Patients undergo standard curative resection and neck node dissection (if appropriate). Specimens are collected from tumor tissue (necrosis-free, if possible), each wound quadrant, any neck disease with clinically negative nodes, and any neck disease with a single positive node for histologic and molecular analysis. Tissue and cells are examined for p53 mutation and DNA microsatellite repeat alterations. Patients undergo adjuvant radiotherapy and/or chemotherapy, as appropriate for clinical staging and histopathology, at the discretion of the participating clinician.