Abstract
Peripheral serum concentrations of FSH, LH, prolactin and ACTH were measured in 22 patients with advanced prostatic carcinoma treated by castration, polyestradiol phosphate (Estradurin®) administration and a combination of castration and Estradurin® administration during the first 12 months of treatment. Estradurin® treatment alone (80 mg i.m. once a month) did not result in any significant changes in the circulating concentrations of FSH, LH and prolactin. Therefore, the clear-cut inhibition of testicular steroidogenesis observed under this kind of treatment does not appear to be due to an inhibition of pituitary gonadotropin secretion, and is most likely due to a direct estrogen effect on Leydig cells. Castration led to grossly elevated serum FSH and LH levels. In this group, serum FSH remained at a high level, whereas LH was close to pretreatment levels 9 months after castration, suggesting differences in pituitary capacity to secrete FSH and LH under these conditions. Concentrations of circulating FSH, and to a lesser extent LH, in the combination treatment group were between those found in the castration and estrogen-only treatment groups, suggesting that the secretion of both gonadotropins can be suppressed by estrogen. No changes in serum prolactin and ACTH concentrations were seen in the three treatment groups.