Monthly paclitaxel and carboplatin with oral estramustine phosphate in patients with hormone-refractory prostate cancer

Background We aimed to determine the safety and efficacy of monthly paclitaxel and carboplatin with oral estramustine phosphate in patients with hormone-refractory prostate cancer (HRPC). Methods Patients with prostate cancer that was progressing despite androgen ablation therapy were treated with i.v. paclitaxel, 175 mg/m², over 3 h, followed by carboplatin (area under the curve, 5) on day 1, with oral estramustine phosphate, 280 mg twice daily, for a 28-day treatment cycle. Estramustine phosphate was precluded in those patients who had experienced adverse effects during prior chemotherapies. Patients were evaluated for response every cycle, and the treatment was continued until the cancer progressed. Results Twenty-one patients with progressive hormone-refractory disease were treated for a median of 4 cycles (range, 1 to 11 cycles). Estramustine phosphate was precluded in seven patients. Post-therapy decreases in serum prostate-specific antigen levels of 50% and 75%, respectively, were seen in 43% and 19% of the patients (95% confidence intervals, 22% to 64% and 2% to 36%). Of the nine patients with measurable disease, 1 (11%) had a complete response and 2 (22%) had a partial response. The overall median time to progression was 4 months, and the median survival time for all patients was 11 months. Major grade 3 or 4 adverse effects were anemia (29%), neutropenia (48%), and thrombocytopenia (24%). Mild peripheral neuropathy and myalgia/arthralgia were observed in 11 (52%) and 9 (43%) patients, respectively. Conclusion Monthly paclitaxel and carboplatin with oral estramustine phosphate has significant antitumor activity and is well tolerated in patients with progressive HRPC.