The Mutation Profiles of KRAS and BRAF Genes in a Romanian Colorectal Cancer Cohort

Abstract

Colorectal cancer (CRC) is one of most commonly diagnosed malignancies and management of CRC differs in according with patient�s characteristics, tumor type, differentiation, metastatic extension and KRAS/BRAF mutations. Based on this knowledge, we examined the relationship between KRAS/BRAF mutations in paraffin-embedded tumor specimens and some clinicopathological features at CRC in order to provide reliable results to the oncologists and so to contribute to the best care provided to the patients. A 56 of colorectal cancer samples were analyzed for the KRAS and BRAF mutational status using StripAssay method from ViennaLab, Austria. Assays for identification of KRAS/BRAF mutations were based on polymerase chain reaction (PCR) and reverse-hybridization. KRAS mutations were present in 50% (28 patients) of all analyzed CRC and were located in codons 12, 13 and 61. The most frequent types of mutations were substitution of glycine to valine in codon 12 (c.35G]T; 9/28), followed by glycine to aspartate on codon 13 (c.38G]A; 5/28). BRAF mutations were detected at 9 patients (16%) and in all cases Val600Glu mutation has been observed. In one case we reported a concomitant KRAS/BRAF mutation. According with current data, KRAS and BRAF mutations are associated with a poor patient prognosis in CRC, but KRAS mutation in codon 13 and BRAF appear to have a higher oncogenic potential.