Cyproterone acetate lead-in prevents initial rise of serum testosterone induced by luteinizing hormone-releasing hormone analogs in the treatment of metastatic carcinoma of the prostate.

Luteinizing hormone-releasing hormone (LH-RH) analogs are an effective treatment of metastatic carcinoma of the prostate. However, they induce an initial rise in serum testosterone responsible for 10-30% of diseases flares. The efficacy of the antiandrogen cyproterone acetate (CPA) was tested in 15 patients with metastatic carcinoma of the prostate. 10 patients were given 100 mg CPA t.i.d. from day 1 to 14 in association with the LH-RH analog Buserelin, 500 micrograms t.i.d., from day 7 to 14.5 patients were given CPA and Buserelin at the same doses from day 1 to 7. Serum testosterone determinations were obtained on days 1-7, 8, 11 and 14, at 08.00 h, and on days 8, 11, 1 h after each analog injection in group 1, and on days 1, 4 and 7 at 08.00 h and 1 h after each analog injection in group 2. All the patients were then treated by orchidectomy. Pretreatment with CPA blunted the initial rise of testosterone which never rose above pretreatment levels. Simultaneous treatment had no demonstrable effects on the rise of serum testosterone. It is concluded that pretreatment with CPA allows a safer use of LH-RH analogs in the treatment of metastatic carcinoma of the prostate.