After surgery for stage I rectal cancer, the 5-year survival rate of patients can be more than 90%. The 5-year survival rate after surgery for stage II and III rectal cancer is usually 70% to 80%, and the 5-year survival rate for patients with advanced rectal cancer may be 10% to 20%. Stage I rectal cancer only invades to the submucosa or superficial muscle layer, and there is no lymph node or metastasis to distant organs such as liver and lungs. The primary lesion can be completely removed through surgery, and the survival rate of patients can reach more than 90% in 5 years. Stage II and III rectal cancer may have deeper invasion and lymph node metastasis may occur. If the surgery is not complete and the degree of malignancy is high, the rectal cancer may recur and metastasize. Patients generally have a 5-year survival rate of 70% to 80%. If it is advanced rectal cancer and has metastasized to distant organs such as liver and lung. With surgical resection and adjuvant treatment such as chemotherapy and radiotherapy, the 5-year survival rate of patients may be 10% to 20%. Patients who have spread or metastasized to the whole body and cannot undergo surgery may have a survival rate of less than 10%. Therefore, the survival time after surgery for rectal cancer needs to be decided according to the staging and postoperative conditions, and patients should cooperate with doctors for active treatment to prolong the survival period.