Use of non-anthracycline regimens in early stage breast cancer in Australia

Abstract

Various factors have recently prompted a re-evaluation of the role of non-anthracycline regimens in early stage breast cancer (ESBC). Since 1990 anthracyclines have been a key component of chemotherapy regimens. However, there is increased understanding of the long-term, irreversible toxicities associated with these therapies, including cardiac failure and secondary leukemia. The development of the taxanes in the 1990s led to new adjuvant chemotherapy regimens and trials of various combinations in an effort to further increase survival and reduce toxicity. Concerns about cardiac toxicity were reinforced with the emergence of trastuzumab for the treatment of HER2-positive breast cancer. Trastuzumab alone causes cardiac toxicity and increases the risk of cardiac toxicity when combined with anthracyclines. These data, combined with recent results demonstrating the efficacy of non-anthracycline regimens in various disease settings, have generated interest in utilizing these therapies in patients with both HER2-positive and -negative tumors. This review outlines the evidence for the use of non-anthracycline adjuvant regimens in ESBC, including cyclophosphamide, methotrexate and 5-fluoruoracil, docetaxel, carboplatin and trastuzumab and docetaxel and cyclophosphamide, which have demonstrated equivalent efficacy and reduced toxicity compared to anthracycline-based regimens in various trials. The review also examines evidence for the use of non-anthracycline regimens in patients who previously had restricted access to these therapies due to their negative lymph node status. The wider availability of these regimens increases options when deciding upon adjuvant chemotherapy for patients with ESBC, especially in patients with a high risk of cardiac toxicity.