Epirubicin and Long-Term Heart Failure Risk in Breast Cancer Survivors

This article refers to ‘Long-term effect of epirubicin on incidence of heart failure in women with breast cancer: insight from a randomized clinical trial’ by A. Banke et al., published in this issue on pages 1447–1453. The advent of anthracycline therapy in the 1960s for cancer treatment was followed by observations of dose-dependent cardiotoxicity and heralded the establishment of the sub-specialty of ‘cardio-oncology’.1 In the treatment of breast cancer, anthracyclines are expected to continue to be part of cancer therapy regimens for the foreseeable future with epirubicin and doxorubicin being the preferred agents in Europe and the United States, respectively.2 Successes in breast cancer treatment have resulted in nearly 80% of patients surviving at 15-year follow-up3; as such, cardiovascular (CV) surveillance and disease prevention will be a cornerstone of cancer survivorship amongst breast cancer patients.2 The short-term incidence of heart failure (HF) after very high-dose epirubicin exposure (∼900 mg/m2) may exceed 5–10%, but substantial cardiotoxicity may occur at lower doses depending on background co-morbid disease burden and individual susceptibility.4,5 The long-term CV sequelae of epirubicin treatment is less established and has largely been informed by observational studies. Clinical trials have been limited to smaller sample sizes with short follow-up and have traditionally focused on left ventricular ejection fraction as a surrogate marker of cardiotoxic risk. We discuss strategies of ascertainment of high-quality data regarding chemotherapy-related risks of HF in future clinical trials of cancer therapies.