Purpose: To determine the efficacy (objective response rate and duration of response and survival) and toxicity of docetaxel in patients with strictly defined anthracycline-resistont metastatic breast cancer (MBC). Patients and Methods: Thirty-five patients with bidimensionally measurable MBC who had progressive disease while receiving anthracycline-containing chemotherapy were registered onto the phase II trial, Docetaxel wets administered at a dose of 100 mg/m(2) over 1 hour every 21 days. Results: Thirty-four patients were assessable for disease response; 18 (53%; 95% confidence interval [CI], 35% to 70%) achieved a partial response, The median times to disease progression and survival duration were 7.5 and 13.5 months, respectively, for responding patients. The median overall survival duration was 9 months, Two hundred eight cycles (median, five) of docetaxel were administered. Neutropenia with less than 500 cells/mu L developed in 31 of 35 patients; it was complicated by fever in 30 (14%) of 208 cycles and in 18 (51%) of 35 patients, including one treatment-related death, Fluid retention was seen in 15 (43%) of 35 patients, including pleural effusions in 11 patients (31%). Moderate skin toxicity, asthenia, and myalgia were observed in 16%, 58%, and 37% of cycles, respectively. Conclusion: Docetaxel has the highest reported anti-tumor activity in anthracycline-resistant MBC. High objective response rates were seen in patients with visceral-dominant involvement, multiple metastatic sites, or extensive previous therapy, Docetaxel is associated with severe bur reversible neutropenia, asthenia, and cumulative dose-related fluid retention. Dexamethasone decreased the frequency and severity of skin toxicity and appeared to ameliorate fluid retention. (C) 1995 by American Society of Clinical Oncology.
