Background: The cross-over resistance between different anthracyclines in breast carcinoma has not been largely evaluated in clinical trials.
Patients and methods: Nineteen patients with metastatic breast cancer who had failed prior first line FEC chemotherapy (fluorouracil 500 mg/m2, epirubicin 50 mg/m2 cyclophosphamide 500 mg/m2, every 4 weeks) were treated with a combination of fluorouracil 500 mg/m2, doxorubicin 50 mg/m2 and cyclophosphamide 500 mg/m2 every 4 weeks (FAC).
Results: Five patients achieved partial responses, ranging in duration from 5 to 8 months. The main toxicity was cardiac, with congestive heart failure documented in five patients.
Conclusion: The findings indicate an absence of cross resistance of doxorubicin in some epirubicin-resistant patients.