title: Increasing thyroid cancer rate and the extent of thyroid surgery in Korea.
abstract: BACKGROUND
  It is evident that the rate of thyroid cancer is increasing throughout the world. One reason is increased detection of preclinical small cancers. However, it is not clear whether the increase in thyroid cancer rate is reducing the extent of thyroid surgeries. The purpose of this study was to evaluate the thyroid cancer rate and analyze recent changes in the extent of thyroid cancer surgeries in Korea.
  
  
  METHODS
  An observational study was conducted using data from Korea's Health Insurance Review and Assessment Service (HIRAS) for thyroidectomy with/without neck dissection, with 228,051 registered patients between 2007 and 2011. Data were categorized by the extent of surgery: unilateral thyroidectomy without neck dissection (UT), bilateral thyroidectomy or radical thyroidectomy without neck dissection (TT), any thyroidectomy with unilateral selective neck dissection (SND), any thyroidectomy with unilateral modified radical neck dissection (MRND), any thyroidectomy with unilateral radical neck dissection (RND), and any thyroidectomy with bilateral neck dissection (BND). Annual rate difference for each surgery was analyzed with a linear by linear association.
  
  
  RESULTS
  The absolute numbers of total thyroid surgeries (UT+TT+SND+MRND+RND+BND) were increased from 28539 to 61481. The proportion of patients who underwent only thyroidectomy without neck dissection (UT+TT) decreased from 67.30% to 60.50%, whereas the proportion of patients who underwent neck dissection (SND+MRND+RND+BND) increased from 32.70% to 39.50% during the 5-year study period.
  
  
  CONCLUSIONS
  Despite the increase in rate of thyroid cancer due to earlier detection, increased rate of neck dissection was noted.
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Myung-Whun
authors.initials: MW
authors.lastname: Sung
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: Bumjung
authors.initials: B
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Thyroid/Head & Neck Cancer Center of the Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, Korea.
authors.forename: Soo-Youn
authors.initials: SY
authors.lastname: An
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: J Hun
authors.initials: JH
authors.lastname: Hah
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Seoul National University Boramae Hospital, Seoul, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Hallym University Sacred Heart Hospital, Anyang, Korea.
authors.forename: Hyo Geun
authors.initials: HG
authors.lastname: Choi
mesh_terms: D000328:Adult; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection / Q000379:methods / Q000639:trends; D056910:Republic of Korea; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods / Q000639:trends