Distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer.

Targeted therapies have an increasing importance in digestive oncology. To our knowledge, we are the first to report the distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer (CRC) in order to introduce targeted therapy in the arsenal of therapeutic modalities for management of this cancer in Morocco. In this study, 92 samples obtained from patients with CRC were tested for the presence of the nine most common mutations in the KRAS gene and BRAF gene. Among the tested patients, 76.09% of patients had wt-KRAS genotype and 23.91% were KRAS mutants and the majority of mutations would result in an amino acid substitution of glycine by aspartic acid (68.2%) The predominant mutations are G>A transitions and G>T transversions. Around 5% (5.43%) of the tested patients bore the V600E mutation in BRAF gene. Only one patient showing to have the V600E mutation in BRAF was also mutated-KRAS. Summing up the results about the KRAS and the BRAF mutation carriers from our study, the portion of potentially non responsive patients for the anti-EGFR treatment is 28.26%.