For this study, 400 men with testosterone ≤350 ng/dL and symptoms received testosterone undecanoate 1000 mg replacement therapy every 3 months for up to 10 years, while 296 hypogonadal men (age 57-74) opted against replacement therapy and formed the control group. Prostate volume, PSA, weight and C-reactive protein (CRP) were assessed, and digital rectal examination/transrectal ultrasound was performed prior to testosterone therapy initiation and then every 6-12 months. In the testosterone therapy group, 9 men (2.3%) were diagnosed with prostate cancer, compared to the control arm in which 15 (5.1%) men were diagnosed with prostate cancer. The incidence per 10,000 years was 29 in the testosterone group and 102 in in the control group. Interestingly, radical prostatectomy was performed in all men, and in the testosterone group, all men had Gleason score ≤6 disease.
