title: Prognostic Factors for Early and Long-Term Remission in Pediatric Differentiated Thyroid Carcinoma: The Role of Sex, Age, Clinical Presentation, and the Newly Proposed American Thyroid Association Risk Stratification System.
abstract: The incidence of pediatric differentiated thyroid carcinoma (DTC) has been rising in recent years, and the main risk factors for recurrence are lymph node and distant metastasis at diagnosis. Other clinical features remain unclear, such as the impact of age, sex, and puberty. Furthermore, until now, this population has been treated using the same strategies used to treat adults. In 2015, the American Thyroid Association (ATA) published the first guidelines targeted at this age group. The aims of this study were to investigate the prognostic factors for early and long-term remission and also to validate the ATA risk stratification proposal in a population outside the United States.
  
  
  
  Clinical records from 118 patients <18 years old followed in two referral centers were reviewed. The median age was 12 years (range 4-18 years), and 20.3% (24 patients) were <10 years old at diagnosis. The median follow-up was 9.1 years. The majority were female (72%) and received total thyroidectomy and radioiodine therapy (RAI), and 61.8% were treated with more than one dose of RAI. The majority were classified as high risk (48.3%) by the new ATA pediatric guidelines due to distant metastasis (30 patients) or extensive lymph node involvement (27 patients). The remained were classified as low risk (31.3%) and intermediate risk (20.4%).
  
  
  
  Females with no lymph node or distant metastasis and low ATA pediatric risk were more likely to have no evidence of disease (p < 0.05) within the first year and also in the long term. In this study, age did not significantly predict outcomes. Furthermore, patients also benefitted from multiple doses of RAI, but when the cumulative activity was >400 mCi, this benefit was diminished.
  
  
  
  This study shows that the ATA risk stratification proposal for pediatric patients is useful in predicting early and long-term outcomes in pediatric patients with DTC. In addition, it shows that sex and metastatic disease are important prognostic factors in pediatric populations.
authors.affiliation: 1 Endocrinology Department, Universidade Federal do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Barbara Pereira
authors.initials: BP
authors.lastname: Pires
authors.affiliation: 2 Endocrinology Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Paulo Alonso Garcia
authors.initials: PA
authors.lastname: Alves
authors.affiliation: 2 Endocrinology Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Maria Alice
authors.initials: MA
authors.lastname: Bordallo
authors.affiliation: 2 Endocrinology Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Daniel Alves
authors.initials: DA
authors.lastname: Bulzico
authors.affiliation: 3 Nuclear Medicine Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Flavia Paiva Proença Lobo
authors.initials: FP
authors.lastname: Lopes
authors.affiliation: 4 Head and Neck Surgery Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Terence
authors.initials: T
authors.lastname: Farias
authors.affiliation: 4 Head and Neck Surgery Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Fernando
authors.initials: F
authors.lastname: Dias
authors.affiliation: 4 Head and Neck Surgery Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Roberto Araújo
authors.initials: RA
authors.lastname: Lima
authors.affiliation: 4 Head and Neck Surgery Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Izabella Costa
authors.initials: IC
authors.lastname: Santos Gisler
authors.affiliation: 5 Institute of Public Health Study, Universidade Federal do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Claudia Medina
authors.initials: CM
authors.lastname: Coeli
authors.affiliation: 6 Instituto de Pesquisa Clínica Evandro Chagas , Fundação Oswaldo Cruz, Rio de Janeiro, Brazil .
authors.forename: Raquel Vasconcellos
authors.initials: RV
authors.lastname: Carvalhaes de Oliveira
authors.affiliation: 2 Endocrinology Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Rossana
authors.initials: R
authors.lastname: Corbo
authors.affiliation: 1 Endocrinology Department, Universidade Federal do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Mario
authors.initials: M
authors.lastname: Vaisman
authors.affiliation: 2 Endocrinology Department, Instituto Nacional do Cancer do Rio de Janeiro , Rio de Janeiro, Brazil .
authors.forename: Fernanda
authors.initials: F
authors.lastname: Vaisman
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D017410:Practice Guidelines as Topic; D011379:Prognosis; D012074:Remission Induction; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D012955:Societies, Medical; D016019:Survival Analysis; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D047368:Tumor Burden; D014481:United States