Notably, patients with clinical stage T1aN0 or T1bN0 HER2-positive tumors may not need neoadjuvant therapy and may be candidates for upfront surgical management followed by trastuzumab/paclitaxel, as established by the adjuvant phase 2 APT trial for node-negative HER2-positive breast cancer. This evidence concerns the gene ERBB2 and breast carcinoma.