Randomized phase II study of docetaxel plus estramustine and single-agent docetaxel in patients with metastatic hormone-refractory prostate cancer

Background: Docetaxel (faxotere (R))-based regimens are the new standard therapy in advanced hormone-refractory prostate cancer (HRPC). A synergistic activity has been shown with docetaxel in combination with estramustine in vitro; however, the benefit of this combination remains controversial in clinical practice. We assessed the activity and safety of docetaxel alone and docetaxel-estramustine in HRPC. Patients and methods: Patients (n = 92) with metastatic HRPC and rising prostate-specific antigen (PSA) while receiving androgen suppression were randomized to 3-weekly treatment with either docetaxel 75 mg/m(2), day 1 (D), or docetaxel 70 mg/m2, day 2, plus oral estramustine 280 mg twice daily, days 1-5 (DE). Results: Ninety-one patients were treated (DE 47, D 44). A PSA response occurred in 68% (primary endpoint met) and 30% of patients, respectively. Median PSA response duration was 6.0 months in both groups. Median time to progression was 5.7 and 2.9 months, and median survival was 19.3 and 17.8 months in the DE and D arms, respectively. Hematologic and non-hematologic toxic effects were mild and similar in both arms. One patient in each group withdrew due to toxicity. Quality of life was similar in both groups. Conclusion: Combining estramustine with docetaxel in this schedule is an active and well-tolerated treatment option in HRPC.