Superficial invasive carcinoma can be early stage, but the specific staging should be judged with the lymph node metastasis and whether distant metastasis occurs. The commonly used clinical staging of malignant tumors is TNM staging, which can be used to guide treatment and judge specific prognosis. T is the primary tumor, which can be interpreted as the degree of infiltration; N is the lymph node metastasis; and M is whether distant metastasis occurs, which can be generally divided into four stages. For example, in colon cancer, stage I, i.e. early stage, can be the tumor growing into the submucosal layer, but not infiltrating the intrinsic muscle layer; there is no lymph node and distant metastasis; stage IV, i.e. late stage, can be the occurrence of distant metastasis irrespective of the development of the tumor and the degree of lymph node metastasis. Therefore, the judgment of the specific stage can not be based only on the degree of cancer infiltration.