Trastuzumab and Cardiac Monitoring in Breast Cancer

Although HER2-positive breast cancer accounts for a minority (<20%) of breast malignancies, almost half (45%) of all breast cancers occur in women older than 65; thus, this patient population represents a large body of candidates for HER2-directed therapy. Given trastuzumab's potential for cardiac toxicity, its common coadministration with other cardiotoxic agents (e.g., anthracyclines), and the tendency for older women to accumulate cardiovascular comorbidities, cardiac monitoring has been recommended since trastuzumab's FDA approval. For example, the National Comprehensive Cancer Network guidelines recommend monitoring with echocardiogram or multiple-gated acquisition scans at baseline, 3, 6, and 9 months. How well do physicians abide by …