High-dose diethylstilbestrol diphosphate therapy of prostatic cancer after failure of standard doses of estrogens.

Ten patients with metastatic prostatic cancer no longer responsive to conventional doses of estrogens (stilbestrol 15 mg. daily or equivalent) were treated with high doses of diethylstilbestrol diphosphate. Objective responses lasting from three to fifteen months were obtained in four patients; three of the patients had previously shown progressive disease following orchidectomy.Toxic manifestations consisted mainly of increased gynecomastia and water retention. No serious cardiovascular complications were encountered. This dose-response effect of estrogens indicates the persistence of hormone-dependent tumours in some patients with recurrent disease despite conventional estrogen therapy.