Background: Metastatic breast cancer remains incurable with conventional chemotherapy. For any specific chemotherapy, higher dose intensity may be achieved with either increased doses per cycle, or shortened intervals between courses, or both. We demonstrate here the feasibility and encouraging results of a high-dose combination regimen administered every two weeks.
Patients and methods: Women with metastatic breast cancer were treated every 14 days for 6 courses with 75 mg/m2 epirubicin and 1200 mg/m2 cyclophosphamide, followed by conventionally-delivered (q 3-4 weeks) chemotherapy. The treatment was to be resumed regardless of the neutrophil count, except in instances of febrile neutropenia. Prophylactic oral antibiotherapy was given, while hematopoietic growth factors and stem cell support were not employed.
Results: Eighty-six patients were treated between May 1986 and June 1995. Their median age was 43 years (26-69). Grade 3-4 neutrophil toxicity was observed after 86% of the courses, resulting in febrile neutropenia in 5%-18% of the patients, and the rehospitalization of 5%-10%. The median given/planned dose intensity was 97% (79-106). The objective response rate in 84 evaluable patients was 54% (95% confidence interval (95% CI): 43-65), with a complete response rate of 11%, and a 14% rate of outright progression. Median progression-free survival was 16 months and median overall survival 32 months. Multivariate analysis retained previous adjuvant chemotherapy as a negative survival prognostic factor.
Conclusions: This dose-intensive anthracycline-based regimen is feasible with manageable morbidity despite pronounced myelotoxicity, and yields encouraging survival rates.