Cardiac Complications of HER2-Targeted Therapies in Breast Cancer

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer is associated with aggressive disease and a poor prognosis. There are a number of anti-HER2 therapies currently available and more in development. Cardiac concerns raised by early experience with HER2 inhibitor trastuzumab had led to subsequent trial designs focused on a more selective patient population with a lower cardiac risk, generally with a median age of 50-55 years old, with a normal left ventricular ejection fraction (LVEF) at study entry, and with no clinical cardiovascular disease or uncontrolled cardiac risk factors. Within this context, the cardiac safety profile of the agents outlined in this review appears to be quite acceptable and thus the risk to benefit ratio is favorable. Given the theoretical cardiac concerns of this class of cancer therapeutics that prompted the stringent patient selection and eligibility criteria in clinical trials, clinicians should exercise reasonable caution and monitor patients carefully for cardiac sequelae when using these agents outside of the controlled conditions applied in the clinical trials.