Neoadjuvant Chemotherapy Combined With Preoperative Radiotherapy for Locally Advanced Breast Cancer

Approximately one fifth of the patients in China have non-metastatic locally advanced breast cancer. Due to their relatively low overall survival rate, high recurrence rate, and risk of distant metastasis, this significantly affects the therapeutic efficacy and survival of the patients. Preoperative neoadjuvant radiotherapy is a common treatment option for many tumors (such as esophageal cancer, rectal cancer, soft tissue sarcoma, etc.), by advancing radiotherapy and systemic chemotherapy to before surgery to enhance preoperative treatment for tumor downstaging and early elimination of micrometastatic lesions to improve overall survival rate. In breast cancer patients, preoperative radiotherapy combined with chemotherapy has the opportunity to further shrink the tumor, increase the probability of breast preservation, and possibly avoid axillary lymph node dissection, thereby improving the quality of life of the patients. Pathological complete response (pCR) not only helps subsequent surgical treatment but also has significant advantages in improving survival rate, significantly improving the overall prognosis of patients. Neoadjuvant radiotherapy is also one of the treatment options for reducing the stage. However, this combination has not been widely applied to breast cancer patients yet and further clinical research is needed. Among all breast cancers, Luminal-type breast cancer accounts for 50-70%, among which patients with HR+HER2- type breast cancer have poor efficacy of neoadjuvant chemotherapy and the pCR rate is usually below 5-10%. Triple-negative breast cancer accounts for 15-20% of all breast cancer subtypes, characterized by poor differentiation, strong invasiveness, earlier and more frequent recurrence and metastasis. The efficacy of traditional neoadjuvant chemotherapy has approached its limit and the pCR rate hovers around 35%. This study aims to explore the pCR rate, effectiveness and safety of preoperative chemotherapy combined with preoperative medium-dose fractionated radiotherapy in patients with locally advanced HR+HER2- type and triple-negative breast cancer, to improve the overall survival of these patients.