The BRAF^T1796A mutation associates with patents age but not with radiation ethiology of human papillary thyroid cancer

Abstract

BRAF^T1796A transversion has been shown to be a prevalent event in human papillary thyroid carcinomas (PTCs). In this study the mutation prevalence was examined in radiation-associated PTCs. DNA from the post-Chernobyl (age at exposure below 18 years old) and sporadic PTCs was analyzed by direct sequencing and mutation allele-specific PCR. In the whole radiation-associated PTC group, BRAF^T1796A was found in 17/98 (17.3%) cases with no overall statistical difference from sporadic cases (14/53, 26.4%). However, when radiation-associated series was subdivided in the pediatric (age below 18 years old at diagnosis) and adult cases (age over 18 years old at diagnosis), it was found that in the younger patients the mutational frequency was significantly lower than that in the elder ones, 4/49 (8.2%) versus 13/49 (26.5%), p=0.03. Thus, the BRAF^T1796A mutational rate in PTCs does not associate with radiation history of patients but rather increases with individuals age.