Trastuzumab-Induced Cardiomyopathy.

Trastuzumab targets the human epidermal growth factor receptor 2 (HER2). Its overexpression occurs in 25% of breast cancers and is associated with aggressive tumor characteristics and poor prognosis in absence of targeted therapy. Trastuzumab dramatically improves HER2-positive breast cancer outcomes; however, its clinical use is associated with left ventricular dysfunction and heart failure. Patients receiving trastuzumab or other HER2-targeted therapies undergo routine cardiac function assessment. Holding and/or stopping trastuzumab treatment in the setting of left ventricular dysfunction is recommended. This article summarizes the role of trastuzumab in cancer treatment, the mechanisms of trastuzumab-induced cardiotoxicity, recent clinical investigations, and current controversies.