Effects of hCG stimulation after withdrawal of long-term oestrogen treatment in patients with prostate carcinoma

Testosterone depletion is the keystone for therapy of patients metastic prostatic carcinoma. Our objective was to investigate Leydig cell function and testosterone levels after withdrawal of long-term endocrine treatment in patients with prostatic carcinoma. Thirteen patients with prostatic carcinoma, previously treated with oestrogens for at least 4 y, were stimulated with 5000 IU human chorionic gonadotrophin (hCG). The stimulation was performed 3-6 y after cessation of the oestrogen therapy. Serum concentrations of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured before and 24 and 48 h after hCG stimulation. Before hCG stimulation all patients had low serum testosterone concentrations (mean 2.0 +/- 0.2 nmol/l) and 24 and 48 h after hCG stimulation the values had not significantly increased (mean 2.4 +/- 0.2 and 2.5 +/- 1.1 nmol/l, respectively). LH and FSH were within or above the normal range before but after hCG stimulation the values significantly increased. In conclusion, the study shows that the Leydig cells were unable to respond to hCG stimulation more than 3 y after cessation of oestrogen therapy. The Leydig cell function seems to be irreversibly impaired by long-term oestrogen treatment.