Randomized Controlled Trial of Trastuzumab With or Without Chemotherapy for HER2-Positive Early Breast Cancer in Older Patients

RCT (n=275) found primary objective of non-inferiority for trastuzumab monotherapy was not met (3-year disease-free survival: 89.5% vs. 93.8% trastuzumab+chemotherapy;HR 1.36 95% CI,0.72-2.58;p=0.51).However, observed loss of survival without chemotherapy was < 1 month at 3 years

Journal of Clinical Oncology