Characterization of Advanced RAS-driven Follicular-derived Thyroid Cancers and Review of Future Therapeutic Avenues.

Abstract

With novel RAS-targeted therapies emerging, better understanding of RAS-driven differentiated (DTC) and anaplastic (ATC) thyroid cancers is warranted. Characterize the genotypic and phenotypic landscape of RAS-driven DTC and ATC and review current and future therapeutic avenues. Retrospective chart review between January 2015 and June 2023. Median follow-up duration 8.4 years in DTC cohort and 36.4 months in ATC cohort. Single-center study at MD Anderson Cancer Center. Individuals with RAS-altered DTC or ATC identified before kinase inhibitor exposure. None. Primary objective was to describe clinical and molecular characteristics. Secondary objectives included identifying prognostic factors and assessing survival outcomes with available therapies. Among 120 RAS-driven DTC and 71 RAS-driven ATC, NRAS was the most common alteration (69% of DTC, 70% of ATC), mainly at residue Q61. Brain metastases were found in 22% of patients undergoing brain imaging (19% in DTC, 25% in ATC). Median overall survival (OS) was 15.2 years in DTC, with 49% of patients receiving at least 1 line of systemic therapy, most commonly lenvatinib (66%). Median time to systemic therapy was 3.5 years from diagnosis, and median OS from therapy initiation was 6.0 years. In ATC, median OS was 7.5 months. Stage IVC [hazard ratio (HR) = 6.78)], neck surgery (HR = 0.29), and exposure to immunotherapy (HR = 0.13) were significantly associated with mortality. Advanced RAS-driven follicular-derived thyroid cancers seem to exhibit an aggressive behavior, particularly in ATC, in which prognosis remains poor despite expert multidisciplinary care. Advances in RAS-targeted therapies offer hope for improved therapeutic options.