Association between prostate cancer and serum testosterone levels

BACKGROUND. The purpose of the current study was to determine whether the presence of prostate cancer altered serum testosterone levels. METHODS. Initially, we evaluated both serum total and free testosterone levels in patients with either high-grade (n = 18) or moderate-grade (n = 146) prostate cancer, detected by prostate needle biopsies. Then both serum total and free testosterone levels, before and after prostatectomy, were compared in 79 of the 164 men with prostate cancer. RESULTS. In the first setting, serum total and free testosterone levels (307 +/- 24 ng/dl and 1.14 +/- 0.09 ng/dl) in patients with high-grade prostate cancer were significantly lower than those in patients with moderate-grade prostate cancer (452 +/- 12 ng/dl and 1.51 +/- 0.04 ng/dl) and those without prostate cancer (451 +/- 17 ng/dl and 1.55 +/- 0.06 ng/dl). After prostatectomy in 79 patients with prostate cancer, serum levels of both total and free testosterone (511 +/- 15 ng/dl and 1.78 +/- 0.05 ng/dl) were found significantly elevated when compared with their respective presurgical total and free testosterone levels (450 +/- 17 ng/dl and 1.60 +/- 0.06 ng/dl). CONCLUSION. Our findings show that serum total and free testosterone levels in patients with prostate cancer are altered, supporting the possibility that prostate cancer may inhibit serum testosterone levels.