Docetaxel vs doxorubicin in metastatic breast cancer resistant to alkylating chemotherapy

Abstract

Single-agent docetaxel (Taxotere) has been shown to be highly active in metastatic breast cancer, with an overall response rate of 47%, median time to progression of 4 months, and survival of 10 months when administered as second-line therapy. These data compare favorably with those reported for doxorubicin (Adriamycin), which has been considered the most active single agent in this setting. This nonblinded, multicenter, randomized phase III study compared the median time to progression, response rate, quality of life, toxicity, and survival after treatment with docetaxel or doxorubicin in patients with metastatic breast cancer in whom previous alkylating chemotherapy failed. Patients were randomized to receive an intravenous infusion of either docetaxel, 100 mg/m2, for 1 hour once every 3 weeks or doxorubicin, 75 mg/m2, for 15 to 20 minutes once every 3 weeks. This preliminary analysis presents data on 200 of 326 patients recruited. It was performed after the completion of patient accrual. The median time to progression was greater in the docetaxel group than in the doxorubicin group (29 vs 21 weeks, respectively; P = not significant). Overall response rates were higher with docetaxel (47% vs 27%), and fewer patients in the docetaxel group had progressive disease as their best overall response (10% vs 22%). Both regimens caused the same incidence and severity of neutropenia, yet patients treated with doxorubicin had a higher incidence of infection and febrile neutropenia. In addition, doxorubicin produced a higher incidence of grade 3 to 4 thrombocytopenia. Cardiac toxicity led to discontinuation in 7 patients and death in 2 patients in the doxorubicin group; fluid retention led to discontinuation in 1 patient in the docetaxel group. Based on this preliminary analysis, docetaxel was more active and safer than doxorubicin in patients with metastatic breast cancer in whom previous alkylating chemotherapy failed.