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Chronic exposure to tobacco smoke , which contains over 60 tumor - initiating carcinogens , is the major risk factor for development of lung cancer , accounting for a large portion of cancer - related deaths worldwide .
 tumor, lung cancer, cancer
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 tumor, lung cancer, cancer