Toripalimab With Chemotherapy for Sinus Cancer

This study is testing whether adding toripalimab (an immunotherapy drug) to standard chemotherapy before surgery can improve outcomes for patients with locally advanced cancer of the nasal cavity or paranasal sinuses (the air-filled spaces around the nose). The goal is to shrink the tumor before surgery, making it easier to remove completely. **You may be eligible if...** - You are 18 or older - You have confirmed locally advanced squamous cell carcinoma or sinonasal undifferentiated carcinoma (SNUC) of the nasal cavity or sinus - Your cancer is in stage III or IVA/IVB based on tumor size and lymph node involvement - Your cancer is potentially resectable (removable by surgery) or borderline resectable - You are in good general health with adequate organ function (ECOG 0–1) **You may NOT be eligible if...** - You have a different type of sinus cancer not listed in the study criteria - You have active autoimmune disease requiring treatment - You have had prior immunotherapy or significant immune-suppressing conditions - You have significant organ dysfunction that would make chemotherapy or surgery unsafe Talk to your doctor to see if this trial is right for you.