Neoadjuvant Pyrotinib in HR-positive and HER2-low High-risk Early Breast Cancer

Inclusion Criteria: * Must participate voluntarily, sign the informed consent form, and have good compliance * Aged ≥ 18 and ≤ 70 years old with ECOG PS score of 0-1 * Histopathological newly diagnosed, unilateral, primary invasive breast cancer * Histopathological hormone receptor-positve ( estrogen receptor and/or progesterone receptor ≥ 10% stained cells) and HER2-low (immunochemistry 2+ with fluorescent in situ hybridization negative) * TNM stage-IIb/III, or TNM stage-IIa with high risk (N+, G3, or MammaPrint High-risk) * At least one evaluable target breast lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 * Left ventricular ejection fraction ≥ 55%, Fridericia-corrected QT interval \< 450 ms in males and \< 470 ms in females * White blood cell count: ≥ 3.0 × 10\^9/L, absolute neutrophil count: ≥ 1.5 × 10\^9/L, platelet count: ≥ 100 × 10\^9/L, hemoglobin: ≥ 90 g/L * Aspartate aminotransferase and alanine aminotransferase: ≤ 2.5 × ULN, alkaline phosphatase: ≤ 2.5 × ULN, blood total bilirubin: ≤ 1.5 × ULN, serum creatinine: ≤ 1.5 × ULN * Non-menopausal or non-surgically sterilized female patients identified as non-pregnant and non-lactating and consented to contraception both during the trial and within 6 months after the last administration of the test drug Exclusion Criteria: * Metastatic BC, bilateral BC, occult BC, inflammatory BC, or with other malignant tumors * Known history of hypersensitivity to the study drugs * Patients who …