title: Familial non-medullary thyroid cancer: a matched-case control study.
abstract: OBJECTIVE
  Familial non-medullary thyroid cancer (FNMTC) is a newly recognized disease entity and can be distinguished from the more common sporadic non-medullary thyroid cancer. The purpose of this study was to determine some of the potential distinguishing features of FNMTC.
  
  
  METHODS
  Retrospective association study and matched-case control study.
  
  
  METHODS
  Five hundred forty-three cases of well-differentiated follicular origin thyroid cancers were identified and collected in a database. Among this population, 24 cases of FNMTC were identified. A case of FNMTC was defined as a patient with the following two criteria: a well-differentiated follicular origin thyroid cancer and at least one first-degree relative with a well-differentiated epithelial origin thyroid cancer. The unmatched sporadic and FNMTC groups were compared using t test, Phi test, Cramer V test, and Pearson and Spearman correlation tests. Twenty-four FNMTC cases were matched to 24 sporadic cases based on age, gender, stage of disease at presentation, and tumor size. Clinicopathologic features, management, and outcome were analyzed statistically using a matched-proportional z test. Disease-free survival and disease-specific survival were analyzed using log-rank test and the Kaplan-Meier function. A P-value less than .05 was considered statistically significant.
  
  
  RESULTS
  : There was no significant difference in ionizing radiation exposure, disease multifocality, surgical management, or recurrence between the sporadic and FNMTC patients. Although FNMTC patients tend to have improved disease-free survival and disease-specific survival, the difference was not significant at the 5% level.
  
  
  CONCLUSIONS
  Although FNMTC is characterized by strong family history, these patients do not tend to have worse prognosis.
authors.affiliation: Mount Sinai Hospital, 600 University Avenue-401, Toronto, Ontario M5G 1X5, Canada. j.freeman@utoronto.ca
authors.forename: Evelyn Linda
authors.initials: EL
authors.lastname: Maxwell
authors.forename: Francis T
authors.initials: FT
authors.lastname: Hall
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Freeman
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009864:Ontario / Q000453:epidemiology; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods; D016896:Treatment Outcome