KRAS and colorectal carcinoma: Several reports have indicated that K-Ras mutations are negative prognostic markers and portend a poorer outcome in CRC [12] and a meta-analysis of 3439 patients reported that mutation on codon 12 glycine to valine has a statistically significant impact on failure-free survival (FFS) (P = 0.004, HR:1.3) and overall survival (OS) (P = 0.008, HR:1.29) and it is associated with a more aggressive biological behaviour of tumor [13].