[Analysis of clinicopathological characteristics and prognosis of papillary thyroid carcinoma in children and adolescents at different ages].

Objectives: To examine the age cut-off point for poor clinicopathological characteristics and prognosis of differentiated thyroid carcinoma (DTC) in children and adolescents. Methods: The clinicopathological features of 74 patients with DTC aged 18 years and younger who underwent surgery in the Department of Thyroid Surgery, the First Hospital of China Medical University from January 2011 to December 2020 were retrospectively analyzed. There were 20 males and 54 females, aged (M(IQR)) 16 (4) years (range: 8 to 18 years). Firstly, the cut-off point of age affecting prognosis was determined according to the receiver operator characteristic curve, the patients included in the study were grouped according to the age cut-off, and then the univariate and multivariate analysis for prognostic factors were performed using the Cox risk proportional regression model. The Kaplan-Meier survival curve was used to verify the factors affecting the prognosis and analyzed the possible mechanisms by bioinformatics. Results: The cut-off value of age was 15 years. Age ≤15 years was the only prognostic factor for recurrence (HR=4.427, 95%CI: 1.236 to 15.859, P=0.022). The number of metastatic cervical lymph nodes was higher in patients aged ≤15 years, and the 10-year recurrence-free survival rate was much lower than in patients aged >15 years (50.4% vs. 84.1%, P=0.018). Gene enrichment analysis and differential gene identification showed that differential genes between ≤15 years old group and>15 years old group were closely related to the transforming growth factor-β signaling pathway and some metabolism-related signaling pathways. Conclusions: Age ≤15 years is the only prognostic factor for the prognosis of DTC in children and adolescents. Age ≤15 years had more cervical lymph node metastases and a worse prognosis. For younger DTC patients, more active treatment and a stricter postoperative management strategy should be adopted.