Randomised study of Casodex 50 MG monotherapy vs orchidectomy in the treatment of metastatic prostate cancer. The Scandinavian Casodex Cooperative Group.

The effect of Casodex (ICI 176,334), a new, once-daily, selective antiandrogen, given as 50 mg monotherapy, was compared with orchidectomy in a randomised, multicentre, open study in 376 patients with metastatic prostate cancer. At 3 months, PSA was reduced by 86% in the Casodex group and by 96% in the orchidectomy group. Treatment failed in 51 patients in the orchidectomy group and 66 showed a subjective response. Treatment failed in 86 patients treated with Casodex and 40 patients showed a subjective response. Patients treated with Casodex maintained their sexual interest better than those in the orchidectomy group. Median survival was significantly longer in the orchidectomy group. Casodex was well-tolerated. The most likely reason for the differences between the groups regarding time to treatment failure and survival is that the dose of Casodex was too small. Further studies with higher doses of Casodex are in progress.