When the relationship between KRAS status and initial metastatic sites at the time of diagnosis of stage IV disease or recurrence (in the cases of initial stages I to III) was analyzed (N = 143), patients with MT KRAS had a higher rate of initial lung metastasis (45.3%) than patients with WT KRAS (22.1%; P = 0.003). This evidence concerns the gene KRAS and metastasis.