Prognostic value of pre-ablation stimulated thyroglobulin in children and adolescents with differentiated thyroid cancer

Aim: To investigate the prognostic value of pre-ablation stimulated thyroglobulin (ps-Tg) in children and adolescents with persistent differentiated thyroid cancer (DTC) following initial radioiodine therapy (RAI). Materials & Methods: Patients were classified into "no clinical evidence of disease" (NED), "biochemical persistent disease" (BPD), and "structural/functional persistent disease" (S/FPD) groups, based on their therapeutic response to initial RAI. BPD patients were further categorized as incomplete response (IR) or Non-IR; S/FPD patients were categorized as remission or Non-remission. Receiver operating characteristic (ROC) curves were used to assess the predictive value of ps-Tg for long-term prognosis. Univariate and multivariate regression analyses were performed to identify risk factors for IR in BPD group and Non-remission in S/FPD group. Results: In total, 130 patients were included, with NED (32), BPD (61), and S/FPD (37) patients. Multivariate analysis identified therapeutic response to initial RAI as the only independent predictor of IR in the BPD group. ROC analysis determined an optimal ps-Tg threshold of 112.40 ng/mL for predicting Non-remission in S/FPD patients. Multivariate analysis further confirmed that ps-Tg > 112.4 ng/mL was significantly associated with Non-remission. Conclusions: Findings indicate ps-Tg as a valuable predictor of long-term prognosis in children and adolescents with persistent DTC post initial RAI. This study investigates how pre-ablation stimulated thyroglobulin (ps-Tg) levels can predict long-term outcomes in children and adolescents with persistent differentiated thyroid cancer (DTC) after initial radioiodine therapy (RAI). A total of 130 patients were categorized into three groups based on their response to RAI: no clinical evidence of disease (NED), biochemical persistent disease (BPD), and structural/functional persistent disease (S/FPD). The results showed that patients with higher ps-Tg levels were more likely to have persistent or progressive disease. A ps-Tg threshold of 112.4 ng/mL was identified as a significant predictor of non-remission in S/FPD patients. Additionally, ps-Tg levels were associated with the likelihood of distant metastasis, with a cut-off value of 98.0 ng/mL providing high predictive accuracy. These findings highlight ps-Tg as a reliable marker for identifying patients at higher risk of poor outcomes. This knowledge can help clinicians personalize treatment strategies, focusing resources on those who require closer monitoring and aggressive intervention.