Estramustine phosphate--hormone, chemotherapeutic agent, or both?

Estramustine phosphate, a combination steroid and alkylating agent, has been used for treatment of cancer of the prostate since 1969. We treated 32 patients with Stages C and D prostate cancer with this compound. Using the National Prostatic Cancer Project criteria of response, no patient achieved complete or partial objective response. Sixty-two per cent of the patients without prior hormonal manipulation and 12 per cent of those who were progressing following hormonal therapy met the criteria for a stable response. Both Stage C patients, 50 per cent of D1 and 28 per cent of D2 patients achieved disease stabilization for a mean duration of 14.8 months. There was no correlation between tumor grade and response to treatment. Fifty per cent of the patients whose elevated acid phosphatase declined remain stable, whereas 80 per cent in whom the acid phosphatase did not decline have progressed. Estramustine is effective in patients without prior hormonal manipulation. In those refractory to hormones, the prognosis is poor yet data exist to support the superiority of estramustine phosphate over conventional therapy.