CEFYBO   02669
CENTRO DE ESTUDIOS FARMACOLOGICOS Y BOTANICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Analysis Of BRAF And NRAS Mutations In Fine-needle Aspiration Thyroid Nodule Samples And Its Association With Follicular Lesion
Autor/es:
BOXER M; RUDA VEGA V; REPETTO EM; LAMBERTINI R; FAURE E; ARANDA C; DEL VALLE JAEN; ONETO A
Lugar:
Chicago, Illinois
Reunión:
Congreso; 100th Annual Meeting of The Endocrine Society; 2018
Institución organizadora:
The Endocrine Society
Resumen:
The relevance in the study of the thyroid nodule lies in the exclusion of a malignant lesion, although most of the lesions are benign, there is certain risk. When dealing with follicular lesions found in a fine- needle aspiration (FNA), the supplementary analysis of molecular markers such as mutations in gene RAS is suggested. Nevertheless, the distribution of the mutations found in the different isoforms of RAS (NRAS, HRAS and KRAS), as well as its clinical impact in the different types of thyroid pathology, are widely distributed among the different populations studied. Taking into consideration that there is not any previous report of the analysis of the mutations in Argentina, our objective was to research the presence of mutations in BRAF and NRAS in a series of FNA samples with different thyroid lesions. Mutations in BRAF V600E and in the 61 codon of NRAS were detected through real time PCR, and melting curves analyisis was assessed with specific probes in genomic DNA samples extracted from the residual material of 36 FNA samples from patients whom had the indication for a cytological study. The result obtained was compared with its corresponding histological report. Out of the 36 FNA samples analyzed, 30 were related with papillary thyroid carcinoma (PTC) from different subtypes (classic, follicular or sclerosing), 3 related with follicular thyroid carcinoma (FTC) minimally invasive and 3 samples were correlated with follicular adenoma (FA). All the samples from patients with PTC were NRAS negative, whereas 24 of these were BRAF positive and 6 were negative for the mutation, while in the patients with FTC, 1/3 of the samples were NRAS positive, being all of them negative for BRAF V600E with a Bethesda IV category in the FNA analysis. Finally, all of the FA patients turned out to be negative for both mutations. This preliminary study shows that the BRAF V600E mutation was only present in patients with PTC, while the NRAS mutations, usually associated with thyroid lesions with follicular pattern, was found in an unique sample from a patient with FTC. Even though the low prevalence of FTC in the samples studied limits the study conclusions, the mutational status of BRAF and NRAS could complement the cytological analysis and makes necessary the further investigation in different described mutations (for instance, RAS isoforms).