[Effect of estramustine phosphate on hormone refractory prostate cancer]

Clinical effects of estramustine phosphate (EMT) on hormone refractory prostate cancer were studied. Prostate cancer relapsed in 70 of the 259 patients with stage C and D diseases who had initially responded to endocrine therapy. After cancer relapse, endocrine therapy was changed to oral administration of EMT in 21 patients, while initial endocrine therapy was continued in 14 and additional radiation therapy was given in 35. A partial response or no change was observed in 11 of the 21 patients (52%) given EMT therapy, the mean duration of the response being 14.2 months. The 21 patients given EMT therapy survived significantly longer than the 14 patients with continued on endocrine therapy, and those responding to EMT therapy tended to have a better survival than those unresponsive. Side effects of EMT included loss of appetite in 2 patients and edema of the lower limb in 1, but they were not severe enough to require discontinuation of the drug. EMT may be a useful drug for patients with advanced prostate cancer with relapse after endocrine therapy.