title: A population-based analysis of survival factors in differentiated and medullary thyroid carcinoma.
abstract: OBJECTIVE
  The study purpose was to determine survival and prognostic factors for differentiated thyroid carcinoma (DTC).
  
  
  METHODS
  Cases of DTC were extracted from the Surveillance, Epidemiology and End Results database from 1988 through 1998. Kaplan-Meier survival analysis was conducted for papillary, follicular, and medullary histologies. Cox proportional hazard analysis was used to examine the influence of age, gender, tumor size, local extension, and cervical node involvement on overall survival.
  
  
  RESULTS
  A total of 18,118 cases were identified, including 15,820 (87.3%) papillary carcinomas, 1799 (9.9%) follicular carcinomas, and 499 (2.8%) medullary carcinomas. Mean survival (10-year survival) was 122 (87.7%), 117 (80.2%), and 108 (73.7%) months for papillary, follicular, and medullary tumors, respectively. For each histology, increasing age, male gender, and degree of local extension substantially reduced survival. Cervical metastasis did not influence survival for papillary or follicular carcinomas but approached significance for medullary carcinoma (P = 0.065).
  
  
  CONCLUSIONS
  Degree of local extension in thyroid carcinoma should be subclassified to more accurately determine prognosis. Treatment of the neck should be considered for medullary thyroid carcinoma.
authors.affiliation: Division of Otolaryngology, Brigham and Women's Hospital, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA. neiloy@massmed.org
authors.forename: Neil
authors.initials: N
authors.lastname: Bhattacharyya
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001707:Biopsy, Needle; D018276:Carcinoma, Medullary / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D002291:Carcinoma, Papillary / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D016001:Confidence Intervals; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011159:Population Surveillance; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy