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

Stefanius K, Ylitalo L, Tuomisto A, Kuivila R, Kantola T, Sirniö P, Karttunen T J & Mäkinen M J (2011) Histopathology58, 679–692 Frequent mutations of KRAS in addition to BRAF in colorectal serrated adenocarcinoma Aims: To define the occurrence of KRAS and BRAF mutations, microsatellite instability (MSI), and MGMT and hMLH1 methylation and expression in colorectal serrated adenocarcinoma. Methods and results: KRAS codon 12/13 and 59/61 and BRAF V600E mutations, MSI, and MGMT and hMLH1 methylation and expression in 42 serrated adenocarcinomas and 17 serrated adenomas were compared with those in 59 non‐serrated colorectal carcinomas (CRCs) and nine adenomas. KRAS and BRAF mutations were observed in 45% and 33% of serrated adenocarcinomas and in 27% and 0% of non‐serrated CRCs (P