KRAS and neoplasm: Fisher’s exact test showed no existence of an association between the mutational status of KRAS (WT or mutated) and the following clinical-histopathological variables: sex, age, tumor location, histological pattern, stage (TNM) and degree of tumor differentiation; because no statistical evidence was observed significant in order to reject the null hypothesis that the mutational state results independent of these variables (p > 0.05).