THU681 Change In The Clinicopathological Characteristics And Outcomes Of Pediatric Thyroid Carcinoma In Korea: Focusing On Data From A Tertiary Hospital In Korea

Disclosure: J. Yoo: None. D. Leem: None. H. Ryu: None. H. Park: None. J. Kim: None. Y. Oh: None. T. Kim: None. S. Kim: None. J.H. Chung: None. Introduction: The incidence of thyroid carcinoma in adults in Korea increased until 2012, but has declined rapidly since then. However, the incidence of pediatric thyroid carcinoma increased until 2013, decreased slightly, and then increased again. Changes in the clinicopathological characteristics of pediatric thyroid carcinoma over time have not yet been elucidated. In this study, we aimed to evaluate the changes in the clinicopathological characteristics and outcomes of pediatric thyroid carcinoma from 1995 to 2022. Subjects and Methods: A total of 170 patients under the age of 19 years who were diagnosed with differentiated thyroid carcinoma at tertiary hospital in Seoul, Korea were enrolled. The patients were divided into four groups based on the year of initial surgery: 1995 – 2005 (n = 33), 2006 – 2010 (n = 46), 2011 – 2015 (n = 57), and 2016 – 2022 (n = 34). Results: The age at diagnosis, gender, primary tumor size, T stage, N stage, and M stage did not significantly differ among the four groups. Also, there was no significant difference over time in the route of detection (symptomatic vs. asymptomatic; P for trend = 0.519). The incidence of diffuse sclerosing variant of papillary thyroid carcinoma tended to increase over time (P=0.06). Surgical extent (P for trend = 0.001) and cumulative radioactive iodine (RAI) dose (P for trend < 0.001) significantly decreased over time. Nevertheless, the disease-free survival among the four groups did not change during the median follow-up 115.5 (62.3 – 155.3) months (log-rank P = 0.451). Conclusions: Although the overall incidence of pediatric thyroid carcinoma is gradually increasing in Korea, surgical extent and cumulative RAI dose significantly decreased and the clinicopathological characteristics and the disease-free survival did not change over time. Presentation: Thursday, June 15, 2023