Sigmoid colon adenocarcinoma T4M1 means sigmoid colon cancer, the pathological type is adenocarcinoma, and T4M1 is the TNM staging of the tumor, which indicates that the tumor has penetrated the dirty peritoneum and accompanied by distant metastasis, suggesting that the tumor has developed to the middle or late stage. TNM staging is a commonly used clinical staging method for colorectal cancer, with T indicating the depth of infiltration of the primary tumor, N indicating the number of local lymph node metastasis, and M indicating the presence of distant metastasis, which basically reflects the prognosis. Sigmoid colon adenocarcinoma is mainly tubular adenocarcinoma, papillary adenocarcinoma, mucinous adenocarcinoma and so on. Tubular adenocarcinoma can be divided into highly differentiated, moderately differentiated, and poorly differentiated according to the degree of differentiation, and the degree of malignancy gradually increases; mucinous adenocarcinoma is more malignant; and indolent cell carcinoma has the highest degree of malignancy, and has the worst therapeutic prognosis. Although the prognosis can basically be reflected according to TNM staging, the prognosis of aggressive surgery for radical resection is obviously better than that of patients with palliative treatment, and there are some differences in the prognosis due to the differences in geographical medical level. Therefore, if the diagnosis has been confirmed, the patient should be treated aggressively as early as possible and strive for the opportunity of surgery in order to obtain the best prognosis.