Adjuvant Study of Pyrotinib in HER-2 Positive Breast Cancer

Inclusion Criteria: * Female, Aged ≥18 and ≤70 years; * Histologically confirmed invasive HER2 positive breast cancer, early disease(Stage ⅡA-Ⅲ) ; * Completed neoadjuvant therapy, including chemotherapy and trastuzumab; * Residual invasive disease was detected pathologically in the surgical specimen of the breast or axillary lymph nodes after completion of neoadjuvant chemotherapy; * Been or being treated for early breast cancer with standard of care duration of trastuzumab; * Adjuvant treatment regimen needs to be determined before randomization; * Duration from Random time to the last use of trastuzumab≤1 year. * Performance Status- Eastern Cooperative Oncology Group (ECOG) 0-1; * Required laboratory values including following parameters:ANC: ≥ 1.5 x 109/L; Platelet count: ≥ 100 x 109/L; Hemoglobin: ≥ 9.0 g/dL; Total bilirubin: ≤ 1.5 x upper limit of normal, ULN; ALT and AST: ≤ 1.5 x ULN; BUN and creatine clearance rate: ≥ 50 mL/min; LVEF: ≥ 50%; QTcF: \< 470 ms * Signed informed consent form (ICF) . Exclusion Criteria: * Metastatic disease (Stage IV) ; * Gross residual disease remaining after mastectomy or positive margins after breast-conserving surgery; * Progressive disease during neoadjuvant therapy; * Subjects that are unable to swallow tablets, or dysfunction of gastrointestinal absorption; * Treated or treating with anti-HER2 TKI, including but not limited to pyrotinib, lapatinib and neratinib. * Less than 4 weeks from the last clinical trial; * History of immunodeficiency, including HIV-positive, suffering from other acquired, congenital immunodeficiency disease, or history of organ transplantation; * Subjects had any heart disease, including: (1) angina; (2) requiring medication or clinically significant arrhythmia; (3) myocardial infarction; (4) heart failure; (5) Any heart diseases judged by investigator as unsuitable to participate in the trial; * Female patients who are pregnancy, lactation or women who are of childbearing potential tested positive in baseline pregnancy test;Female patients of childbearing age that are reluctant to take effective contraceptive measures throughout the trial period; * Evidence of significant medical illness that in the investigator's judgment will substantially increase the risk associated with the subject's participation in and completion of the study.