Type and prevalence of BRAF mutations are closely associated with papillary thyroid carcinoma histotype and patients’ age but not with tumour aggressiveness.

Autor: Vítor Trovisco, Paula Soares, Ana Preto, Inês Vieira de Castro, Jorge Lima, Patrícia Castro, Valdemar Máximo, Tiago Botelho, Severina Moreira, Ana Margarida Meireles, João Magalhães, Alexander Abrosimov, José Cameselle-Teijeiro, Manuel Sobrinho-Simões
Zdroj: Virchows Archiv: European Journal of Pathology; Jun2005, Vol. 446 Issue 6, p589-595, 7p
Abstrakt: Abstract A high prevalence of the BRAFV600E somatic mutation was recently reported in several series of papillary thyroid carcinomas (PTC). This mutation appears to be particularly prevalent in PTC with a predominantly papillary architecture. Another BRAF mutation (K601E) was detected in a follicular adenoma and in some cases of the follicular variant of PTC. The few studies on record provided controversial data on the relationship between the occurrence of BRAF mutations and clinicopathologic parameters such as gender, age and tumour staging. In an attempt to clarify such controversies we decided to enlarge our previous series to 315 tumours or tumour-like lesions diagnosed in 280 patients, including a thorough analysis of several clinicopathologic features. The BRAFV600E mutation was exclusively detected in PTC with a papillary or mixed follicular/papillary architecture both of the conventional type (46%) and of other histotypes, such as microcarcinoma (43%), Warthin-like PTC (75%) and oncocytic variant of PTC (55%). The BRAFK601E mutation was detected in four of the 54 cases of the follicular variant of PTC (7%). The mean age of patients with conventional PTC harbouring BRAFV600E (46.7 years) was significantly higher (P<0.0001) than that of patients with conventional PTC without BRAFV600E (29.5 years). The BRAF (BRAFV600E) mutated PTC did not exhibit signs of higher aggressiveness (size, vascular invasion, extra-thyroid extension and nodal metastasis) and were in fact less often multicentric than PTC without the mutation. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index