Pilot Trial of Adjuvant Paclitaxel Plus Estramustine in Resected High-Risk Prostate Cancer

Objectives: To determine the feasibility and toxicity of adjuvant paclitaxel plus estramustine in prostate cancer patients at high risk of a 2-year PSA failure after prostatectomy. Methods: Patients with prostate adenocarcinoma who underwent radical prostatectomy with at least a 50% probability of PSA failure at 2 years postprostatectomy received 4 cycles of paclitaxel 90 mg/m² by 1-hour infusion, weekly for 3 weeks, followed by a 1-week treatment rest. Patients received estramustine phosphate 140 mg orally 3 times daily on the day before, the day of, and the day after paclitaxel administration. Patients received warfarin 1 mg daily to prevent thromboembolism. Serum PSA was measured monthly during adjuvant therapy, then every 3 months for a minimum of 2 years. Results: Between December 2001 and September 2004, 17 patients underwent radical prostatectomy and received protocol treatment at the University of Pennsylvania. The median risk of a 2-year PSA failure was 70%. Five (30%) patients had PSA failure develop after radical prostatectomy. The median time to PSA failure was 19 months. A statistically significant difference (P = 0.001) was noted between the expected rate of PSA failure (0.70) and the actual rate of PSA failure (0.30). Grade 3 to 4 toxicities were uncommon and included thromboembolism (6%) and neutropenia (6%). All patients completed 4 cycles of therapy and there were no treatment related deaths. Conclusions: The adjuvant use of paclitaxel and estramustine in resected high-risk prostate cancer patients is feasible and well tolerated. Adjuvant cytotoxic chemotherapy deserves further investigation with randomized studies.