Prospective Cohort Study on Oral Microbiome Changes in Patients With Locally Advanced Oral Squamous Cell Carcinoma Following Neoadjuvant Chemoimmunotherapy

This study is tracking changes in the mouth's bacterial environment (oral microbiome) in patients with locally advanced oral cavity cancer who are undergoing induction chemotherapy before surgery. Understanding how the microbiome shifts during treatment may reveal new ways to improve outcomes or manage side effects. **You may be eligible if...** - You are between 18 and 80 years old (any gender) - You have been diagnosed with locally advanced oral squamous cell carcinoma - You have not previously received radiation or chemotherapy for head and neck cancer - Your blood counts, liver, and kidney function meet required levels - Your general health allows you to tolerate chemotherapy **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have epilepsy or an uncontrolled psychiatric disorder - You have severe allergies or an immune deficiency - Your cancer has already spread to distant organs (metastatic) Talk to your doctor to see if this trial is right for you.