ERBB2 and breast cancer: Because optimal anthracycline and taxane-based chemotherapy schedules also reduce the risk of breast cancer mortality by about a third, regardless of HER2 status or other characteristics,12, 17 the combination of chemotherapy plus trastuzumab for HER2-positive breast cancer could reduce the risk of death from breast cancer by about 50%, compared with receiving neither chemotherapy nor trastuzumab.