Trastuzumab (Herceptin; Roche, Basel, Switzerland) is a humanized mouse monoclonal antibody that specifically blocks the activity of HER2, which has been shown to improve both disease-free and overall survival in node-positive and high-risk node-negative HER2+ breast cancer patients.[5] However, there are much fewer reports concerning the locoregional benefit of trastuzumab. Here, ERBB2 is linked to breast cancer.