Phase II Multicenter Trial of a Weekly Paclitaxel and Carboplatin Regimen in Patients With Advanced Breast Cancer

Abstract

PURPOSE: To determine the activity of weekly paclitaxel plus carboplatin as first-line therapy in patients with advanced breast cancer (ABC) by assessing response rate, survival, and safety. PATIENTS AND METHODS: One hundred patients with ABC received paclitaxel 135 mg/m2 (group 1, n = 20) and carboplatin area under the concentration-time curve (AUC) of 2. Paclitaxel was subsequently reduced to 100 mg/m2 (group 2, n = 80) because of toxicity. The median age was 58.5 years, and most patients had an Eastern Cooperative Oncology Group performance status of ≤ 2. Estrogen and progesterone receptor status were evenly distributed among both groups. Sixty-one patients received prior chemotherapy, 37 (61%) of whom received prior doxorubicin. Among 47 patients who received prior hormonal therapy, 43 received tamoxifen. RESULTS: The overall response rate (ORR) among 95 assessable patients was 62%, including 8% complete responses and 54% partial responses. The median time to response was 1.8 months, and the median duration of response was 13.3 months. The median time to progression was 4.8 months. The median survival was 16 months. Neutropenia and leukopenia were the most common grade 3 and 4 toxicities. In group 1, neutropenia (50%) and leukopenia (35%) necessitated dose reductions for 50% of patients during the first three cycles, prompting the reduction in paclitaxel dose to 100 mg/m2. Grade 3 and 4 nonhematologic toxicities for all patients included peripheral neuropathy (11%), infection (6%), anemia (5%), weakness (6%), and paresthesia (3%). CONCLUSION: The 62% ORR achieved with weekly paclitaxel plus carboplatin is among the highest achieved with chemotherapy for ABC. This high response rate and the lack of cardiotoxicity suggest that the regimen should be considered as a nonanthracycline regimen for future adjuvant therapy.