Among the patients who come to the Bowel Cancer Integration Clinic, there are recurrent bowel cancer patients from all over the country and even overseas who have undergone surgery. The question that we often hear is: Why has the cancer recurred now? Is it because the doctor did not open the knife properly? In response to such questions, we will generally give answers from the following aspects. I. Bowel cancer has a high recurrence and metastasis rate Malignant tumors actually have a certain probability of recurrence and metastasis, even for early stage cancer, but this feature is more obvious in bowel cancer. Statistics show that about 900,000 people worldwide suffer from bowel cancer every year, and nearly 75% of them are treated with surgery, but even after radical surgery, half of them still have recurrence and metastasis, of which nearly 90% occur within 3 years after surgery, and the probability of occurrence after 5 years after surgery is greatly reduced. That is why we recommend patients who underwent radical surgery for intestinal cancer to have regular postoperative review, with tumor markers (CEA, CA199, etc.) reviewed every three months within 1 year after surgery, every six months from 2 to 3 years, and every year after 3 years; chest X-ray, CT, MRI, etc. reviewed every year from 1-3 years, and the examination interval can be extended appropriately after 3 years; colonoscopy can be After 3 years, the interval between examinations can be extended; colonoscopy can be done once in 1 and 3 years after surgery, and once every 3 years afterwards. There are many factors related to recurrence and metastasis of intestinal cancer, and the common reasons include: 1. Surgery-related factors: failure to improve necessary preoperative examinations, resulting in missing metastases, or the sensitivity of current imaging examinations is limited, resulting in failure to diagnose tiny metastases that already exist; inaccurate preoperative assessment and insufficient surgical scope, resulting in surgical resection without cutting the bottom; irregular surgical operation, resulting in failure to achieve radical resection (R0). Although the surgery was performed in accordance with the routine operation, the tumor progressed locally, and the enlarged or combined organ resection was not performed, or the metastatic organs such as ovaries were missed. Surgery can only remove the lesions visible to the naked eye. For the tiny lesions not visible to the naked eye and the tumor cells entering the bloodstream, further treatment is usually by chemotherapy/radiotherapy/targeted drugs; even for some early and middle stage patients, due to the existence of some risk factors, doctors will also recommend the follow-up treatment. Therefore, there is a higher risk of recurrence and metastasis for patients who do not follow the medical advice for postoperative radiotherapy. Of course, even if the standardized perioperative adjuvant radiotherapy is carried out, there may be recurrence due to poor sensitivity of radiotherapy. What are the manifestations of recurrence and metastasis? 1.Early and mid-term symptoms: early stage is asymptomatic, after development, there can be elevated serum tumor markers, and after continued progress, there can be abdominal pain; abdominal mass; change of stool habit; blood in stool, etc. 2.Stage symptoms: intestinal obstruction; cachexia; urethro-rectal fistula will appear after invasion of urinary system, and rectovaginal fistula may appear in women. Therefore, a strict follow-up after surgery is very important, especially for high-risk patients. Early detection of some traces such as elevated CEA, CA199 and other indicators in blood can lead to early detection of recurrent lesions by some more sensitive techniques such as PET/CT and early intervention for treatment. Compared with other cancers such as gastric cancer, hepatobiliary and pancreatic tumors, and gynecological tumors, recurrent bowel cancer has better efficacy and prognosis and does not mean end stage, so it should not be given up lightly. For example, for resectable lesions of metastatic liver and local recurrent lesions of abdominopelvic cavity, if complete resection is achieved, there is still a considerable five-year survival rate of 40-50%. Fourth, recurrent metastases should be done 1, surgical treatment: including local expanded resection again, combined organ resection, partial sacral resection, palliative surgery, etc. According to the preoperative assessment, the corresponding surgical plan will be taken in combination with the site of recurrent metastasis and the general condition of the whole body. 2. Combined treatment: including various types of treatment, such as perioperative radiotherapy, peritoneal warm perfusion chemotherapy, interventional therapy, radiofrequency therapy, HIFU knife therapy, etc. According to the specific situation of the patient, the best comprehensive treatment plan is adopted. Through multidisciplinary discussions, individualized comprehensive treatment plans are formulated for patients, taking into account survival and quality of life, in order to obtain the best efficacy. In the treatment of recurrent bowel cancer, the role and significance of multidisciplinary, also known as MDT team, is even more significant, because the situation often encountered is that there are no clear so-called international guidelines to follow, and it is necessary to make individualized comprehensive treatment plans based on the existing expert consensus and through the analysis and discussion of MDT team. Combined with clinical experience, individualized treatment strategies are made.