title: Increase in the incidence of differentiated thyroid carcinoma in children, adolescents, and young adults: a population-based study.
abstract: OBJECTIVE
  To investigate trends in incidence of differentiated thyroid carcinomas among children and adolescents and young adults.
  
  
  METHODS
  In this ecological time-trends study, we selected cases of differentiated thyroid carcinomas (1984-2010) in patients <30 years from Surveillance, Epidemiology, and End Results 9 cancer registries by using International Classification of Diseases for Oncology, 3rd edition, codes for papillary and follicular cancers. Patients with multiple other primary diseases before differentiated thyroid carcinomas were excluded. SEER*Stat software, version 8.0.4 (National Cancer Institute, Bethesda, Maryland) was used to calculate age-standardized rates (estimated per 1,000,000/persons) and annual percentage changes (APCs) were calculated by the Joinpoint model (Joinpoint software, version 4.0.4; National Cancer Institute).
  
  
  RESULTS
  Rates ranged from 2.77 (1990) to 9.63 (2009) and from 18.35 (1987) to 50.99 (2009), for male and female subjects, respectively. A significant increasing trend in incidence was observed for both male (APC 3.44; 95% CI 2.60-4.28) and female (APC 3.81; 95% CI 3.38-4.24) patients. When a stratified analysis on the basis of tumor size was performed, significant increasing trends were noted for the following categories: <0.5 cm (females: APC 5.09, 95% CI 3.54-6.65), 0.5-0.9 cm (females: APC 8.45, 95% CI 7.09-9.82), 1.0-1.9 cm (males: APC 5.09, 95% CI 3.20-7.01; females: APC 3.42, 95% CI 2.78-4.07), and ≥2 cm (males: APC 2.62, 95% CI 1.64-3.60; females: APC 2.96, 95% CI 2.34-3.59).
  
  
  CONCLUSIONS
  Incidence rates for differentiated thyroid carcinomas are increasing among children and adolescents and young adults in the US. The increasing trends for larger tumors rules out diagnostic scrutiny as the only explanation for the observed results. Environmental, dietary, and genetic influences should be investigated.
authors.affiliation: Faculty of Medical Sciences of Santa Casa of São Paulo, São Paulo, Brazil.
authors.forename: Lucas Bonachi
authors.initials: LB
authors.lastname: Vergamini
authors.affiliation: Dana-Farber/Boston Children's Center for Cancer and Blood Disorders and Harvard Medical School, Boston, MA.
authors.forename: A Lindsay
authors.initials: AL
authors.lastname: Frazier
authors.affiliation: Faculty of Medical Sciences of Santa Casa of São Paulo, São Paulo, Brazil.
authors.forename: Fernanda Laurinavicius
authors.initials: FL
authors.lastname: Abrantes
authors.affiliation: Faculty of Medical Sciences of Santa Casa of São Paulo, São Paulo, Brazil.
authors.forename: Karina Braga
authors.initials: KB
authors.lastname: Ribeiro
authors.affiliation: Dana-Farber/Boston Children's Center for Cancer and Blood Disorders and Harvard Medical School, Boston, MA. Electronic address: carlos_rodriguez-galindo@dfci.harvard.edu.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodriguez-Galindo
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012042:Registries; D018570:Risk Assessment; D018426:SEER Program; D017678:Sex Distribution; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult