Pyrotinib Plus Neoadjuvant Chemotherapy in HR+/HER2-, HER4-High Breast Cancer

Inclusion Criteria: * Presenting with histological(by core needle biopsy or by limited incisional biopsy) proven hormone receptor positive (ER≥10% and/or PR ≥1%), HER2 negative(IHC ≤2+ and/or FISH-) , stage II/ III breast cancer. * Have clinical indication for neoadjuvant therapy. * HER4 IHC score ≥ 4. * Measurable disease (breast and/or lymph nodes). * The Eastern Cooperative Oncology Group (ECOG) performance status must be 0 or 1. * Adequate bone marrow function (within 4 weeks prior to registration): WBC≥3.0x109/l, neutrophils ≥1.5 x 109/l, platelets ≥100 x 109/l. * Adequate liver function (within 4 weeks prior to registration): bilirubin ≤1.5 x upper limit of normal (UNL) range, ALAT and/or ASAT ≤2.5 x UNL, Alkaline Phosphatase ≤5 x UNL. * Adequate renal function (within 4 weeks prior to registration): the calculated creatinine clearance should be ≥50 ml/min. * Patients must have the ability to swallow oral medication. * Without history of any kind of treatment to known malignancy (solid tumor or hematologic). * Written informed consent. * Accessible for treatment and follow-up. Exclusion Criteria: * Evidence of stage IV breast cancer. * Contralateral invasive breast cancer or Inflammatory breast cancer. * History of non-breast malignancies (except for in situ cervical cancers, basal cell carcinoma of the skin, squamous cell carcinomas of the skin or thyroid papillary carcinoma that had received curative treatment before enrollment) within 5 years prior to randomizatio…