⁃ Aged 18-70 years old. Histologically confirmed HER2-positive invasive breast cancer with clinical stages T1c-4, N0-3, and M0 (excluding T1cN0M0), according to the 8th American Joint Committee on Cancer (AJCC) edition BC staging system HER2 overexpression was defined as immunohistochemistry (IHC) 3+ or 2+ with HER2 gene amplification, determined by fluorescence in situ hybridization (FISH).

⁃ Baseline left ventricular ejection fraction (LVEF) of ≥50%. Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1.

⁃ The functional level of major organs must meet the following requirements (no blood transfusion and no use of white blood cell, red blood cell and platelet-raising drugs within 2 weeks before the first dose):

• Absolute neutrophil count ≥ 1,500/mcL

• Platelets ≥ 100,000/mcL

• Hemoglobin ≥ 9.0 g/dL

• Total bilirubin ≤ 1.5 x upper limit of normal (ULN)

• Alanine aminotransferase and aspartate aminotransferase (ALT/AST) ≤1.5×ULN

• Blood urea nitrogen and serum creatinine ≤1.5×ULN

• Creatinine clearance (Ccr) ≥50 ml/min (Cockcroft-Gault formula) Signature of informed consent