Prognostic Value of Number of Metastatic Nodes in School-Age Children and Adolescents With Papillary Thyroid Cancer: A Real-Life Multicenter Study.

Background

How metastatic nodal burden influences the prognosis of school-age children and adolescents (SACAs) with papillary thyroid cancer (PTC) remains unclear. We investigated the independent impact of numerical metastatic nodal burden on clinical outcomes in these patients.

Materials And Methods

This multicenter retrospective cohort study included SACAs with PTC aged 18 years and older who had undergone total thyroidectomy and radioiodine therapy across 12 nuclear medicine departments in China. Persistent biochemical and structural diseases were evaluated. The independent role of metastatic nodes in persistent disease was evaluated using Cox proportional hazards regression.

Results

In total, 486 SACAs with PTC were analyzed, of whom 115 had N1a and 371 had N1b. Among SACAs with N1b PTC, a higher number of metastatic lymph nodes, analyzed as a continuous variable, was identified as an independent risk factor for persistent structural disease (HR: 1.06; 95% CI: 1.01-1.11). When analyzed as a categorical variable, patients in the third (16-22 nodes) and fourth (>22 nodes) quartiles of the number of metastatic nodes exhibited an increased hazard of persistent structural disease (HR: 3.35; 95% CI: 1.13-9.97; P=0.029 and HR: 5.52; 95% CI: 1.59-19.13; P=0.007, respectively). ROC analysis identified a cutoff of ≥14 metastatic lymph nodes for predicting persistent structural diseases. However, for SACAs with N1a PTC, analysis of the number of metastatic nodes revealed no association with persistent disease.

Conclusions

The number of metastatic nodes is a predominant factor associated with persistent disease, and incorporating quantitative assessment of metastatic nodes may improve risk stratification in SACAs with N1b PTC.