A Study of Surgery and Radiotherapy in People With Breast Cancer

Prior to randomization, patients will receive standard of care first-line systemic therapy as defined by NCCN guidelines (paclitaxel, trastuzumab and pertuzumab at the time of study activation). Following a 3-12 month period without evidence of progression as determined by the treating clinician, patients may be registered and then randomly assigned in 1:1 fashion to one of two study arms. All patients will be followed until progression of disease or 3 years after randomization, whichever comes first. All HER2-directed agents are FDA-approved and administered per standard of care practice.