Frequent mutations of KRAS in addition to BRAF in colorectal serrated adenocarcinoma

Abstract

A high combined mutation rate (79-82%) of KRAS and BRAF in serrated adenomas and adenocarcinomas indicates that mitogen-activated protein kinase activation is a crucial part of the serrated pathway. BRAF mutations are specific for serrated adenocarcinoma and identify a subset of serrated adenocarcinomas with gene methylation and a tendency for MSI-H. A high frequency of KRAS mutations in serrated adenocarcinomas suggests that a significant proportion of KRAS-mutated CRCs originate from serrated precursors, thus challenging the traditional model of Vogelstein.