Pyrotinib Maleate, Trastuzumab, SHR6390 and Letrozole in Combination for Stage II-III TPBC

After providing written informed consent, the participants will undergo combined treatment of pyrotinib maleate, CDK4/6 inhibitor dalpiciclib, trastuzumab and letrozole. The effectiveness of the combined treatment will be evaluated by MRI every two treatment cycles. If the disease progresses, the participant will withdraw from the trial. If the combined treatment has identified effectiveness, the participant will undergo surgical treatment within 4 weeks (over 2 weeks) after termination of the neoadjuvant treatment. The patients will be followed up for 5 years.