common kras and braf mutations in colorectal cancer patients

background kras and braf gene mutations are considered as key events in carcinogenesis progression of colorectal cancer. given the importance of these gene mutations evaluations, especially in metastatic patients, in terms of determination of therapeutic strategies, we studied the prevalence of kras and braf mutations in tabriz city.   materials and methods deoxyribonucleic acid (dna) extracted from fresh tumor and normal tissues of 30 primary crc patients. direct sequencing method, was the method for determining the mutation points of kras exon 2   and braf exon 15 genes. after mutation analysis, the clinical and pathological associations of mutant genes were assessed.   results the prevalence of kras gene mutation was 20 %( 6 out of 30 cases) in this study, and none of patients had the mutant braf gene. the odds ratio of the kras gene mutation in high grade crcs was 2.1(95% ci: 1.34 to 3.29). the same ratio for metastasis was 1.1(95% ci: 0.93 to 1.25). there was no significant relationship between the mutation and clinical and pathological aspects of the disease.   conclusion the high occurrence of early onset of colorectal cancer in iran demands more attention to screening and prevention programs in the younger age group in the country. however further genetic studies are needed at the molecular level and large population in different geographical areas.