Neoadjuvant Chemotherapy in Combination With Toripalimab for HR+/HER2- Breast Cancer (NEOTORCH-BREAST01)

1. Breast cancer is the most common malignant tumor among women worldwide, with 2.3 million women suffering from it every year. In China, the incidence rate of breast cancer is increasing year by year, with about 400000 new cases every year, which seriously threatens the life and health of women in China. Study population: participants with HR+/HER2- breast cancer confirmed by postoperative pathology according to American Joint Committee on Cancer (AJCC) / Union for International Cancer Control (UICC) 8th Tumor Node Metastasis (TNM) staging classification. 2. Sample size: single arm design was used in this study and 30 participants were estimated to be enrolled. 3. Histologically confirmed invasive breast cancer with tumor diameter\>1cm (T1c-3; N0-3; M0). All patients were pathohistologically confirmed as HR+/HER2- breast cancer. According to the breast cancer diagnosis and treatment guidelines and specifications of the Chinese Society of Clinical Oncology, Luminal B is divided into Luminal B (HER2 negative) and Luminal B (HER2 positive). Luminal B (HER2 negative) is ER/PR positive, HER2 negative and Ki-67 proliferation index is high or PR low expression. Luminal type B (HER2 positive) is ER/PR positive, HER2 positive (protein overexpression or gene amplification), and Ki-67 in any state. Therefore, HR+/HER2- breast cancer is a Luminal type breast cancer patient excluding HER2+. 4. Chemotherapy Phase 1: Epirubicin (or Liposomal Doxorubicin)+Cyclophosphamide, intravenous infusion of 100 mg/m2. Epirubicin (or 35 mg/m2 liposomal doxorubicin)+600 mg/m2 cyclophosphamide, starting from the first day of the week, for a total of 12 weeks. Chemotherapy Phase 2: Paclitaxel, administered intravenously at a dose of 260 mg/m2 every 3 weeks for a total of 12 weeks. During neoadjuvant chemotherapy and postoperative adjuvant therapy, use of Toripalimab: intravenous infusion of 240 mg, once every 3 weeks, combined with preoperative and postoperative adjuvant therapy for a total of 1 year. 5. Adverse events (AEs) management: To minimize the risk of AEs, the investigators will monitor carefully to determine whether or not they are within the expected range. Investigators will also conduct a thorough examination and adopt an appropriate system to take any necessary measures to deal with AEs.