Endocrine Abstracts

Objectives: Differentiated thyroid cancer (DTC) is rare in childhood and adolescence. However, its incidence increases by 1.1% per year, rendering it the most common pediatric endocrine neoplasia, representing 3% of all pediatric malignancies. The aim of the study is to present the data of pediatric patients with DTC followed in our institution.

Methods: Patients with DTC who were diagnosed and treated in our division between 2017 and 2024 were enrolled in the study. All patients were under 18 years old. Data regarding demographics, treatment, and follow-up outcomes were retrospectively collected.

Results: Thirty-one patients with a median age at presentation of 13 years (range, 7 to 17) were recruited [9 boys (29%)/ 22 girls (71%)]. According to BMI z score 52% had normal weight, 35% were overweight and 13% obese while the respective distribution in the general pediatric Greek population is 27,5% normal weight, 37.5% overweight and 35% obese. Most of our them (93%) originated from central and South Greece while 35% (11/31) had a positive family history for thyroid cancer. Total thyroidectomy, with central and/or lateral neck dissection, when needed, was performed. Histological examination revealed DTC in all patients, 25 of whom with classic variant of PTC and 5 an aggressive type of PTC. Data is missing in one patient. 84% of our cases were treated with RAI therapy according to histological findings while one is still pending. A total of 7 patients were lost to follow-up while 5 patients were diagnosed within the last year. 54% of the patients (13/24) with a follow-up of >1year had an excellent outcome. Three patients (12%) underwent a second RAI therapy due to persistence of the disease, while 4 (17%) had a closer follow-up due to persistence of thyroglobulin levels between 0.2 and 1 ng/ml and/or persistence of anti-TG positivity albeit with stable or declining levels during follow-up.

Conclusions: Our study confirms the increasing incidence of DTC among children and adolescents during the last years with an average of 4.4 new cases yearly albeit with an excellent outcome. Further studies are needed to identify possible causes and risk factors. Total thyroidectomy followed by RAI, only when indicated, is the recommended treatment for patients with pediatric DTC in terms of reducing relapse rate and improving surveillance for recurrent disease without increasing the risk of long-term complications of RAI treatment in young patients who will not benefit of a higher-intensity treatment approach.