Study of High-Intensity Focused Ultrasound (HIFU) Combined With Toripalimab Plus Chemotherapy Versus Chemotherapy as Neoadjuvant Therapy for Estrogen Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative (ER+/HER2-) Breast Cancer (NeoHunter)

Inclusion Criteria: 1. Female patients aged 18-75 years. 2. Invasive breast cancer without distant metastasis, including either T1c-T2 (≥ 2 cm), cN1-cN2, or T3-T4, cN0-cN2. 3. Histopathologically confirmed ER-positive/HER2-negative, PR \< 20% or Ki67 ≥ 20%, Grade 3 breast cancer. 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. Exclusion Criteria: 1. Female patients during pregnancy or lactation. 2. Diagnosis of bilateral breast cancer, occult breast cancer, or distant metastasis confirmed by pathology. 3. Has an active autoimmune disease that has received systemic treatment in the last 2 years. 4. Has a known history of human immunodeficiency virus (HIV), hepatitis B, or known active hepatitis C virus infection. 5. Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent. 6. Has a known history of invasive malignancy that required systemic treatment in the last 5 years. 7. Uncontrolled concomitant diseases include severe infection, liver disease, cardiovascular disease, kidney disease, respiratory disease, diabetes, and others requiring systemic treatment.