Maintenance Trastuzumabplus Letrozoleafter Complete Response to Trastuzumab-Emtansine in a Patient with HER2- Positive, Hormone Receptor Positive Metastatic Breast Cancer

Although metastatic breast cancer overexpressing Human Epidermal Growth Factor Receptor-2 (HER2) is a not curable disease, the introduction of HER2-targeted agents, including trastuzumab, pertuzumab, trastuzumab-emtansine and lapatinib, has significantly improved...