Phase II trial of docetaxel: a new, highly effective antineoplastic agent in the management of patients with anthracycline-resistant metastatic breast cancer.

PURPOSE: To determine the efficacy (objective response rate and duration of response and survival) and toxicity of docetaxel in patients with strictly defined anthracycline-resistant 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 was administered at a dose of 100 mg/m2 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/microL 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 antitumor 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 but reversible neutropenia, asthenia, and cumulative dose-related fluid retention. Dexamethasone decreased the frequency and severity of skin toxicity and appeared to ameliorate fluid retention.