A prospective, randomised study to compare goserelin acetate (Zoladex) versus cyproterone acetate (Cyprostat) versus a combination of the two in the treatment of metastatic prostatic carcinoma.

A prospective randomised study was performed to test the hypothesis that total androgen ablation, achieved by combining an LHRH analogue, goserelin acetate (Zoladex), with an antiandrogen, cyproterone acetate (Cyprostat), is more effective than conventional monotherapy in delaying the time to progression of metastatic prostatic cancer. 525 patients were recruited at 18 UK centres between May 1986 and January 1989, 175 patients being allocated to each arm. Patients were clinically and biochemically assessed at 1, 2, 3, 6, 9 and 12 months after initiation of therapy and then every 6 months until a maximum duration of 48 months. There was no statistically significant difference in terms of median time to progression between the combination treatment arm and either monotherapy arm, although there was a statistically significant difference between goserelin acetate alone and cyproterone acetate alone, in favour of goserelin acetate (p = 0.016). All treatment regimens were well tolerated and cyproterone acetate reduced both tumour flare reactions and hot flushes in patients receiving goserelin acetate. It is concluded that total androgen ablation using cyproterone acetate (300 mg/day) and goserelin acetate (3.6 mg every 28 days) confers no advantage in terms of time to progression, to conventional monotherapy, but can reduce certain side effects caused by LHRH analogue treatment alone.

The release of pituitary gonadotrophins by luteinizing hormone releasing hormone in the intact, castrated and aspermatogenic rat.

The change in serum gonadotrophin concentration in response to synthetic Luteinizing Hormone Releasing Hormone (LHRH - 400 ng i.v.) was investigated under barbiturate anaesthesia in adult male rats either chronically castrated, rendered aspermatogenic by the administration of alpha-chlorohydrin 12-16 weeks previously (to remove inhibin), or treated with vehicle. A single injection of LHRH increased serum LH and FSH concentrations similarly in both intact and aspermatogenic rats. In castrated rats the amount of LH released was much greater and the FSH secretion sustained. A second injection produced a similar increase although a second peak of FSH could not be detected in castrated rats as the FSH level was still elevated. The increase in LH levels was two to three times larger in response to the second injection of LHRH than to the first in all groups. The results do not support the hypothesis that the enhanced gonadotropin response to castration in the aspermatogenic rat is due to increased pituitary sensitivity to LHRH.