Purpose: The role of high-dose chemotherapy (HDCT) in metastatic breast cancer remains controversial. Trials with late intensification HDCT have failed to show an advantage in overall survival. This study was initiated to compare up-front tandem HDCT and standard combination therapy in patients with metastatic breast cancer.
Patients and methods: Patients without prior chemotherapy for metastatic disease were randomly assigned to standard combination therapy with doxorubicin and paclitaxel (AT) or double HDCT with cyclophosphamide, mitoxantrone, and etoposide followed by peripheral-blood stem-cell transplantation. HDCT was repeated after 6 weeks. Patients were stratified by menopausal and hormone-receptor status. The primary objective was to compare complete response (CR) rates.
Results: A total of 93 patients were enrolled onto the trial. Intent-to-treat CR rates for patients randomized to HDCT and AT were 12.5% and 11.1%, respectively (P = .84). Objective response rates were 66.7% for patients in the high-dose group and 64.4% for patients in the AT arm (P = .82). In an intent-to-treat analysis, there were no significant differences between the two treatments in median time to progression (HDCT, 11.1 months; AT, 10.6 months; P = .67), duration of response (HDCT, 13.9 months; AT, 14.3 months; P = .98), and overall survival (HDCT, 26.9 months; AT, 23.4 months; P = .60). HDCT was associated with significantly more myelosuppression, infection, diarrhea, stomatitis, and nausea and vomiting, whereas patients treated with AT developed more neurotoxicity.
Conclusion: This trial failed to show a benefit for up-front tandem HDCT compared with standard combination therapy. HDCT was associated with more acute adverse effects.