Moderate dose diethylstilbestrol diphosphate therapy in hormone refractoryprostate cancer

Objective: To examine the efficacy and toxicity of a moderate dose (250 mg/ day) of diethylstilbestrol diphosphate DES-DP) intravenously administered t o patients with hormone refractory prostate cancer (HRPC) as well as the in fluence of this agent on the endocrine system. Patients and methods: Sixteen patients with HRPC were treated with a daily intravenous injection of 250 mg of DES-DP for 28 days. Eastern Cooperation Oncology Group (ECOG) performance status and pain score were used for subje ctive evaluation and PSA was used for objective evaluation. Testosterone, f ree testosterone, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) were used for hormonal parameters. Results: Fourteen patients were eligible. The mean patient age was 75.2 yea rs. With respect to the ECOG pain score, 5 patients scored 1 or higher, in 4 patients, the pain completely disappeared, and in 1 patient, the pain sco re improved from 4 to 1. The PSA level decreased significantly from 528 +/- 556 ng/ml (mean +/- SD) to 154 +/- 197 ng/ml. The DHEA level was not chang ed during DES-DP administration. The DHEA-S level decreased significantly f rom 882 +/- 430 ng/ml to 480 +/- 236 ng/ml. Testosterone and free testoster one were in the castration level before and during the treatment. Toxicity was minimal. None of the patients developed cardiovascular disorder. Conclusion: A moderate dose (250 mg/day) of DES-DP decreased PSA levels and relieved pain without causing serious toxicity in patients with HRPC. It i s suggested that the mechanism of the DES-DP effect on the decrease in PSA and pain relief involves a decrease in DHEA-S.