Neoadjuvant Chemotherapy Plus Pyrotinib and Trastuzumab for HER2-positive Breast Cancer (NEOTORCH-BREAST05)

Inclusion Criteria:

1. Female patients aged 18-75 years old; 2. ECOG score is 0-1 points; 3. Histologicallyconfirmed invasive cancer meets the following standards:

• T1N1-3M0 or T2-4N0M0

• All patients were pathohistologically confirmed as HER2+ breast cancer. HER2positivity was determined locally and defned as 3+ staining intensity byimmunohistochemistry or HER2 gene amplifcation by fuorescence in situ hybridizationaccording to the 2013 American Society of Clinical Oncology/College of AmericanPathologists guidelines.

4. The functional level of major organs must meet the following requirements (noblood transfusion, no use of leukocyte and platelet boosting drugs within 2weeks before screening):

5. Blood routine: Absolute neutrophil count (ANC) greater than 1.5 × 109/L;platelet count (PLT) greater than 75 × 109/L; Hemoglobin (Hb) is greater than 90g/L; Lymphocyte count ≥ 1.5 × 109/L

6. Blood biochemistry: Total bilirubin (TBIL) is less than 1.5 × ULN; Alanineaminotransferase (ALT) and aspartate (AST) levels are less than 1.5 × ULN;Alkaline phosphatase is less than 2.5 × ULN; Urea nitrogen/Urea (BUN/UREA) andcreatinine (Cr) are less than 1.5 × ULN.

7. Cardiac ultrasound: Left ventricular ejection fraction (LVEF) greater than 55%.

8. 12 lead electrocardiogram: The Fridericia corrected QT interval (QTcF) is lessthan 470 milliseconds 5. For female patients who have not yet reached menopauseor undergone surgical sterilization: during the treatment period and in thestudy treatment, the final use effective contraceptive methods for at least 6months after a single administration.

9. Voluntarily join this study, sign an informed consent form, have goodcompliance, and are willing to cooperate with follow-up.

Exclusion Criteria:

1. Stage IV breast cancer.

2. Inflammatory breast cancer.

3. Previously received anti-tumor treatment or radiation therapy for any malignanttumor, excluding those that have been cured malignant tumors such as cervicalcarcinoma in situ, basal cell carcinoma, or squamous cell carcinoma.

4. Simultaneously undergoing anti-tumor treatment in other clinical trials, includingbut not limited to chemotherapy, endocrine therapy, biological therapy, boneimprovement drug therapy, or immune checkpoint inhibitor therapy, etc.

5. The patient had undergone major surgical procedures unrelated to breast cancerwithin 4 weeks before the first administration of the study drug, or the patient hasnot fully recovered from such surgical procedures.

6. Serious heart disease or discomfort, including but not limited to the followingdiseases:

1. Diagnosed history of heart failure or systolic dysfunction (LVEF less than 50%).

2. High risk uncontrolled arrhythmias, such as atrial tachycardia, resting heart rategreater than 100bpm, significant ventricular arrhythmias (such as ventriculartachycardia), or higher-level atrioventricular block (i.e. Mobitz II second or thirddegree atrioventricular block).

3. Angina requiring medication for treatment. 4) Heart valve disease with clinicalsignificance. 5) ECG shows transmural myocardial infarction. 6) Poor control ofhypertension (systolic blood pressure greater than 180mmHg and/or diastolic bloodpressure greater than 100mmHg after drug treatment).

7. Uncontrolled active infections that require treatment; History of immunodeficiency,including HIV testing positive Sexual, or suffering from other acquired orcongenital immunodeficiency diseases, or having a history of organ transplantation.

8. Patients with chronic active hepatitis B or active hepatitis C (excluding hepatitisB virus carriers, stable hepatitis B after drug treatment [HBV-DNA test negativeor<50IU/ml] and cured hepatitis C patients [HCV RNA test negative]).

9. Individuals with a known history of allergies to the components of this medicationregimen.

10. Pregnant and lactating female patients, female patients with fertility and positivebaseline pregnancy test results, or reproductive age patients who are unwilling totake effective contraceptive measures during the entire trial period and within 6months after the last study medication.

11. Suffering from serious accompanying diseases or other comorbidities that mayinterfere with the planned treatment, or any other circumstances that the researcherdeems unsuitable for the patient to participate in this study.