ERBB2 and breast cancer: 1. Age ≥18 years old2. Diagnosed as HER2-positive breast cancer3. Surgically operable, locally advanced, or inflammatory HER2-positive (immunohistochemistry 3+ or in situ hybridization positive) breast cancer at stages II to IIIC, characterized by a primary tumor diameter exceeding 2 cm or the presence of lymph node involvement.4. The ECOG performance status score is 0 or 15. The baseline left ventricular ejection fraction (LVEF) was evaluated within 3 months preceding enrollment and was found to be greater than 55%6. No history of severe hepatic, renal, or hematological disorders