The study evaluate the pathological complete response rate, event-free survival, disease-free survival, overall survival and safety of pyrotinib in combination with trastuzumab, pertuzumab and nab-paclitaxel as neoadjuvant therapy in early stage or locally advanced HER2-positive breast cancer. Patients will receive 4 cycles of pyrotinib in combination with trastuzumab, pertuzumab and nab-paclitaxel or 4 cycles of trastuzumab, pertuzumab and nab-paclitaxel as neoadjuvant therapy, then undergo surgery, then receive adjuvant chemotherapy and targeted therapy according to pathologic response and physician's choice.

