Breast cancer is the most common malignant tumor in Chinese women, with 20% to 30% HER2 overexpression. Pathological complete remission (pCR) after neoadjuvant therapy in HER2-positive early stage breast cancer patients is closely related to disease-free survival (DFS) and overall survival (OS), which makes pCR an important evaluation indicator of recurrence risk. Trastuzumab combined with pertuzumab is a new standard targeted treatment regimen for HER2-positive early breast cancer, with overall pCR rate of 57% to 66%. However, there are still quite a few patients who do not reach PCR after treatment in clinical practice. For patients who do not reach pCR with neoadjuvant therapy, current guidelines recommend the use of TDM-1 for intensive treatment after surgery, but even with TDM-1, a significant number of patients still have recurrence or metastasis. Besides, TDM-1 is currently unavailable in China. Pyrotinib has been approved for HER2-positive breast cancer patients who have previously failed after the treatment of trastuzumab. The investigators intend to conduct this single-arm, single-center phase II clinical study. Patients with poor response to the standard neoadjuvant treatment regimen of trastuzumab combined with pertuzumab are enrolled. These patients receive pyrotinib to observe that whether pCR has been improved after the replacement of targeted treatment regimen. The investigators aim to explore the effect of pyrotinib in patients with poor response to standard dual-target neoadjuvant therapy, and further explore the improvement of neoadjuvant treatment strategy in HER2 positive early stage breast cancer patients.
Pathological complete remission (pCR) after neoadjuvant therapy in HER2-positive early breast cancer patients is closely related to disease-free survival (DFS) and overall survival (OS), which makes pCR an important evaluation indicator of recurrence risk. Trastuzumab combined with pertuzumab is a new standard targeted treatment regimen for HER2-positive early breast cancer. However, there are still quite a few patients who do not reach PCR. For these patients, current guidelines recommend the use of TDM-1 for intensive treatment after surgery, although a significant number of patients still have recurrence or metastasis. Besides, TDM-1 is unavailable in China. Pyrotinib has been approved for HER2-positive breast cancer patients who have previously failed after the treatment of trastuzumab. The investigators intend to conduct this phase II clinical study. Patients with poor response to the standard neoadjuvant treatment regimen of trastuzumab combined with pertuzumab are enrolled. These patients receive pyrotinib to observe that whether pCR has been improved. The investigators aim to explore the effect of pyrotinib in patients with poor response to standard dual-target neoadjuvant therapy, and further explore the improvement of neoadjuvant treatment strategy in HER2 positive early stage breast cancer patients.