Phase II trial of estramustine phosphate and oral etoposide in patients with hormone-refractory prostate cancer

Background: There is a need for active agents with a bettersafety profile than docetaxel, yet good activity, for patientswith hormone-refractory prostate cancer (HRPC). We carried outa phase II trial to determine the activity and safety of estramustineplus oral etoposide in HRPC. Patients and methods: Patients were given estramustine (280mg twice daily) and etoposide (100 mg/day, days 1–21)in 28-day cycles until disease progression or unacceptable toxicity.Primary end points were overall response rate and safety, asdetermined by prostrate-specific antigen (PSA) levels and lesionassessment. Results: From November 2001 to February 2007, 75 patients wereenrolled. All patients were assessable for safety; 17 (22.6%)had grade 3/4 toxicity. PSA response was assessable in 69, 14of whom had a >50% reduction in PSA. Of 10 patients withone or more measurable lesions, two (20%) had partial responseand two (20%) disease stabilization. Overall, median time toprogression was 4.4 months (range 1 week–43 months); mediansurvival was 23 months (range 3 weeks–64+ months). Conclusions: Estramustine plus etoposide is active and has amanageable safety profile in patients with HRPC. In asymptomaticpatients with nonaggressive disease this combination could beuseful to delay the start of more demanding treatments. Key words: estramustine phosphate, etoposide, hormone-refractory prostate cancer