Oral estramustine plus oral etoposide in the treatment of hormone refractory prostate cancer patients: A phase II study with a 5-year follow-up

Background: Chemotherapy regimens that target microtubular trafficking were repeatedly found to be active in the treatment of hormone refractory prostate cancer patients, but disease responses were reportedly short-lived on average. Materials and methods: From 1994 to 1997, 46 consecutive patients with hormone refractory prostate cancer were enrolled in a multicenter Phase II trial of oral etoposide 100 mg/day and estramustine 560 mg/day for 21 days, followed by a 7-day rest period. Final evaluation of this trial was performed after a follow-up of 5 years. Results: Fifty-four percent of patients attained a PSA response and 46% attained a response on measurable lesions. Median time to progression (TTP) and overall survival were 7.4 and 18.4 months, respectively. Fourteen patients (30.4%) had a TTP greater than 12 months and 9 (19.5%) a TTP greater than 18 months. Sixteen patients (34.8.%) survived more than 2 years and 2 (4.3%) survived more than 5 years. One patient was still alive and free from progression more than 7 years after starting treatment. Conclusions: This Phase II trial with a long-term follow-up revealed that some patients with hormone refractory prostate cancer could obtain durable disease response and long survival with an oral etoposide and estramustine combination regimen.