Phase III Trial Comparing Three Doses of Docetaxel for Second-line Treatment of Advanced Breast Cancer

Purpose: To evaluate whether a relationship exists between docetaxel dose and clinical response in the treatment of patients with advanced breast cancer.

Patients And Methods: Patients whose cancer had progressed after one prior chemotherapy regimen for advanced breast cancer or had recurred during or within 6 months of adjuvant chemotherapy were randomly assigned to docetaxel 60, 75, or 100 mg/m2 intravenously every 3 weeks.

Results: Five hundred twenty-seven patients were randomly assigned (intent to treat [ITT]), and 524 were assessable for toxicity. In the population assessable for efficacy (n = 407), logistic regression analysis showed that increasing docetaxel dose was significantly associated with higher response rate (P = .007) and improved time to progression (TTP; P = .014). In the ITT analysis, a significant dose-response relationship was observed for tumor response (P = .026) but not for TTP (P = .067). The incidences of most hematologic and nonhematologic toxicities were related to increasing dose, with grade 3 to 4 neutropenia occurring in 76.4%, 83.7%, and 93.4% and febrile neutropenia occurring in 4.7%, 7.4%, and 14.1% of patients administered the 60, 75, and 100 mg/m2 doses, respectively. One death was considered treatment related.

Conclusion: A relationship between increasing dose of docetaxel and increased tumor response was observed across the dose range of 60 to 100 mg/m2 every 3 weeks. Toxicities were related to increasing dose. Depending on the therapy goal, any of the doses studied may be appropriate for second-line treatment of advanced breast cancer.