title: Histology does not influence prognosis in differentiated thyroid carcinoma when accounting for age, tumour diameter, invasive growth and metastases.
abstract: OBJECTIVE
  Papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) show considerable differences in disease stage at initial presentation. The aim of this study was to investigate whether there are differences in tumour-specific survival if initial staging is accounted for.
  
  
  METHODS
  Retrospective chart review study.
  
  
  METHODS
  The study sample comprised 875 PTC and 350 FTC patients (856 females, 369 males, mean age 47.8 years) treated in our hospital from 1978 to 2002. All patients received total thyroidectomy with subsequent I-131 ablation except for those patients with an isolated papillary microcarcinoma.
  
  
  METHODS
  Kaplan-Meier analyses and Cox-regression analyses were performed to assess the influence of histology on thyroid cancer-specific survival.
  
  
  RESULTS
  FTC patients were on average older, more likely to be male, presented with a larger tumour and more frequently had multifocal carcinoma and distant metastases than PTC patients, whereas they presented less frequently with extrathyroidal invasion or lymph node metastases. Twenty-year tumour-specific survival in PTC was 90.6% and in FTC 73.7% (P<0.001). In multivariate analysis the presence of distant metastases (P<0.001), age (P<0.001), tumour size (P=0.001) and the presence of extrathyroidal invasion (P=0.007), but not histology (P=0.26), were independent determinant variables for tumour-specific survival.
  
  
  CONCLUSIONS
  There is no difference in tumour-specific survival between PTC and FTC when accounting for the presence of metastases, age, tumour size and the presence of extrathyroidal invasion.
authors.affiliation: Department of Nuclear Medicine, Würzburg University, Würzburg, Germany. verburg_e@klinik.uni-wuerzburg.de
authors.forename: Frederik A
authors.initials: FA
authors.lastname: Verburg
authors.forename: Uwe
authors.initials: U
authors.lastname: Mäder
authors.forename: Markus
authors.initials: M
authors.lastname: Luster
authors.forename: Christoph
authors.initials: C
authors.lastname: Reiners
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002291:Carcinoma, Papillary / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018265:Carcinoma, Papillary, Follicular / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D002648:Child; D016208:Databases, Factual; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D055815:Young Adult