title: Practical Performance of the 2015 American Thyroid Association Guidelines for Predicting Tumor Recurrence in Patients with Papillary Thyroid Cancer in South Korea.
abstract: The 2015 American Thyroid Association (ATA) management guidelines for adult patients with differentiated thyroid cancer propose the use of the modified initial risk stratification and response to therapy re-stratification systems. This study was conducted to validate the practicality of the revised guidelines for predicting tumor recurrence in patients with differentiated thyroid cancer.
  
  
  
  Patients with papillary thyroid cancer (n = 2425) who underwent total thyroidectomy with central neck node dissection with or without modified radical neck node dissection at a single institution between October 1985 and July 2009 were retrospectively enrolled. The accuracy of three different risk-stratification strategies for predicting disease-free survival, set out in the 2009 and 2015 ATA management guidelines, was assessed: the initial risk stratification (ATA 2009-RSS), the modified initial risk stratification (ATA 2015-RSS), and the response to therapy re-stratification (ATA 2015-RTR).
  
  
  
  After applying the ATA 2015-RSS, 258/1913 (13.5%) of patients originally designated as intermediate risk by the ATA 2009-RSS were designated as low risk. This was mainly due to the small number of metastatic lymph nodes. Recurrence was detected in 136 (5.6%) patients during follow-up. Of the 2425 cases examined, 375 were designated as low risk by the ATA 2009-RSS, with a recurrence rate of 1.1%. However, the ATA 2015-RSS designated 633 (26.1%) cases as low risk, with a recurrence rate of 0.9%. Implementing the ATA 2015-RTR predicted an excellent response in 1597 (65.9%) cases, with a recurrence rate of 1.1%. According to the proportion of variance explained (PVE), the Akaike information criterion, Harrell's c index, and integrated area under the curve, comparing the predictive accuracy of the ATA 2009-RSS, ATA 2015-RSS, and ATA 2015-RTR revealed that the ATA 2015-RTR was a superior predictor of recurrence.
  
  
  
  A proportion of patients designated as intermediate risk by the ATA 2009-RSS were designated as low risk by the ATA 2015-RSS. The ATA 2015-RTR may be the most accurate predictor of risk of recurrence.
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Seul Gi
authors.initials: SG
authors.lastname: Lee
authors.affiliation: 2 Department of Internal Medicine, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Lee
authors.affiliation: 3 Biostatistics Collaboration Unit, Yonsei University College of Medicine , Seoul, Korea.
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Lee
authors.affiliation: 3 Biostatistics Collaboration Unit, Yonsei University College of Medicine , Seoul, Korea.
authors.forename: Jieun
authors.initials: J
authors.lastname: Moon
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Cho Rok
authors.initials: CR
authors.lastname: Lee
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Sang Wook
authors.initials: SW
authors.lastname: Kang
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Jong Ju
authors.initials: JJ
authors.lastname: Jeong
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Kee-Hyun
authors.initials: KH
authors.lastname: Nam
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Woong Youn
authors.initials: WY
authors.lastname: Chung
authors.affiliation: 2 Department of Internal Medicine, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Young Suk
authors.initials: YS
authors.lastname: Jo
authors.affiliation: 1 Department of Surgery, Open NBI Convergence Technology Research Laboratory, Severance Hospital, Yonsei Cancer Center , Seoul, Korea.
authors.forename: Jandee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000453:epidemiology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D011379:Prognosis; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology*; D013965:Thyroidectomy
keywords: papillary thyroid cancer; practice guidelines; predictive accuracy; recurrence; risk stratification