It takes about 1-2 years for colon cancer to progress from early to advanced stages. When colon cancer starts to show lesions, tumor cells are confined within the mucosa. With the prolongation of time, it will gradually infiltrate downward, and can reach submucosa, muscular layer, penetrate the muscular layer to reach subplasma, and even invade the plasma membrane or break through the plasma membrane to invade the neighboring normal tissues. There is no lymph node metastasis around the colon, and lymph node metastasis is formed gradually. Because colon cancer is more likely to metastasize through lymph, it will appear in the lymph nodes around the colon at the beginning, and slowly intermediate lymph node metastasis will appear, and finally it will lead to lymph node metastasis in the root of blood vessels.