Definition: Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
Input: nasopharynx cancer or nasopharyngeal carcinoma (npc) is the most common cancer which is formed in the nasopharynx, most commonly in the postero-lateral nasopharynx or pharyngeal recess or 'fossa of rosenmuller' accounting for 50% cases.
Output:
nasopharynx cancer