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Papillary thyroid carcinoma ( PTC ) frequently metastasizes to the regional lymph nodes and , thus , guidelines edited by Japan Association of Endocrine Surgeons / Japanese Society of Thyroid Surgery routinely recommend central node dissection even for patients with no clinically detectable node metastasis ( N0 ) .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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