KRAS and BRAF mutations in Serbian patients with colorectal cancer

Summary Purpose: Mutations of KRASand BRAF genes repre-sent molecular biomarkers of response to targeted therapy in patients with metastatic colorectal cancer (mCRC). Since these mutations have been shown to exert different biologi-cal effects and impacts on patients’ outcome, there is a need to determine reliably the frequency and types of KRASmu-tations for diagnostic and individual therapeutic purposes. Despite having a wild type (wt) KRAS, some patients fail to respond to treatment. BRAF V600Emutation is an addition-al molecular determinant of response to the same therapy. In this study we described the KRASand the BRAF V600Emu-tation spectra and frequencies in a group of SerbianmCRC specimens. Methods: KRASmutations were determined with DxS TheraScreen ® K-RAS Mutation Kit and KRASStripAssay™, and for the BRAF V600Emutation we applied High Resolu-tion Melting (HRM) analysis. Results: KRASmutations were present in 34.7% of 190 analyzed samples. The 7 most frequent mutation types observed were: G12D 43.9%, G12V 21.2%, G12A 10.6%, G12C 7.6%, G12S 4.5%, G12R 1.5%, G13D 10.6%. Among the wt KRASpatients, 17.8% carried the BRAF V600Emu-tation.