Patient description: The patient is a 45-year-old postmenopausal woman with cytologically confirmed breast cancer. A core biopsy revealed a 3 cm invasive ductal breast carcinoma in the left upper outer quadrant. The tumor is HER2-positive and ER/PR negative. Axillary sampling revealed 5 positive lymph nodes. CXR was remarkable for metastatic lesions. The patient is using multivitamins and iron supplements. She does not smoke or consume alcohol. She is not sexually active and has no children. She is a candidate for tumor resection and agrees to do so prior to chemotherapy.

Clinical trial eligibility criteria: eligible ages (years): 18.0-65.0,  Breast Cancer,Her2 Positive 18 years ≤ age ≤ 75 years, Performance Status Eastern Cooperative Oncology Group (ECOG) 0-1 2. Clinical T2-T4d, or T1c with axillary LN+ 3. HER2 + invasive breast cancer confirmed by histopathology Note: HER2 expression positive refers to the tumor cells with immunohistochemical staining intensity of 3 + or confirmed positive by fluorescence in situ hybridization [fish] at least once during the pathological detection/review of primary tumor in the Department of pathology of participating research center hospital 4. Clinically measurable lesions: measurable lesions revealed by ultrasound, molybdenum target or MR (optional) within 1 month before randomization 5. Organ and bone marrow function test within one month before chemotherapy showed no chemotherapy contraindication Absolute value of neutrophil count ≥ 2.0×10^9 / L Hemoglobin ≥ 100g / L Platelet count ≥ 100×10^9 / L Total bilirubin < 1.5 ULN (upper limit of normal value) Creatinine < 1.5 × ULN AST/ALT < 1.5×ULN 6. Echocardiography: left ventricular ejection fraction (LVEF ≥ 55%) 7. For women of childbearing age, serum pregnancy test was negative 14 days before randomization 8. KPS score ≥ 80 points 9. Signed the informed consent form prior to patient entry  Metastatic disease (Stage IV) 2. Chemotherapy, endocrine therapy, targeted therapy and reflexotherapy have been used for this disease 3. The patient had a second primary malignant tumor, except for the well treated skin cancer 4. Patients who had undergone major surgery unrelated to breast cancer within 4 weeks before enrollment, or had not recovered completely from such operations 5. Serious heart disease or discomfort, including but not limited to the following diseases History of heart failure or systolic dysfunction (LVEF < 50%) high risk uncontrolled arrhythmias such as atrial tachycardia, resting heart rate > 100 BPM, significant ventricular arrhythmias (e.g., ventricular tachycardia) or higher-level atrioventricular block (i.e., mobitz II second degree atrioventricular block or third degree atrioventricular block) angina pectoris requiring anti angina drugs Heart valve disease with clinical significance ECG showed transmural myocardial infarction Poor control of hypertension (systolic blood pressure > 180 mmHg and / or diastolic blood pressure > 100 mmHg) 6. Due to serious and uncontrollable other medical diseases, the researchers believe that there are chemotherapy contraindications 7. Those who have been known to have allergic history to the drug components of this regimen; have a history of immune deficiency, including HIV positive test, or have other acquired or congenital immunodeficiency diseases, or have a history of organ transplantation