Single-agent gemcitabine is active in previously treated metastatic breast cancer

This phase II study was designed to assess the efficacy and safety of gemcitabine in patients with metastatic breast cancer (MBC) previously treated with an anthracycline- or anthracenedione-containing regimen as first-line therapy for metastatic disease.

Forty-seven patients with MBC were enrolled in five French centers. Patients were eligible if they had received one prior chemotherapy regimen with an anthracycline or anthracenedione for metastatic disease, if they had responded to that prior regimen, and if they had relapsed at least 6 months after the first response. Fifteen patients received more than one prior anthracycline regimen; thus, gemcitabine was third-line therapy for 30% of patients. Gemcitabine 1,200 mg/m(2) was administered as a 30-min intravenous infusion on days 1, 8, and 15 of a 28-day cycle for a maximum of eight cycles after the best response was obtained.

Objective responses were seen in 12 of 41 assessable patients (4 complete responses and 8 partial responses), for an objective response rate of 29% (95% confidence interval, 16-46%). The median response duration was 8.1 months (range: 2.5-27.4 months). Serious hematological toxicity was minimal, with grade 4 neutropenia in 2% of the patients (no neutropenic fever), grade 3 neutropenia in 28% of the patients, and grade 3 thrombocytopenia in 6% of the patients. Among the nonhematological toxicities, asthenia was the most common.

Gemcitabine given at this dose and schedule is a well-tolerated treatment with definitive antitumor activity in pretreated MBC patients. This result warrants future exploration of the use of gemcitabine as a single agent and in combination in patients with MBC.