title: Sex is not an independent risk factor for survival in differentiated thyroid cancer.
abstract: OBJECTIVE
  To determine the impact of sex on disease-specific survival (DSS) in differentiated thyroid cancer.
  
  
  METHODS
  Retrospective analysis of population database.
  
  
  METHODS
  Adult patients with papillary thyroid carcinoma (PTC) or follicular thyroid carcinoma (FTC) were identified from the Surveillance, Epidemiology, and End Results Database between 1988 and 2003. Patients were grouped according to tumor type (PTC or FTC), with age, sex, tumor size, extension, and nodal or distant metastases recorded. The Kaplan-Meier method was used to compare DSS based on sex in each group.
  
  
  RESULTS
  We identified 36,725 patients, of which 77% were female and 23% were male. PTC represented 91.3% of patients and FTC the remaining 8.7%. Males with PTC and FTC were diagnosed at an older age and were significantly more likely to present with advanced-stage disease. In patients ≥45 years old, DSS was similar in male and female patients; however, in patients <45 years old, DSS was significantly worse in males. When compared by stage, DSS was similar among male and female patients with stage II PTC; however, males with stage I PTC had a minimally reduced DSS. Stage-stratified analysis revealed no DSS difference between male and female patients with FTC.
  
  
  CONCLUSIONS
  Male sex does not portray an independent survival risk in differentiated thyroid cancer when survival is compared by disease stage. Men present at a later age with more advanced disease, which may explain their poorer survival seen in some studies.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, U.S.A.
authors.forename: Sam L
authors.initials: SL
authors.lastname: Oyer
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Smith
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Lentsch
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000453:epidemiology*; D000328:Adult; D002277:Carcinoma / Q000453:epidemiology*; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000453:epidemiology*
keywords: Differentiated thyroid cancer; Epidemiology; Surveillance; and End Results database; sex; survival