Phase II study of high dose epirubicin in combination with cyclophosphamide in patients with advanced breast cancer.

Background: Combination chemotherapy for metastatic breast cancer will palliate symptoms in the majority of patients but only a small percentage will have prolonged survival. Higher doses of doxorubicin lead to increased response rates in breast cancer and early studies have shown that epirubicin could be tolerated in higher doses with less relative toxicity than doxorubicin.
Aims: This study was initiated to assess the dose of epirubicin that could be tolerated by escalating its dose while maintaining a fixed dose of cyclophosphamide. Simultaneously tumour response rate, spectrum of toxicities, duration of response and overall survival in patients with metastatic breast cancer were assessed.
Methods: Patients with metastatic breast cancer commenced chemotherapy with a starting dose of epirubicin of 120 milligram per metre squared (mg/m2) and cyclophosphamide 600 mg/m2. The dose of epirubicin was to be escalated or reduced depending on toxicity.
Results: Forty female patients were entered into this study and three patients withdrew because of toxicity. Overall tumour response rate was 75% with 27.5% of patients obtaining a complete response. Median time to progressive disease was 35 weeks and median overall survival was 48 weeks, with median survival for complete responders being 103 weeks. Thirty-one (77%) patients completed five or more courses of treatment. Haematological toxicity was the main side effect and 70% of patients required a dose reduction. No patients were eligible for a dose escalation. One patient died as a consequence of neutropenic sepsis. Four (10%) patients had treatment ceased because of decrease in left ventricular ejection fraction and one patient died as a consequence of heart failure. Four patients remain alive.
Conclusions: High dose epirubicin combined with cyclophosphamide is an effective treatment regimen for metastatic breast cancer obtaining higher overall response rates with increased percentage complete responses compared to conventional dose chemotherapy. Although toxicity was increased, high dose chemotherapy was well tolerated and mortality associated with treatment was not increased. No dose escalations of epirubicin were possible and a dose of 90 mg/m2 of epirubicin would be the maximum dose when used in combination with cyclophosphamide. Further trials are required to determine the influence of this high dose therapy on survival duration and whether comparable benefits can be achieved with shorter durations of therapy.