KRAS and neoplasm: The results demonstrated that KRAS mutation was highly associated with non-adenocarcinoma (45.21% vs. 32.54%, P = 0.003), right colon (43.04% vs. 32.47%, P = 0.008), well and moderately differentiated tumor (38.0% vs. 22.12%, P = 0.002), and positive CA 19-9 (45.10% vs. 33.46%, P = 0.011) but not associated with CEA (40.13% vs. 32.70%, P = 0.054).