Circulating Tumor DNA (ctDNA) in Locally Advanced Head and Neck Squamous Cell Carcinoma

This study is measuring circulating tumor DNA (ctDNA) — tiny fragments of cancer DNA found in the blood — in patients with head and neck squamous cell carcinoma who are undergoing surgery. The goal is to understand whether blood-based tests can detect remaining cancer after surgery and predict who needs additional treatment. **You may be eligible if...** - You are 18 or older - You have a newly diagnosed squamous cell carcinoma of the mouth, throat, or voice box, confirmed by biopsy - You are planning to undergo surgery to remove the tumor at UNC-CH hospital with the goal of cure - Your cancer is at a locally advanced stage (T3–T4, or any stage with lymph node involvement, but no distant spread) - You are willing to receive additional therapy (radiation and/or chemotherapy) after surgery if needed **You may NOT be eligible if...** - The cancer has spread to other parts of your body - You are pregnant or breastfeeding - You have had another cancer in the past 5 years - You have already received chemotherapy or radiation for this cancer Talk to your doctor to see if this trial is right for you.