Role of Postoperative Stimulated Thyroglobulin as Prognostic Factor for Differentiated Thyroid Cancer in Children and Adolescents

Background: Prognostic factors are essential for risk stratification in patients with differentiated thyroid carcinoma (DTC). The role of stimulated postoperative thyroglobulin (sPOTg) has been well established in adult DTC population, but it remains unclear in children and adolescents. This study aimed to evaluate potential prognostic factors in children and adolescents with DTC, with special emphasis on sPOTg analysis. Methods: Individuals aged 18 years at diagnosis were selected from a cohort of DTC patients attending the thyroid clinic of a tertiary university-based hospital. Baseline clinical and oncological characteristics, interventions, disease status, and outcomes were obtained from medical records. Clinical variables included in the univariate analysis were sex, age at diagnosis, tumor size, the presence of lymph node and distant metastasis, and sPOTg. Additionally, sPOTg was evaluated using the area under the receiver operating characteristic curve analysis. Results: Thirty-two children and adolescents with DTC (28 girls, 87.5%; the mean age at diagnosis=14.73.2 years) were included in this study. Thirty-one (96.9%) patients had papillary thyroid carcinoma. The median tumor size was 2.0cm (P25-75=1.6-3.5), 22 patients (68.8%) had lymph node disease, and 5 (15.6%) had distant metastasis at diagnosis. All patients underwent total thyroidectomy, and 29 (90.6%) received radioactive iodine therapy. After a median follow-up of 5.0 years (P25-75=2.0-10.0), disease status was available for 27 patients: 15 (55.6%) patients were disease free, six (22.5%) had biochemical disease, and six (22.2%) had persistent structural disease (two cervical and four distant metastasis). Prognostic factors associated with persistent disease in the univariate analysis were lymph node and distant metastasis at diagnosis and sPOTg. According to the receiver operating curve analysis (n=17 patients), the best sPOTg cutoff to predict disease-free status was 31.5ng/mL, with a sensitivity and specificity of 100%. Conclusion: The data demonstrate that sPOTg displayed high accuracy in predicting the risk of persistent disease in young patients with DTC.