title: Gene-expression Classifier in Papillary Thyroid Carcinoma: Validation and Application of a Classifier for Prognostication.
abstract: BACKGROUND
  No reliable biomarker for metastatic potential in the risk stratification of papillary thyroid carcinoma exists. We aimed to develop a gene-expression classifier for metastatic potential.
  
  
  METHODS
  Genome-wide expression analyses were used. Development cohort: freshly frozen tissue from 38 patients was collected between the years 1986 and 2009. Validation cohort: formalin-fixed paraffin-embedded tissues were collected from 183 consecutively treated patients.
  
  
  RESULTS
  A 17-gene classifier was identified based on the expression values in patients with and without metastasis in the development cohort. The 17-gene classifier for regional/distant metastasis identified was tested against the clinical status in the validation cohort. Sensitivity for detection of metastases was 51.5% and specificity 61.6%. Log-rank testing failed to identify any significance (p=0.32) regarding the classifier's usefulness as a prognostic marker for recurrence.
  
  
  CONCLUSIONS
  A 17-gene classifier for metastatic potential was developed, and the results showed a clear biological difference between groups. However, through validation, no prognostic significance of this classifier was shown.
authors: Department of ENT Head and Neck Surgery, Odense University Hospital, Odense, Denmark Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark stefano.londero@rsyd.dk.
authors: Stefano Christian
authors: SC
authors: Londero
authors: Department of Histopathology, Aarhus University Hospital, Odense, Denmark.
authors: Marie Louise
authors: ML
authors: Jespersen
authors: Department of Pathology, Odense University Hospital, Odense, Denmark.
authors: Annelise
authors: A
authors: Krogdahl
authors: Department of Oncology, Odense University Hospital, Odense, Denmark.
authors: Lars
authors: L
authors: Bastholt
authors: Department of Experimental Clinical Oncology, Aarhus University Hospital, Odense, Denmark.
authors: Jens
authors: J
authors: Overgaard
authors: Department of ENT Head and Neck Surgery, Aarhus University Hospital, Odense, Denmark.
authors: Sten
authors: S
authors: Schytte
authors: Department of ENT Head and Neck Surgery, Odense University Hospital, Odense, Denmark.
authors: Christian
authors: C
authors: Godballe
authors: Department of Experimental Clinical Oncology, Aarhus University Hospital, Odense, Denmark.
authors: Jan
authors: J
authors: Alsner
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics*; D002277:Carcinoma / Q000145:classification / Q000235:genetics* / Q000401:mortality / Q000556:secondary / Q000601:surgery; D002291:Carcinoma, Papillary; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D055106:Genome-Wide Association Study; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000145:classification / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: 749; Thyroid cancer; gene expression; metastasis; papillary thyroid carcinoma; prognostic indicators