Epirubicin versus doxorubicin: Which is the anthracycline of choice for the treatment of breast cancer?

Breast cancer is the most common malignancy in women in the United States. The addition of anthracyclines to adjuvant therapy regimens has resulted in improvement in overall survival of patients. The 2 most commonly used anthracyclines are doxorubicin and epirubicin. Comparison studies in the metastatic setting have shown that, at similar doses, these 2 anthracyclines provide similar response rates. However, their toxicity profiles differ somewhat. The major side effects of anthracyclines are cardiotoxicity and myelosuppression. The equimolar dose ratios of doxorubicin to epirubicin for myelosuppression and cardiotoxicity are 1:1.2 and 1:1.7-2.0, respectively. There have been many studies comparing different schedules and doses of anthracyclines in the adjuvant setting. However, direct comparisons between doxorubicin and epirubicin in early-stage breast cancer have not been performed to date. In this article, we are attempting to provide an overview of current use of doxorubicin and epirubicin in breast cancer.