PATHOLOGIC FEATURES ASSOCIATED WITH MOLECULAR SUBTYPES OF WELL-DIFFERENTIATED THYROID CANCER

Objective To determine the association between pathologic features and molecular classes (BRAF-like, RAS-like, and non-BRAF-like non-RAS-like [NBNR]). Methods Retrospective review of a merged database containing 676 patients, 84% (571/676) were assigned to a molecular class from publicly accessible sequenced data of thyroid neoplasms. Results The merged cohort included 571 neoplasms: 353 (62%) BRAF-like, 172 (30%) RAS-like, and 46 (8.1%) NBNR. Lymph node metastasis (any N1 disease) was present in 166/337 (49%) of BRAF-like, 23/164 (14%) of RAS-like, and 0/46 (0%) of NBNR and are significantly different (P Conclusion Pathological features of metastasis, gross extra-thyroidal extension, and multifocality were more prevalent in BRAF-like samples compared to RAS-like and NBNR. A trend towards increased frequency of angioinvasion in RAS-like and NBNR cancers compared to BRAF-like samples was observed. Further studies are needed to evaluate if preoperative knowledge of molecular mutations in thyroid tumors aids in decision-making regarding extent of surgery.