Anticancer effect of combination therapy of VP16 and fosfesterol in hormone-refractory prostate cancer

Abstract

Objectives: We conducted the present study to evaluate the safety profile and therapeutic value of a combination of etoposide and fosfestrol for treatment of hormone-refractory prostate cancer (HRPC).

Methods: Forty patients with HRPC were included in the study. The median age was 71 years (range, 50-86 years), the Gleason's score ranged from 5 to 10, and the median prostate-specific antigen level was 62.6 ng/mL (range, 4.738-30789 ng/mL). The patients received oral etoposide 25 mg/d and fosfestrol 300 mg/d.

Results: The response rate in terms of measurable disease, serum prostate-specific antigen level, and overall evaluation was 36.8% (CR: 18.4%; PR: 18.4%), 80% (CR: 55%; PR: 25%), and 40% (CR: 20%; PR: 20%) with a median duration of response of 13.6, 13.5, and 13.5 months, respectively. An objective clinical response for overall evaluation was shown by 90% (CR: 20%; PR: 20%; SD: 50%) of the patients, with a median response duration of 15.7 months; 16 patients (40%) are currently alive without recurrence after a median follow-up period of 21.2 months. The overall survival and progression-free survival was 30.5% and 28.8% at 40 months, respectively. No grade III toxicities occurred in any of the patients. Serial measurements in 34 patients using the Functional Assessment of Cancer Therapy-Prostate showed a significant improvement in quality of life as a result of the therapy.

Conclusions: The combination of oral etoposide and fosfestrol is active in patients with HRPC. The regimen is tolerable and has a significant impact on quality of life as measured by the Functional Assessment of Cancer Therapy-Prostate in a limited sample of patients.