[1] Natl Canc Ctr, Res Inst & Hosp, Ctr Thyroid Canc, Mol Epidemiol Branch,Div Canc Epidemiol & Prevent, Goyang 411764, Gyeonggi Do, South Korea
[2] Natl Canc Ctr, Res Inst & Hosp, Ctr Thyroid Canc, Canc Registrat & Stat Branch,Div Canc Registrat &, Goyang 411764, Gyeonggi Do, South Korea
[3] Natl Canc Ctr, Dept Otolaryngol Head & Neck Surg, Head & Neck Oncol Clin, Ctr Thyroid Canc,Res Inst & Hosp, Goyang 411764, Gyeonggi Do, South Korea