Testicular endocrine function after withdrawal of oestrogen treatment in patients with carcinoma of the prostate.

The serum concentration of testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH) and prolactin were determined at different intervals after withdrawal of oestrogen treatment in patients with prostatic carcinoma. Oestrogen therapy had been stopped in all patients because of the side effects of oestrogens. There was a negative correlation (r = -0.64) between serum testosterone concentrations and the duration of oestrogen treatment in patients investigated for more than 6 months after withdrawal of hormones. However, the decrease in testosterone concentration seems to be time-dependent. Thus patients who were treated for less than 3 years had normal testosterone concentrations approximately 6 months after withdrawal of the oestrogen therapy. This group of patients had a positive correlation (r = 0.49) between serum testosterone concentration and time elapsed after cessation of therapy. In contrast, patients treated for more than 3 years retained low testosterone concentrations even after 6 months. The other hormones did not vary between the groups. It is concluded that patients with carcinoma of the prostate treated with oestrogens for more than 3 years have an impaired Leydig cell function which might be irreversible.