Single-agent docetaxel in metastatic breast cancer patients pre-treated with anthracyclines and paclitaxel: Partial cross-resistance between paclitaxel and docetaxel

The purpose of this study was a retrospective analysis of docetaxel in a cohort of anthracyclines and paclitaxel pretreated patients with metastatic breast cancer. From July 1998 to June 1999, 24 consecutive patients were included for this study. The regimen consisted of docetaxel 75 mg/m² in combination with a 3-day schedule of dexamethasone every 3 weeks until disease progression or unacceptable toxicity. The median age of patients was 53 (ranged 32-67) years with a median performance status of 2. Twenty of the 24 patients (84%) had measurable disease. The median number of organs involved was 2 (range 1-4). A total of 146 cycles chemotherapy were given with a mean of 6. There was a 25% (six of 24) overall response rate including one complete response, 37.5% stable disease and 37.5% progressive disease. The major toxicity included grade 3-4 leukopenia (41.7%) and eight episodes of infection. No treatment-related death was observed. The responders included patients refractory to or resistant to prior paclitaxel treatment. The median survival and median time to disease progression was 12 and 9 months, respectively. We conclude that docetaxel has a modest activity in breast cancer patients pre-treated with anthracyclines and paclitaxel, indicating a partial crossresistance between paclitaxel and docetaxel. (C) 2000 Lippincott Williams and Wilkins.