RecruitingBiological interventionStudy to Identify Biomarkers of Oral Cavity Cancer Response to Neoadjuvant Immunotherapy Prior to Definitive SurgeryThe goal of this clinical trial is to study whether researchers can create a patient-specific tumor system, called a culture vessel, in a timely manner and determine if it can predict how someone will respond to a specific therapy. Participants will: * Undergo a research biopsy * Take pembrolizumab per standard of care prior to surgery