Differentiated Thyroid Cancer Long-Term Outcomes and Risk Stratification in Pediatric and Adolescent Patients: A 44-Year Retrospective Study.

Differentiated thyroid cancer (DTC) in children and adolescents is a rare but significant malignancy, often presenting at more advanced stages compared to adults, although it is associated with favorable long-term outcomes. This study aimed to identify prognostic factors and perform risk stratification with the goal of identifying low-risk patients who would benefit from a less radical treatment approach. This retrospective cohort study included patients aged 21 years and younger with DTC treated at the Institute for Oncology and Radiology of Serbia between 1980 and 2024. The study analyzed 99 patients (39 children, 60 adolescents) with a median follow-up of 15.6 years (range: 0.6-43.6 years). No significant differences in long-term outcomes were observed between children and adolescents. Multivariate regression analysis identified a total number of more than 10.5 positive lymph nodes and extrathyroidal tumor extension as independent predictors of adverse events and event-free interval (EFI). Using these prognostic factors, patients were stratified into three groups: low-risk (no risk factors), intermediate-risk (one of two risk factors), and high-risk (both risk factors). Statistically significant differences in EFI were observed among the three groups. Notably, none of the patients in the low-risk group had evidence of disease after treatment. Patients classified as having no evidence of disease after treatment demonstrated significantly better EFI compared to those with evidence of disease. Our findings highlight the importance of meticulous risk stratification in predicting long-term outcomes and might serve as a basis for developing personalized therapeutic strategies. Identifying low-risk patients who may benefit from a less aggressive treatment approach while ensuring optimal treatment and follow-up for high-risk patients remains a central objective in the modern management of DTC.