Management of patients with recurrence of colorectal cancer Most of the local recurrence of colorectal cancer after surgery occurs six months to two years after surgery. Most of the patients first show dynamic elevation of serum CEA during postoperative follow-up, followed by symptoms of abdominal mass, abdominal pain, incomplete bowel obstruction and gastrointestinal bleeding. Colonoscopy, colon gas-barium double imaging, abdominal CT, and positron computed tomography (PET) scan confirm the recurrence of anastomosis or intra-abdominal cavity, with or without metastasis to other organs. Nodal recurrence refers to isolated node-like recurrence in the abdominal cavity, which is caused by insufficient resection of colonic mesentery in the first operation or insufficient clearance of metastatic lymph nodes in the abdominal cavity. 2. Anastomotic recurrence refers to tumor recurrence located in the anastomosis and its nearby intestinal wall, which can grow into the lumen or outside the lumen with or without infiltration of surrounding tissues. It is mostly caused by insufficient length of resection of intestinal canal at both ends of surgery and residual cancer cells at the cutting edge, or cancer cells in the intestinal cavity are shed by preoperative enema and intraoperative extrusion and planted in the anastomosis or its nearby mucosa. Intra-peritoneal recurrence refers to the recurrence of tumor on the plasma membrane surface of peritoneal cavity, which is often multiple or diffuse, caused by the primary tumor having penetrated the plasma membrane or cancer cells dispersed in the peritoneal cavity or pelvic cavity during surgery, and the diffuse spread of peritoneal cavity is often combined with cancerous ascites. 4.Local recurrence combined with cancer metastasis in liver, lung and other tissues. The purpose of re-operation for recurrence of colon cancer after surgery: First, to combine with comprehensive treatment measures to achieve the purpose of radical cure through re-operation; second, to relieve the symptoms caused by tumor recurrence, prolong the survival time of patients, reduce pain and improve the quality of life. More than one-third of patients who undergo radical surgery for stage II, III and II colon cancer have recurrence, and only 10%-20% of them can undergo radical resection again. Commonly used surgical procedures include radical resection of recurrent tumors, palliative resection, short-circuit surgery or proximal obstruction stoma. Whether a recurrent tumor can be radically resected and the prognosis after various surgeries depend on various factors, including the site of recurrence, the type of recurrence, the time of recurrence, and whether it is accompanied by metastases from other organs. The rate of secondary surgical radical resection is significantly higher in asymptomatic patients than in symptomatic patients at the time of tumor recurrence. The 5-year survival rate of radical resection is 19%-35%, while the 5-year survival rate of non-surgical or palliative surgery after recurrence is less than 5%. Complete resection of recurrent colon cancer can significantly prolong the survival of patients. Patients who can only undergo palliative resection due to cancer invasion of major blood vessels, peritoneum and extensive metastasis in the incision have a short postoperative survival, but most patients have significantly reduced pain and improved the quality of survival. In terms of the time of recurrence and surgical resection rate and prognosis, the earlier the time of recurrence of tumor indicates the high malignancy of the primary tumor, the lower the possibility of radical resection and the poor prognosis. The surgical resection rate and postoperative survival of different recurrent tumor types also vary greatly. Combined with chemoradiotherapy, the 5-year survival rate of nodal recurrence after reoperation can be 40-50%, anastomotic recurrence is about 30%, intra-abdominal and pelvic recurrence is 15%, while the prognosis of mixed recurrence with metastasis to liver, lung and bone is poor and there is no 5-year survivor. If the general condition is good, the examination indicates that there is no distant metastasis in liver and lung, and the CT of abdominal cavity indicates that the tumor is solitary and isolated, and there is still a certain gap with the inferior vena cava, abdominal aorta, pancreas, duodenum and other retroperitoneal organs, even if there are no obvious clinical symptoms, we should try to resect it again. For local recurrence with obvious clinical symptoms, such as intestinal obstruction, abdominal pain or persistent gastrointestinal bleeding, the focus of surgery is to relieve the patient’s pain and prolong survival. If the systemic and abdominal conditions allow, surgery should be actively performed to strive for radical or palliative resection under the premise of relieving symptoms, and for those who cannot be resected, the obstruction should be relieved by enterostomy or short-circuit surgery. The tumor itself should be carefully evaluated for resectability before surgery, and operated carefully during surgery to avoid damage to surrounding organs and reduce complications beyond. The patient’s general condition should be adjusted before surgery to correct anemia, hypoproteinemia and water-electrolyte imbalance, and for those with large tumors that are expected to be difficult to be resected, chemotherapy or radiotherapy can be administered first, and surgery can be performed after the tumor becomes smaller.