title: The stratification of patient risk depending on the size and ratio of metastatic lymph nodes in papillary thyroid carcinoma.
abstract: BACKGROUND
  The aims of this study were to identify the clinical significances of the size of metastatic lymph node (mLN) and LN ratio (LNR) and to attempt to create a risk stratification for papillary thyroid carcinoma (PTC) patients.
  
  
  METHODS
  We investigated the 435 PTC patients who underwent radioactive iodine (RAI) ablation treatment following thyroid surgery. The patients were classified into two groups (micrometastasis (pN1mic) ≤ 0.2 cm and macrometastasis (pN1mac) > 0.2 cm) and were stratified into the following three risk groups: group I (pN1mic, LNR ≤ 0.5); group II (pN1mic, LNR > 0.5 or pN1mac, LNR ≤ 0.5); and group III (pN1mac with LNR > 0.5). And then we investigated the association of the classified groups and variable clinicopathologic factors.
  
  
  RESULTS
  The clinical characteristics such as large tumor size, extrathyroidal extension, higher T stage, and greater number of mLN or LNR were significantly associated with pN1mac. The mean stimulated thyroglobulin levels were increased with the patient risk groups (p = 0.02). The recurrence-free survivals were significantly different between the stratified groups (p = 0.001).
  
  
  CONCLUSIONS
  The patient groups I, II, and III may be referred to as low-, intermediate-, and high-risk groups. Clinicians should consider the possibility of recurrence, and the decisions about the application of RAI ablation based on the size of mLN and the patient's risk groups.
authors.affiliation: Department of Surgery, CHA Bundang Medical Center, CHA University, Gyeonggi-do, Korea.
authors.forename: Young Ran
authors.initials: YR
authors.lastname: Hong
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: So Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Dong Jun
authors.initials: DJ
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Hospital Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Chan Kwon
authors.initials: CK
authors.lastname: Jung
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Byung Joo
authors.initials: BJ
authors.lastname: Chae
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Byung Joo
authors.initials: BJ
authors.lastname: Song
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. drbae@catholic.ac.kr.
authors.forename: Ja Seong
authors.initials: JS
authors.lastname: Bae
mesh_terms: D002291:Carcinoma, Papillary / Q000556:secondary* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy
keywords: Lymph node size; Papillary thyroid carcinoma; Prognosis; Ratio of lymph node; Risk stratification