title: Recommendation for subclass evaluation of TNM stage iva papillary thyroid carcinomas: T4aN1b patients are at risk for recurrence and survival.
abstract: BACKGROUND
  Although all tumor, node, metastasis system (TNM) stage IVA papillary thyroid carcinomas (PTCs) do not seem to behave equivalently as a result of various tumor and node stages, to our knowledge, subclass evaluation has never been attempted.
  
  
  METHODS
  We reviewed 119 stage IVA PTC patients who underwent initial thyroidectomy with modified neck dissection as curative surgery at our institution (33 male patients, 86 female patients; age 61.6 years; follow-up 87.7 months). These patients were divided into groups A (T1-3N1b; n = 79), B (T4aN0-1a; n = 9), and C (T4aN1b; n = 31). Outcomes were compared between the groups.
  
  
  RESULTS
  The rates of recurrence (P < .05) and disease mortality (P < .001) were 13.9% and 1.3%, 0% and 0%, and 35.5% and 19.4% in groups A, B, and C, respectively. The 10-year disease-free survival (DFS) and disease-specific survival (DSS) were 73.4% and 97.9%, 100% and 100%, and 54.9% and 69.7% in groups A, B, and C, respectively. DFS and DSS curves differed significantly between group A + B and group C (P < .005 and P < .0005, respectively). The relative risks of DFS and DSS in group C were 2.8-fold and 14.9-fold, respectively, compared with group A (P < .05), and 3.2-fold and 17.5-fold compared with group A + B (P < .01). Thus, outcomes were worse in group C. In multivariate analysis, esophageal invasion and lymphadenopathy were independent risk factors for both DFS and DSS in stage IVA PTC patients.
  
  
  CONCLUSIONS
  Outcomes in stage IVA are not equivalent, and patients with T4aN1b are at greater risk for worse prognosis. Therefore, we recommend subclass evaluation for TNM stage IVA PTCs.
authors.affiliation: Department of General Surgery, Yokohama City University Hospital and Medical Center, 3-9 Fukuura, Kanazawa-ku, Yokohama City, Kanagawa, 236-0004, Japan. Wadan523@aol.com
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Wada
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Masudo
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Nakayama
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Suganuma
authors.forename: Kenichi
authors.initials: K
authors.lastname: Matsuzu
authors.forename: Shohei
authors.initials: S
authors.lastname: Hirakawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Rino
authors.forename: Munetaka
authors.initials: M
authors.lastname: Masuda
authors.forename: Toshio
authors.initials: T
authors.lastname: Imada
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality / Q000556:secondary* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000401:mortality / Q000556:secondary* / Q000628:therapy; D005260:Female; D006287:Health Planning Guidelines; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D013965:Thyroidectomy; D016896:Treatment Outcome