Mutação BRAF em pacientes idosos submetidos à tireoidectomia

Abstract

Mutação BRAF em pacientes idosos submetidos à tireoidectomia Mutação BRAF em pacientes idosos submetidos à tireoidectomia Mutação BRAF em pacientes idosos submetidos à tireoidectomia Mutação BRAF em pacientes idosos submetidos à tireoidectomia Mutação BRAF em pacientes idosos submetidos à tireoidectomia ANTONIO Results ResultsResults Results: The study detected the presence or absence of BRAF V600E mutation in 47 patients (55.3%). Among the 17 papillary carcinomas studied, seven had the mutation (41.2%). There was a statistical association between the presence of this mutation and the classic variant of papillary carcinoma, and a trend of association with thyroid extravasation. Conclusion Conclusion Conclusion Conclusion Conclusion: BRAF mutation in the elderly is also exclusive of papillary carcinoma and is often significant. Furthermore, it is related to the classic variant and possibly to thyroid extravasation. 1 . An important study showed BRAF mutations in thyroid cancer, with prevalence lower only than the one of melanoma 2 . Mutations in BRAF gene (B-type RAF kinase gene) represent the most common genetic disorders of thyroid cancer and this was the most striking finding in this research field in the last years 3 . The discovery of these changes created the opportunity for developing new treatment strategies for thyroid cancer 4,5 . They are present between 23 and 83% of papillary carcinomas and are highly specific for this histological type 2,[6][7][8] . Kimura et al., in a pioneer study published in 2003, demonstrated that the BRAF mutation occurs in 32.8% of papillary carcinoma, does not occur in benign or follicular lesions and, when present, does not overlap with other RAS mutations or rearrangement of the RET/PTC. These facts point to the MAP kinase pathway as the main responsible for the genesis of papillary carcinoma 2 .This tumor has some histological variants that have also been studied for the presence of BRAF mutations. The classic variant and tall cell variant (related to higher aggression) seem to display a higher incidence of BRAF mutation. The follicular variant, on its turn, rarely presents with such a mutation. The microcarcinomas (tumors smaller than 1.0 cm) may also display it, which confirms the hypothesis that it occurs early in tumorigenesis of papillary carcinoma 9 . As for prognosis, this mutation may appear early in small papillary carcinomas, but it is believed that those with BRAF mutations are associated with poor prognosis and more aggressive variants (eg, tall cell), thyroid extravasation, more advanced clinical stage, distant metastasis and they can still be related to anaplastic carcinoma. These data indicate that tumors with this genotype have a worse prognosis 6,7,[9][10][11] . A correlation was demonstrated between age and the presence of BRAF mutation in papillary carcinomas 9,12 and low frequency in children 10,13 . Currently, no other clear association has been established between genotype and clinico-pathologic changes of papillary 12, among others 8,16,17 , sho...