Abstract
BACKGROUND: The incidence of pediatric thyroid cancer increases sustainably in the past years. Pediatric thyroid cancer is different from adult thyroid cancer in pathophysiology, clinical characteristics and others, which determines the different treatment methods for pediatric thyroid cancer and adult patients. In order to avoid the overtreatment of younger patients, this study aims to explore the effect of clinically pathological features on postoperative recurrence of thyroid cancer in younger patients. METHODS: A total of 234 patients ≤25 years and 311 patients >25 years of age with papillary thyroid carcinoma from Medical University Cancer Institute and Hospital were enrolled in the retrospective study. We retrospectively analyzed thyroid cancer patients, stratified by age (<18, 18-25, >25 years). Clinicopathological features were compared using log-rank tests; multivariable Cox regression identified recurrence predictors, and Kaplan-Meier analyses assessed recurrence-free survival (RFS). RESULTS: Patients aged <18 and 18-25 years showed comparable clinical characteristics (only sex distribution differed, P=0.02), supporting a unified children, adolescents, and young adult (CAYA) cohort (≤25 years). CAYA patients exhibited higher rates of bilateralism, multifocality, papillary thyroid microcarcinoma, extrathyroidal extension, lymphatic metastasis, and recurrence. Lymphatic metastasis [Exp(B) =6.818, P=0.009] and lateral cervical lymph node (LN) dissection [Exp(B) =3.044, P=0.005] were independent recurrence predictors. Lymphatic metastasis (presence, ≥5 nodes, or lateral location) correlated with poorer RFS (P≤0.006). CONCLUSIONS: LN metastasis is an important risk factor for postoperative recurrence in CAYA patients, suggesting that preoperative attention should emphasize the assessment of LN metastasis, including the number and area.