As a result, it was observed that the frequency of mutations in the KRAS, NRAS and PIK3CA genes were similar in metastatic tumors versus primary tumors; TP53 mutations were more frequent in metastatic versus primary tumors (53 versus 30%, respectively), while BRAF mutations were significantly less frequent (1.9 versus 7.7%). This evidence concerns the gene KRAS and metastatic neoplasm.