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)

This study is testing whether adding HIFU (a focused ultrasound treatment that uses heat to target tumors) along with an immunotherapy drug (toripalimab) to standard chemotherapy works better than chemotherapy alone before surgery for a certain type of hormone-positive, HER2-negative breast cancer. **You may be eligible if...** - You are a woman between 18 and 75 years old - You have invasive breast cancer that hasn't spread to distant organs - Your tumor is hormone receptor-positive and HER2-negative, with specific features (low progesterone receptor expression or high cell growth rate or grade 3) - Your tumor is larger than 2 cm or you have lymph node involvement - You are in good general health (ECOG 0–1) **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have cancer in both breasts or cancer that has spread to distant organs - You have significant immune system or autoimmune conditions Talk to your doctor to see if this trial is right for you.