Oropharyngeal cancer occurs in the tissue of the oropharynx, the middle part of the throat that includes the base of the tongue, the tonsils, the soft palate and the walls of the pharynx, which is the cavity behind the nose and the mouth. Many types of tumors can grow in the oral cavity and oropharynx, including benign (non cancerous) growths that don’t spread, harmless growths that can later become cancerous, and cancerous tumors that grow into the adjacent tissue and spread to other parts of the body.