For the hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) subtype of breast cancer, although surgical, radiotherapy, and endocrine treatments have shown better survival, this subtype has a relatively poor response to neoadjuvant chemotherapy and immunotherapy, with an approximately pCR of 20%. The low immunogenicity result in suboptimal pCR and objective response rates for this group. Therefore, there is an urgent need to explore new, highly effective, and low-toxicity treatment strategies to further improve the efficacy of HR+/HER2- breast cancer. Radiotherapy has systemic immune regulatory effects by promoting the release of antigens from tumor cells, enhancing T-cell infiltration, and directly killing tumor cells. Therefore, this study aims to investigate the efficacy and safety of chemotherapy combined with PD-1 inhibitor and different radiotherapy fractionations in the neoadjuvant treatment of HR+/HER2- breast cancer.
1. Histologically or cytologically confirmed HR+/HER2- breast cancer
2. cT1c-2N1-2M0 or cT3N0-2M0（AJCC 7th）
3. ECOG performance status of 0-1;
4. Adequate bone marrow function, defined as: Hb ≥ 9.0 g/dL (90 g/L); ANC ≥ 1,500/mcL (1.5 × 10^9/L); PLT ≥ 100,000/mcL (100 × 10^9/L) and no blood transfusion within 3 weeks or growth factor (G-CSF, EPO) therapy within 2 weeks prior to dosing;
1. Patients with a history of mental illness or those diagnosed with mental disorders at the time of enrollment in the clinical trial.
2. Patients with communication barriers due to confusion, aphasia, intellectual disability, or other reasons that prevent them from responding normally.
3. Poorly controlled tumor-related pain.
4. Patients participating in other clinical studies simultaneously.
Lei Liu
Lead sponsor
West China Hospital
Sponsor institution