title: Management of metastatic thyroid cancer in pregnancy: risk and uncertainty.
abstract: Metastatic thyroid cancer is an uncommon condition to be present at the time of pregnancy, but presents a challenging paradigm of care. Clinicians must balance the competing interests of long-term maternal health, best achieved by iatrogenic hyperthyroidism, regular radioiodine therapy and avoidance of dietary iodine, against the priority to care for the developing foetus, with inevitable compromise. Additionally, epidemiological and cellular data support the role of oestrogen as a growth factor for benign and malignant thyrocytes, although communicating the magnitude of this risk to patients and caregivers, as well as the uncertain impact of any pregnancy on long-term prognosis, remains challenging. Evidence to support treatment decisions in this uncommon situation is presented in the context of a case of a pregnant teenager with known metastatic papillary thyroid cancer and recent radioiodine therapy.
  
  
  CONCLUSIONS
  Pregnancy is associated with the growth of thyroid nodules due to stimulation from oestrogen receptors on thyrocytes and HCG cross-stimulation of the TSH receptor.Thyroid cancer diagnosed during pregnancy has not been shown to be associated with increased rates of persistent or recurrent disease in most studies.There is little evidence to guide the management of metastatic thyroid cancer in pregnancy, where both maternal and foetal wellbeing must be carefully balanced.
authors.affiliation: Departments of Endocrinology and Diabetes; Schools of Medicine and Public Health.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Rowe
authors.affiliation: Departments of Endocrinology and Diabetes.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Murray
authors.affiliation: Maternity and Gynaecology , John Hunter Hospital, Newcastle, New South Wales , Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Woods
authors.affiliation: Department of Nuclear Medicine & PET, Hunter New England Imaging, John Hunter and Calvary Mater Hospital, Newcastle, New South Wales, Australia; Health Sciences, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Departments of Endocrinology and Diabetes; Schools of Medicine and Public Health.
authors.forename: Roger
authors.initials: R
authors.lastname: Smith
authors.affiliation: Departments of Endocrinology and Diabetes; Schools of Medicine and Public Health.
authors.forename: Katie
authors.initials: K
authors.lastname: Wynne