Phase III study of combined chemohormonal therapy in metastatic prostate cancer (ECOG 3882): an Eastern Cooperative Oncology Group study

Abstract

This study, a phase III multicenter randomized trial opened by ECOG in April 1983 and closed in June 1986 was designed to evaluate whether a combination of doxorubicin and an intravenous formulation of diethylstilbestrol diphosphate (DES) was superior to doxorubicin alone in men with hormone refractory prostate cancer. All patients received doxorubicin at a dose of 50 mg/m2 iv every 3 wk either alone or with 1 g DES iv daily for 5 d followed by 1 g iv twice weekly for four cycles (12 wk). The 51 evaluable patients with visceral metastases displayed a significantly increased response rate (27% vs 63%) on the combined therapy arm (p = 0.04). However, the 111 evaluable patients with osseous disease exhibited no difference in response rate between either arm with a p-value of >0.99. Similarly, clinical response rates revealed no difference between the two arms. Cases of cardiac toxicity graded as severe, life threatening, or lethal in the combined therapy arm were 10 times more frequent in the combined-therapy arm than in the doxorubicin-alone group (6.75% compared to 0.7%). This difference was statistically significant (p = 0.0041). All of the cases of superficial and deep venous thrombosis occurred on the combined-therapy arm. There were no other significant differences in the numbers of grade 3 or 4 toxic events. The most common toxicity was hematologic. Failure-free survival duration did reach statistical significance in the combined-therapy group (p = 0.012), although the actual durations were short (2.6-3.2 mo). There was no difference in overall survival between the two groups.