A Comparison of Estramustine Phosphate and Streptozotocin in Patients with Advanced Prostatic Carcinoma Who Have Had Extensive Irradiation

Abstract
In this 2nd nationally randomized cooperative chemotherapy trial of the National Prostatic Cancer Project 125 patients with histologically confirmed progressing advanced carcinoma of the prostate (clinical stage D) who had prior pelvic irradiation of at least 2000R received as initial therapy 1 of 2 nonmyelosuppressive agents, estramustine phosphate or streptozotocin, for comparison with patients randomized to receive standard treatment. Patients whose disease was progressive after 12 wk on chemotherapy were crossed over to receive the alternate therapeutic agent. Response to treatment was evaluated in 105 patients on the basis of previously established and defined criteria. All known prognostic factors were comparable among the 3 treatment arms. The objective response rates to therapy were 19% in the standard arm (stable only), 30% in the estramustine phosphate arm (stable and partial regression) and 32% in the streptozotocin arm (stable arm). Thus far, 4 patients crossed to estramustine phosphate and 2 patients crossed to streptozotocin responded to therapy. In a number of response parameters estramustine phosphate had an advantage over the other 2 treatment arms. Nausea and vomiting were the predominant toxicities patients in all treament arms. Average survival time is longer for patients receiving the chemotherapies. Estramustine phosphate seems to be the superior drug and both chemotherapies are superior to standard treatment. A significant number of patients are still being treated actively and followed, and their responses will affect the final conclusions only more favorably.