Phase II trial of tamoxifen in metastatic carcinoma of the prostate

Abstract

Fifty-one patients with advanced metastatic carcinoma of the prostate were treated with the antiestrogen tamoxifen. Thirty-eight of these patients were refractory to prior hormonal manipulation with estrogens and/or orchiectomy, and five (13%) achieved an objective response (partial regression or stable disease using the National Prostate Cancer Project criteria). Median survival of the responders was significantly longer than that of the nonresponders (P less than 0.05). An additional 13 patients who had not previously received hormonal manipulation were treated with tamoxifen; one partial response and three disease stabilizations were noted. Response was separately evaluated for 15 patients with objectively measurable lesions using standard Phase II response criteria. Only 1/15 (7%) partial response and 3/15 (20%) disease stabilizations were documented. Subjective benefit in terms of significant pain relief was noted in 17/50 (34%) of patients. Toxicity was mild, but two possible "tumor flares" were noted. These results do not support the continued investigation of tamoxifen in advanced carcinoma of the prostate.