Phase II evaluation of early oral estramustine, oral etoposide, and intravenous paclitaxel combined with hormonal therapy in patients with high-risk metastatic prostate adenocarcinoma: Southwest Oncology Group S0032

Objectives: To assess the efficacy of a multiagent taxane-based chemotherapy combined with hormonal therapy in men with metastatic androgen-dependent prostate cancer in a multicenter, cooperative group, single-arm trial. Methods: A total of 41 patients with newly diagnosed metastatic prostate cancer involving both the axial and the appendicular skeletons or viscera were enrolled. Of the 41 patients, 35 were treated with combined androgen blockade and ≤4 cycles of oral estramustine (280 mg orally 3 times daily) and etoposide (50 mg/m² daily) for 14 days of each 21-day cycle, with paclitaxel (135 mg/m² intravenously within 1 hour) on day 2 of each cycle. Chemotherapy was started within 30 days of the initiation of hormonal therapy. The patients were followed up to determine the progression-free survival. Results: The 35 patients received a total of 126 cycles of chemotherapy, with 30 receiving all 4 cycles. The median progression-free survival for the evaluable population was 13 months (95% confidence interval 10-16), with a median overall survival of 38 months (95% confidence interval 28-49). The main toxicities were myelosuppression, with 9 patients experiencing grade 3 or greater neutropenia and 1 developing grade 4 thrombocytopenia. One patient died of neutropenic infection. Thrombosis embolism occurred 4 times (3 of grade 4 and 1 of grade 3), with 1 episode of grade 4 cardiac ischemia. Conclusions: The results of our study have shown that the administration of chemotherapy to this population is feasible, with moderate toxicity. Taxane-based chemotherapy did not demonstrate significant efficacy in this high-risk population of patients with a poor prognosis.