Radical prostatectomy: influence on serum and urinary androgen levels.

BACKGROUND: The role of the prostate as an active endocrine organ and the hormonal changes after radical prostatectomy (RP) has not been well studied. The objective of this study was to investigate the serum and urine hormonal changes after RP.
METHODS: Fifty-five healthy men with localized prostate cancer were enrolled in this cross-sectional study at a single academic center. We measured serum levels of testosterone, dihydrotestosterone (DHT), sex hormone binding globulin (SHBG), luteinizing hormone (LH), and follicle stimulating hormone (FSH) in all 55 patients preoperatively and in 53 patients 90 days postoperatively. Free testosterone was calculated in all patients. Inhibin B levels was analyzed in 44 patients pre- and postoperatively. Steroid urine profile including testosterone, DHT, 5alpha-androstane-3alpha,17beta-diol (3alphaAdiol), and androsterone (ADT) was also determined preoperatively and 90 days postoperatively in 18 patients.
RESULTS: There were 53% increase in serum LH (P < 0.0001), 21% increase in serum FSH (P < 0.0001), and 13% decrease in DHT levels (P < 0.03). There were no significant changes in any other serum hormone investigated. Urinary levels of DHT glucuronides (DHT-G) decreased by 67% (P < 0.0003) while Androsterone-G and 3alphaAdiol-G increased by 37% (P = 0.019) and 44% (P = 0.023), respectively. There were no alterations in the urinary levels of the other steroids investigated. Inhibin B levels correlated inversely with both FSH (r = -0.67, P < 0.0001) and LH (r = -0.51, P = 0.0004).
CONCLUSION: RP leads to significant increases in serum gonadotropins and significant DHT decrease in both serum and urine. These hormonal changes are independent of inhibin B.