Tamoxifen in advanced prostatic carcinoma. A dose escalation study

Patients with advanced prostatic carcinoma who had received minimal or no prior therapy were treated with tamoxifen citrate in escalating doses from 10 to 50 mg orally twice a day. Twenty-nine courses were evaluated in 17 patients. Entry was limited to patients with measurable sites of disease. There were no objective responses at any dose level in these measurable sites. Acid and alkaline phosphatase were reduced in 0% and 18% of courses, respectively. Serum testosterone increased by an average of 119 ng/ml. Most increases were transient; no tumor flares were observed. Transperineal prostate biopsies in selected patients after completion of treatment showed no evidence of tumor necrosis or alteration in histologic grade of the tumors. Tamoxifen citrate, over the range of doses evaluated, has no activity in metastatic prostatic carcinoma.