A phase II study of high-dose estrogens (diethylstilbestrol diphosphate) in prostate cancer.

Twenty-five patients with metastatic prostate cancer resistant to primary hormone therapy, received high-dose intravenous diethylstilbestrol diphosphate (Stilphostrol [Miles Pharm], DES-P) in a Phase II study using established response criteria. Objective response rate was 17%, while 22% of the patients were subjectively improved. Moderate gastrointestinal toxicity was reported in 10 patients (40%). Thromboembolic complications were seen in 2 (8%). The role of high-dose Stilphostrol in the treatment of hormone-resistant prostate cancer is limited.