title: Influence of age and primary tumor size on the risk for residual/recurrent well-differentiated thyroid carcinoma.
abstract: BACKGROUND
  Though age and primary tumor size predict cancer-specific survival in well-differentiated thyroid carcinoma (WDTC), their influence on residual/recurrent disease has not been elucidated.
  
  
  METHODS
  In a retrospective study, residual/recurrent disease was defined by the surrogate outcome of positive (>or=2 microg/L) follow-up stimulated thyroglobulin after surgery and radioactive remnant ablation. Age, primary tumor size, and clinical staging systems were examined in the context of stimulated thyroglobulin outcome.
  
  
  RESULTS
  A total of 246 patients were followed up for a mean of 5.8 years. No significant difference in age (t(239) = 0.61, p > .05) or tumor size (t(237) = 0.16, p > .05) was found among patients with positive follow-up stimulated thyroglobulin compared with those with negative results. pTNM staging failed to demonstrate significant, stage-dependent increase in the percentage of patients with positive stimulated thyroglobulin, chi(2)(2, N = 229) = 0.17, p > .05, unlike staging based solely on surgical pathology, chi(2)(2, N = 241) = 34.97, p < .001.
  
  
  CONCLUSIONS
  Age, primary tumor size, and pTNM staging do not predict risk for residual/recurrent WDTC, whereas extrathyroidal extension at initial surgery is predictive.
authors.affiliation: Medicine/Endocrine Division, Mount Sinai Hospital, University of Toronto Medical School, Toronto, Ontario, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Orlov
authors.forename: David
authors.initials: D
authors.lastname: Orlov
authors.forename: Michael
authors.initials: M
authors.lastname: Shaytzag
authors.forename: Mark
authors.initials: M
authors.lastname: Dowar
authors.forename: Vafa
authors.initials: V
authors.lastname: Tabatabaie
authors.forename: Philip
authors.initials: P
authors.lastname: Dwek
authors.forename: Jonathan
authors.initials: J
authors.lastname: Yip
authors.forename: Cindy
authors.initials: C
authors.lastname: Hu
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Freeman
authors.forename: Paul G
authors.initials: PG
authors.lastname: Walfish
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000401:mortality / Q000473:pathology; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013954:Thyroglobulin / Q000008:administration & dosage / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D013954:Thyroglobulin