Docetaxel in Patients with Anthracycline-Resistant Advanced Breast Cancer

Objective: To better determine docetaxel activity in patients with well-defined anthracycline-resistant breast cancer. Methods: From October 1996, we carried out a phase II trial in 69 heavily pretreated patients with advanced breast cancer with docetaxel 100 mg/m 2 by a 1-hour infusion on day 1, with cycles repeated every 3 weeks. Patients were classified as having primary anthracycline resistance (n = 32), secondary anthracycline resistance (n = 7), anthracycline pretreatment (n = 22) or no anthracycline pretreatment (n = 8). Results: Among 68 evaluable patients, we observed 6 (9%) complete responses and 27 (40%) partial responses, for an overall response rate of 49% (95% confidence interval 37–61%); the disease remained stable in 17 patients (25%). Responses according to the above subgroups were as follows: primary anthracycline resistance 41%, secondary anthracycline resistance 43%, anthracycline pretreatment 64% and no anthracycline pretreatment 43%. The median time to response, median time to progression and median overall survival were 2, 7 and 10 months, respectively. Myelosuppression was the dose-limiting toxicity, with grade 4 neutropenia occurring in 47% of the patients and neutropenic fever in 12%. G-CSF was added in the case of grade 4 febrile neutropenia; a 25% reduction in the dose of docetaxel was required in 4 patients. Other side effects were mild. Conclusions: The results of the present trial confirm the high activity of docetaxel in heavily pretreated patients with advanced breast cancer, including those with strictly defined anthracycline resistance.