title: Primary tumour size is a prognostic parameter in patients suffering from differentiated thyroid carcinoma with extrathyroidal growth: results of the MSDS trial.
abstract: OBJECTIVE
  The Multicentre Study Differentiated Thyroid Cancer (MSDS) collective represents a well-defined group of patients with thyroid carcinomas with extrathyroidal extension. The aim of the present study was to evaluate the relationship of the primary tumour size with clinicopathological features as well as the outcome of patients with minimum and extensive extrathyroidal growth (pT3b- and pT4a-tumours; UICC 2002/2003, 6th ed).
  
  
  METHODS
  The tumour diameter was available in 324 out of 351 MSDS patients (244 females, 80 males). Mean age of patients was 47.7±12.0 years (range, 20.1-69.8 years), and the median follow-up was 6.2 years. The relationship between primary tumour size and the following clinicopathological data was investigated: age, gender, histological tumour type (papillary thyroid carcinomas (PTC) versus follicular thyroid carcinomas (FTC)) and UICC/AJCC TNM classification. In addition, the correlation between primary tumour size and event-free and overall survival was assessed.
  
  
  RESULTS
  The FTC of our series were significantly larger than PTC (3.46 vs 1.84 cm; P<0.001). Patients suffering from pT3b-tumours presented with significantly smaller tumour size than those with extensive extrathyroidal growth (pT4a-tumours) (1.9 vs 3.0 cm; P<0.01). All patients with distant metastases suffered from tumours >2 cm. Furthermore, event-free and overall survival were significantly correlated with increasing tumour size (P<0.05). Using multivariate analysis, a pT4a-category and a tumour diameter >2 cm remained independent predictors of survival.
  
  
  CONCLUSIONS
  In patients suffering from differentiated thyroid carcinoma with extrathyroidal growth (pT3b and pT4a), the tumour size is an independent predictor of event-free and overall survival.
authors.affiliation: Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Strasse 33, Münster, Germany. jan.kraemer@uni-muenster.de
authors.forename: Jan Alexander
authors.initials: JA
authors.lastname: Krämer
authors.forename: Kurt Werner
authors.initials: KW
authors.lastname: Schmid
authors.forename: Henning
authors.initials: H
authors.lastname: Dralle
authors.forename: Markus
authors.initials: M
authors.lastname: Dietlein
authors.forename: Harald
authors.initials: H
authors.lastname: Schicha
authors.forename: Hartmut
authors.initials: H
authors.lastname: Lerch
authors.forename: Joachim
authors.initials: J
authors.lastname: Gerss
authors.forename: Thomas
authors.initials: T
authors.lastname: Frankewitsch
authors.forename: Otmar
authors.initials: O
authors.lastname: Schober
authors.forename: Burkhard
authors.initials: B
authors.lastname: Riemann
mesh_terms: D000328:Adult; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*; D055815:Young Adult