ERBB2 and breast cancer: Trastuzumab improves survival endpoints and quality of life for patients with advanced HER2-positive breast cancer undergoing chemotherapy.75 Trastuzumab was the first target approved specifically for early stage HER2-positive breast cancer in combination with cytotoxic agents, such as taxane, after completion of doxorubicin therapy.82,83 In addition, trastuzumab is recommended by both St.