At present, TNM staging is generally used in China to stage colon cancer. t stands for primary tumor, n stands for lymph node metastasis, and m stands for distant metastasis. 1. 1. T: T stands for primary tumor; Tx refers to the inability to estimate the primary tumor; T0 for no evidence of tumor; Tis for carcinoma in situ; T1 for tumor invasion of submucosal layer; T2 for intrinsic muscular layer involvement; T3 for invasion of submucosal layer; T4 for penetration of plasma membrane layer and direct invasion of other tissues. 2.N: N refers to the inability to estimate lymph nodes; no lymph node metastasis is N0; 1 to 3 regional lymph node metastasis is N1; 4 or more regional lymph node metastasis is N2. 3. M: M refers to the inability to estimate distant metastasis; no distant metastasis is M0; with distant metastasis is M1. The causes of colon cancer are related to environmental pollution, food and carcinogenic substances. Some patients may have changes in defecation habit and fecal character at an early stage, which should be noticed. The principle of treatment is comprehensive treatment mainly based on surgery. The prognosis is better if patients are helped to adjust the smooth emotional psychology and dietary structure. If you have mucus blood stool, chronic diarrhea, chronic constipation and other uncomfortable symptoms, please go to the regular hospital in time to be examined by a professional physician for you, diagnosis and treatment.