Prostatic cancer and SCH-13521: II. Histological alterations and the pituitary gonadal axis.

We herein report on the results of treatment of 13 men with stage D prostatic carcinoma with a non-steroidal compound, SCH-13521 (flutamide). The dosage of the drug was 750 mg. in 3 divided doses daily and treatment extended for 2 to 20 months. Two patients failed to respond in any fashion, 7 had objective evidence of response and the others had varying degrees of subjective response. Plasma testosterone was never suppressed and sexual potency was not altered by the drug. Gynecomastia occurred in several patients, 1 patient had intractable vomiting and 2 had thromboembolic disease. In tissue biopsies after therapy, cytotoxic changes in some acinar cells were noted but healthy-appearing neoplastic cells were always abundant. These observations suggest the pre-treatment existence of autonomous cells that no conventional hormonal manipulation will succeed in destorying. However, the palliation that flutamide seems to afford makes it important to conduct an appropriately designed study that will compare it in a suitable fashion to the effectiveness of diethylstilbestrol.