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

Circulating tumor DNA (ctDNA) is a blood-based test that measures dying or dead cancer cells that are already circulating in the blood. In this study, the investigators will enroll patients who are planning to receive surgery to remove their head and neck cancer. The investigators are interested to learn how ctDNA levels change with surgery and over the course of time. The investigators also want to determine if there are certain features of the tumor or the patient themselves that might cause ctDNA to be higher than other patients. Also, the investigators want to explore if the detection of ctDNA following surgery is related to cancer recurrence.