Efficacy and safety of pyrotinib combined with trastuzumab and chemotherapy in patients with HER2-positive locally advanced breast cancer: a multicenter real-world study

OBJECTIVES: This multicenter real-world investigation aimed to assess the outcomes resulting from the incorporation of pyrotinib into trastuzumab and chemotherapy regimens for the neoadjuvant treatment of individuals diagnosed with HER2-positive locally advanced breast cancer (LABC). METHODS: A multicenter retrospective cohort analysis was carried out, including patients diagnosed with HER2-positive locally advanced breast cancer from nine medical institutions in Hebei Province, China. Participants were enrolled from January 2023 to June 2023 and followed until December 2025. Based on the neoadjuvant therapy received, patients were divided into two groups: trastuzumab plus chemotherapy (n=127) and pyrotinib plus trastuzumab and chemotherapy (n=101). The main assessment criterion focused on the rate of total pathological complete response (tpCR). Among the secondary evaluation metrics were the breast pathological complete response (bpCR) rate, the objective response rate (ORR), progression-free survival (PFS), overall survival (OS), as well as adverse events related to the treatment. RESULTS: