title: Clinical and molecular features of differentiated thyroid cancer diagnosed during pregnancy.
abstract: OBJECTIVE
  Pregnancy represents a favorable condition for the development of thyroid nodules, likely due to the secretion of hormones with stimulatory activity. In particular, differentiated thyroid cancer (DTC) represents the second most frequent tumor among those diagnosed during pregnancy. However, few and discordant data are available about the impact of pregnancy on tumor outcome.
  
  
  METHODS
  A total of 123 women with DTC were divided into three groups according to the timing of tumor diagnosis (group 1, at least 1 year after the delivery; group 2, during pregnancy or in the first year after delivery; and group 3, before pregnancy or nulliparity) and evaluated according to the international guidelines. Furthermore, immunohistochemical studies of estrogen receptor alpha (ERalpha) were performed in 38 papillary thyroid cancer tissues from the three groups.
  
  
  RESULTS
  Thyroid cancer diagnosed during pregnancy was associated with a poorer prognosis compared to tumors developed in nongravidic periods (P<0.0001). Accordingly, at the stepwise logistic regression analysis, the diagnosis of DTC during pregnancy or in the first year post partum was the most significant indicator of persistent disease (P=0.001). Interestingly, ERalpha expression significantly differed among tumors of the three groups, being detected in 31% of group 1, in 87.5% of group 2, and in 0% of group 3 (P=0.01).
  
  
  CONCLUSIONS
  Present data indicate that pregnancy has a negative impact on the outcome of thyroid cancer. The presence of ERalpha in the majority of tumors diagnosed during pregnancy indicates that the poorer outcome of these cases could be related to the estrogen-mediated growth stimulus.
authors.affiliation: Department of Medical Sciences, University of Milan, Fondazione Policlinico IRCCS, Milan, Italy.
authors.forename: Guia
authors.initials: G
authors.lastname: Vannucchi
authors.forename: Michela
authors.initials: M
authors.lastname: Perrino
authors.forename: Stefania
authors.initials: S
authors.lastname: Rossi
authors.forename: Carla
authors.initials: C
authors.lastname: Colombo
authors.forename: Leonardo
authors.initials: L
authors.lastname: Vicentini
authors.forename: Davide
authors.initials: D
authors.lastname: Dazzi
authors.forename: Paolo
authors.initials: P
authors.lastname: Beck-Peccoz
authors.forename: Laura
authors.initials: L
authors.lastname: Fugazzola
mesh_terms: D000328:Adult; D002454:Cell Differentiation; D049109:Cell Proliferation; D047628:Estrogen Receptor alpha / Q000032:analysis; D004967:Estrogens / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology* / Q000601:surgery
chemical_list: D047628:Estrogen Receptor alpha; D004967:Estrogens