title: Risk stratification of patients with locally aggressive differentiated thyroid cancer. Results of the MSDS trial.
abstract: The Multicentre Study Differentiated Thyroid Cancer (MSDS) collective represents a well defined group of patients with locally aggressive thyroid carcinomas (pT4; AJCC/UICC 1997). The aim of the present study was to compare the survival of patients with minimum and extensive extrathyroidal growth according to the new AJCC/UICC TNM staging system 2009.
  
  
  METHODS
  The follow-up data of 347 patients were analysed. Patients were reclassified according to the current AJCC/UICC 2009 classification. The event-free and overall survival was evaluated using Kaplan-Meier analysis. In addition, postoperative complications and status of disease were documented.
  
  
  RESULTS
  327 patients were assigned to stage pT3 and 20 patients to stage pT4a, respectively. Median follow-up was 6.1 years (range 0.04-9.8 years). 92.5% of patients reached complete remission. There were 7.8 % recurrences in the thyroid bed, in locoregional lymph nodes and/or in distant sites. The overall survival was >98% both in pT3 and pT4a patients (p = n. s.). In contrast, the event-free survival was significantly less favourable in pT4a patients (p < 0.001). Using multivariate analysis the following parameters were significant predictors of event-free survival: histological tumour type, degree of extrathyroidal extension and nodal metastasis (p < 0.05).
  
  
  CONCLUSIONS
  The MSDS patients with locally aggressive differentiated thyroid cancer showed an excellent overall survival during a median follow-up of 6.1 years. According to the current AJCC/UICC 2009 classification, pT3 patients with minimal extrathyroidal extension revealed a significantly better event-free survival than pT4a patients with extensive extrathyroidal growth.
authors.affiliation: Department of Nuclear Medicine, University Hospital, 48149 Muenster, Germany. riemann.burkhard@uni-muenster.de
authors.forename: Burkhard
authors.initials: B
authors.lastname: Riemann
authors.forename: J A
authors.initials: JA
authors.lastname: Krämer
authors.forename: K W
authors.initials: KW
authors.lastname: Schmid
authors.forename: H
authors.initials: H
authors.lastname: Dralle
authors.forename: M
authors.initials: M
authors.lastname: Dietlein
authors.forename: H
authors.initials: H
authors.lastname: Schicha
authors.forename: C
authors.initials: C
authors.lastname: Sauerland
authors.forename: T
authors.initials: T
authors.lastname: Frankewitsch
authors.forename: O
authors.initials: O
authors.lastname: Schober
mesh_terms: D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000473:pathology; D002454:Cell Differentiation; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009367:Neoplasm Staging; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*; D013997:Time Factors