Docetaxel in patients with anthracycline-resistant advanced breast cancer

To better determine docetaxel activity in patients with well-defined anthracycline-resistant breast cancer.

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).

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.

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.