- Histologically proven epidermoid/squamous cell carcinoma of the oral cavity, lip, hypopharynx, oropharynx, nasopharynx, sinonasal tract, or larynx; undifferentiated carcinoma of the nasopharynx (WHO type III); sinonasal undifferentiated carcinoma; or squamous cell carcinoma of unknown primary or the skin with initial presentation in the head and neck region