Incidence and severity of prostate cancer in 360 hypogonadal men treated with testosterone undecanoate injections (TU) for up to 8 years and 296 untreated hypogonadal controls.
50 Background: Testosterone therapy (TTh) in middle-aged and elderly men is still associated with concerns regarding prostate cancer (PCa). In this registry study, we investigated the incidence of PCa in hypogonadal patients on long-term treatment with TU in comparison to an untreated hypogonadal control group (CTRL). Methods: In a cumulative registry study, 360 men (mean age: 57.37±7.29 years, range: 33-70) with testosterone (T) ≤12.1 nmol/L received TU 1000 mg every 12 weeks following an initial interval of 6 weeks for up to 8 years. 296 hypogonadal men (mean age: 64.79±4.28 years, range: 57-74) decided against TTh, mainly due to financial reasons. Prostate volume (PV) and PSA were measured and digital rectal examination (DRE)/ transrectal ultrasound (TRUS) performed before treatment initiation and then regularly every 3-6 months. Biopsies were performed when indicated according to EAU guidelines. Results: From baseline to 8 years, PV increased from 29.24±10.38 to 31.13±11.45 ml in the T group and remained stable from 34.45±5.89 to 33.51±12 in CTRL. PSA increased slightly from 1.74 ± 0.93 to 1.83±0.93 ng/ml in the T group and remained stable from 2.25±1.34 to 2.19±1.17 in CTRL. In T-treated patients, 7 men (1.9%) were diagnosed with PCa. In the control group, 12 (4.1%) were diagnosed with PCa. The incidence per 10,000 years was 30.05 in the T group and 63.54 in CTRL. The mean age of PCa patients was 64 years in the T group and 65 years in CTRL. All patients underwent radical prostatectomy. The predominant Gleason score was 3 in all patients in the T group, lymph nodes and surgical margins were negative. In CTRL, three men had a predominant Gleason score of 3, 8 had 4, and 1 had 5. 7 patients had positive lymph nodes and no patient had a positive surgical margin. Conclusions: Long-term treatment with TU in hypogonadal men undergoing regular monitoring according to EAU guidelines does not increase the incidence of PCa in comparison to an untreated hypogonadal CTRL group. PCa was more severe in the CTRL group.