were measured via local and central laboratory assays; and LUTS severity was assessed via the International Prostate Symptom Score (IPSS). Incidence rates per 100 000 person-years were calculated. Longitudinal mixed models were used to assess effects of testosterone on PSA levels and IPSS. Results: Of the 999 men with clinically diagnosed hypogonadism (HG), 750 (75%) initiated TRT, contributing 23 900 person-months of exposure. The mean testosterone levels increased from 8.3 to 15.4 nmol/L in treated men, compared to only a slight increase from 9.4 to 11.3 nmol/L in untreated men. In all, 55 biopsies were performed for suspected prostate cancer, and 12 non-cancer related biopsies were performed for other reasons. Overall, the proportion of positive biopsies was nearly identical in men on TRT (37.5%) compared to those not on TRT (37.0%) over the course of the study. There were no differences in PSA levels, total IPSS, or the IPSS obstructive sub-scale score by TRT status. Lower IPSS irritative sub-scale scores were reported in treated compared to untreated men. Conclusions: Results support prostate safety of TRT in newly diagnosed men with HG.