ERBB2 and breast cancer: Among patients with HER2-positive early breast cancer who had residual invasive disease after completion of neoadjuvant therapy, the risk of recurrence of invasive breast cancer or death was 50% lower with adjuvant T-DM1 than with trastuzumab alone(free of invasive disease at 3 years was 88.3% in the T-DM1 group and 77.0% in the trastuzumab group) in KATHERINE trial (37).