Thyroid Cancer In Children: A Multicenter International Study
Highlighting Clinical Features And Surgical Outcomes Of Primary And
Secondary Tumors
Abstract
Background: Thyroid gland malignancy is rare in pediatrics (0.7% of
tumors); only 1.8% are observed in patients < 20 yrs with a
higher prevalence recorded in females and adolescents. Risk factors
include genetic syndromes - MEN disorders, autoimmune disease and
ionizing radiation exposure. Radiotherapy is also linked with increased
risk of secondary thyroid cancers. The present study describes the
clinical features and surgical outcomes of primary and secondary thyroid
tumors. Methods: Institutional data was collected on pediatric patients
with thyroid cancer during 2000 - 2020 from 8 International Surgical
Oncology centers. Statistical analysis was performed using GraphPad
Prism. Results: Of 255 cases of thyroid cancer, only 13 (5.1%) were
secondary tumors. Primary thyroid malignancies were more likely to be
multifocal in origin (odds ratio [OR] 1.993, 95% confidence
interval [CI] 0.7466-5.132, p 0.2323), had bilateral glandular
location (OR 2.847, 95% CI 0.6835-12.68, p 0.2648) and proved
metastatic at 1st diagnosis (OR 1.259, 95% CI 0.3267-5.696
p>0.999). Secondary tumors showed a higher incidence of
disease relapse (OR 1.556, 95% CI 0.4579-5.57, p 0.4525) and surgical
morbidity (OR 2.042, 95% CI 0.7917-5.221, p 0.1614) including
hypoparathyroidism and recurrent laryngeal nerve injury. Overall
survival (OS) was 99% at 1 year and 97% after 10 years. No EFS
differences were evident with primary vs. secondary tumors (Chi square
0.7307, p 0.39026). Conclusions: This multicenter study demonstrates
excellent survival for pediatric thyroid malignancy. Secondary tumors
exhibit greater disease relapse (15.8% vs 10.5%) and a higher
incidence of surgical related complications (36.8% vs 22.2%).