This is an open label, phase III study evaluating the efficacy and safety of Pyrotinib in Combination With Trastuzumab and paclitaxel in patients HER2 Positive and lymph node negative invasive Breast Cancer

Inclusion Criteria:

• Females 18-70 years old;
• Pathological confirmed of stage I-II breast cancer: histologically confirmed that the longest diameter of invasive cancer is no less than 1cm and no more than 5cm and the lymph node is negative (N0);
• The pathological type of immunohistochemistry must meet the following conditions: HER-2 (3+) or HER-2 (0-2 +) with FISH detection is amplified;
• For patients with invasive lesions on both sides, if both lesions are HER-2 positive and meet the tumor size requirements, then can be enrolled;
• Has adequate organ function meeting the following criteria: (1) adequate bone marrow function: hemoglobin ≥ 90 g/L (no blood transfusion within 14 days); absolute neutrophil count ≥ 1.5 x 109 /L; platelet count ≥ 100 * 109 /L; (2)adequate liver and kidney function: Alanine Aminotransferase (ALT) ≤ 3×upper limit of normal (ULN), Aspartate Aminotransferase (AST) ≤ 3×ULN, Total Bilirubin (TBIL)≤ 1.5×ULN, serum creatinine ≤ 1×ULN#and with endogenous creatinine clearance rate of >50 ml/min (Cockcroft-Gault formula);
• LVEF>50%;
• The patient voluntarily joined the study, signed the informed consent form, had good compliance, and cooperated with the follow-up.

Exclusion Criteria:

• Has received neoadjuvant therapy (include chemotherapy, targeted therapy, radiotherapy or endocrine therapy;
• Has previous history of additional malignancy, with the exception of adequately treated basal cell carcinoma and cervical carcinoma in situ;
• Has metastic (Stage 4) breast cancer;
• Pregnant or breast feeding women, or women of childbearing age who cannot practice effective contraceptives;
• Patients participating in other clinical trials at the same time;
• Has severe organ dysfunction (cardiopulmonary liver and kidney) insufficiency, left ventricular ejection fraction (LVEF) < 50% (cardiac ultrasound); severe cardio cerebral vascular disease within the 6 months previous of randomization (such as unstable angina, chronic heart failure, uncontrolled hypertension with blood pressure>150/90mmHg, myocardial infarction, or cerebral blood vessel); diabetic patients with poor blood glucose control; patients with severe hypertension;
• Has severe or uncontrolled infection;
• Has a history of psychotropic substance abuse and were unable to abandon drug habits, or those with history of mental disorders;
• The researchers considered patients to be unsuitable for the study.