THU223 Molecular Makeup Of Differentiated Thyroid Carcinoma In A Free-standing Children’s Hospital With A Predominantly Hispanic Population
Authors: Martinez Andrea , Baboun Daniela , Solano Natalia , Restrepo Ricardo , Brathwaite Carole , Alkhoury Fuad , Carrillo-Iregui Adriana 
Published: October 2023

Abstract
Disclosure: A. Martinez: None. D. Baboun: None. N. Solano: None. R. Restrepo: None. C. Brathwaite: None. F. Alkhoury: None. A. Carrillo-Iregui: None.
Background: Molecular testing has been incorporated into the clinical management of thyroid nodules in adults. The prevalence of oncogenic mutations and the role of molecular testing in the evaluation of thyroid nodules in children and adolescents have yet to be established. Objective: The purpose of this study is to identify the molecular makeup of thyroid nodules in patients diagnosed with differentiated thyroid carcinoma (DTC) at a free-standing children’s hospital with a predominantly Hispanic population. Methods: Upon Institutional Review Board approval, we reviewed the charts of all patients with a final diagnosis of DTC between 2012 and 2022. We analyzed demographics, histopathological diagnoses, and molecular oncogenic markers of pathology specimens when available. Statistical analysis was performed using Welch’s t-test and Fisher’s exact test. Results: Fifty-five patients between 8-20 years of age were diagnosed with DTC. Forty-nine (89.1%) patients identified as Hispanic, and 41 (74.6%) were females. Fifty-two (94.5%) patients had papillary thyroid carcinoma, and 3 (5.5%) had follicular thyroid carcinoma. Molecular testing was performed on 33 patients, of which 30 were positive for mutations and 3 undetected. BRAF V600E (43.3%) and RET/PTC (23.3%) were the most prevalent mutations detected. The average ages of patients with BRAF V600E and RET/PTC were 15.5 and 13.3 years, respectively with no statistical significance (p=.22). The average tumor sizes of patients with BRAF V600E and RET/PTC were 1.82 ± 0.95 cm and 2.5 ± 1.21 cm, respectively with no statistical significance (p=.12). Of the patients with BRAF V600E, 53.9% had lymph node involvement and none had metastasis. Of the patients with RET/PTC, 42.9% had lymph node involvement and 14.3% had metastasis. When comparing BRAFV600E and RET/PTC, there was no statistical difference with respect to lymph node involvement or metastasis (p=1.0 and p=.35, respectively). Other mutations detected include PAX8-PPARg (10.0%), ALK fusion (6.7%), RAS (3.3%), PTEN (3.3%), compound KIT and TSHR (3.3%), TRIM27-RET (3.3%), and other (3.3%). Notably, one patient presented with TRIM27-RET, which was associated with total lobe involvement, lymph node involvement, and distal metastasis. Conclusions: BRAF V600E and RET/PTC were the most prevalent molecular markers correlated with DTC in our predominantly Hispanic cohort. In comparison to BRAF V600E, RET/PTC was more prevalent in younger patients and was associated with a greater tumor size. We did not find any statistically significant differences with respect to age, tumor size, lymph node involvement, or metastasis between the aforementioned molecular markers. Incorporating molecular testing to supplement malignancy evaluation may improve clinical and surgical management for pediatric patients with DTC.
Presentation: Thursday, June 15, 2023