The Prognostic Significance of Extranodal Extension in Papillary Thyroid Cancer: A Real-World Study

Abstract

Background: The prognostic significance of extranodal extension in papillary thyroid cancer remains controversial. Methods: Seven hundred and thirty-eight PTC patients were enrolled in the study from January 2016 to December 2019. Patients were dichotomized with or without ENE. Univariate and multivariate logistic analyses were used to compare differences between the two groups. Kaplan-Meier (K-M) curve and propensity score matching analysis were used for recurrence-free survival comparison. Result: Thirty patients (4.07%) had associated extranodal extension. Univariate analysis demonstrated age, tumor size, extrathyroidal extension, nodal staging to be associated with ENE. Further logistic regression analysis showed age, extrathyroidal extension and nodal staging remained statistically significant. Evaluation of K-M curves demonstrated a statistically significant difference was found between two groups before and after propensity score matching. Conclusions: Age≥55years, extrathyroidal extension, and lateral cervical lymph node metastasis have been identified as independent risk factors of ENE. PTC patients with ENE have worse recurrence-free survival. Funding: This work is supported by Science Research Program of Hangzhou(20180533B39), the Project of Medical Scientific and Technology Program in Hangzhou (grant number A20200432), and the Medical and Health Research Program of Zhejiang Province (2019RC240). Declaration of Interest: The authors declare no conflict of interests. Ethical Approval: The present study was approved by the Ethics Committee of our institution (Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine).