Primary results of NRG Oncology / NSABP B-43: Phase III trial comparing concurrent trastuzumab (T) and radiation therapy (RT) with RT alone for women with HER2-positive ductal carcinoma in situ (DCIS) after lumpectomy.

508Background: Preclinical studies report that T can boost RT effectiveness. The primary aim of this trial assessed the efficacy of concurrent T + RT vs RT alone in preventing recurrence of ipsilat...