SAT523 Molecular Profile of Local vs. Regional Aggressive Thyroid Cancer: A Multicenter Study

Abstract

Abstract Disclosure: I. Tessler: None. N. Gecel: None. R. Payne: None. G. Avior: None. A. Eran: None. Background: Genetic testing for the diagnosis of thyroid cancer has rapidly evolved in recent years. While commonly applied for diagnosis, its role in predicting genotype-phenotype correlation and guiding management is emerging. Here we evaluate differences in the molecular profile of local vs. regional aggressive disease. Methods: We performed a retrospective multicenter study of patients who underwent molecular profiling for DTC between 2018-2021, dividing them into three groups: low-risk, locally aggressive, and regional aggressive. We analyzed the patients' basic characteristics, disease aggressive features (extranodal extension, perineural invasion), lymphovascular invasion, and extrathyroidal extension), and the mutation distribution according to disease aggressiveness. Genetic variants were stratified by risk levels according to the 2015 ATA guidelines. Results: The study included a total of 652 patients, 414 in the low-risk group, 73 in the locally aggressive group, and 165 in the regional aggressive group. The regional aggressive group had the lowest age at diagnosis (mean age of 44.64±13.78 years vs. 52.52±14.53 and 53.58±14.93 for the low-risk and locally-aggressive, respectively, p>0.001), the highest rate of mutation-positive nodules (86.1% vs. 6.6% and 67.1%), and the highest rate of aggressive mutation (76.4% vs. 17.6 and 39.7). On the contrary, RAS mutations were more common in the low-risk (31.4% vs. 19.2% and 6.1% in the local- and regional aggressiveness groups). Conclusion: This study showed that local and regional aggressive thyroid cancer has a distinct molecular profile, with a higher prevalence of high-risk mutations in the regional group. These findings may enhance the use of genetic testing in predicting disease aggressiveness and guiding management in thyroid cancer. Presentation Date: Saturday, June 17, 2023