Pituitary function after orchiectomy in patients with or without earlier estrogen treatment for prostatic carcinoma

Testosterone, FSH, LH and prolactin were measured before, and up to 36 months after orchiectomy in 62 patients with prostatic carcinoma; 36 were treated by primary orchiectomy, 10 by orchiectomy after prior estrogen treatment for less than 3 yr (short-term) and 16 for more than 3 yr (long-term). Before orchiectomy serum levels of testosterone, FSH and LH were significantly lower in estrogen-treated than in untreated patients. Following orchiectomy serum FSH and LH increased in all patients studied. However, long-term estrogen-treated patients had significantly lower FSH and LH both before orchiectomy and during the follow-up period than those treated by primary orchiectomy or orchiectomized after short-term estrogen treatment. In addition, in those long-term estrogen-treated patients, serum testosterone did not significantly decrease after orchiectomy, whereas in patients treated by primary orchiectomy or orchiectomized after short-term estrogen treatment serum testosterone fell significantly. At follow-up comparable levels of testosterone were found in the three patient groups studied. Prolactin levels did not differ significantly between the patient groups and were not elevated either before or after orchiectomy. It is suggested that patients with carcinoma of the prostate treated with estrogen for more than 3 yr have impaired, but slowly increasing, pituitary gland function, possibly caused by long-term effect of estrogen on the pituitary gland.