Do anthracyclines still have a role in adjuvant chemotherapy of breast cancer?

Anthracycline-based regimens became the standard of care for early breast cancer patients based on the survival advantage they provide over nonanthracycline-containing regimens. The addition of taxanes, and subsequently trastuzumab in HER2-overexpressing patients, to anthracyclines further improved their efficacy in several studies involving high-risk early breast cancer patients. Concern over toxicity initially surfaced after anthracyclines were reported to carry an increased risk of cardiotoxicity and secondary leukemia. Trastuzumab has since been shown to compound the risk of cardiotoxicity in patients who have received an anthracycline. This has led to the development of regimens featuring a taxane without an anthracycline; these protocols vary in design and have different toxicity and efficacy profiles. Ongoing investigations are centered on the optimization of nonanthracycline regimens, prospective exploration of molecular markers to identify populations of patients who will derive maximal benefit from anthracycline-based chemotherapy, and the identification of less cardiotoxic formulations of existing anthracycline agents. Perhaps most importantly, a rapidly growing understanding of the biological heterogeneity of breast cancer is likely to lead to an individualized standard of care guided by particular patient and tumor characteristics.