MRD Test in Common Risk Stage II Colorectal Cancer

This observation part is about the patients with general risk stage II colorectal cancer who have received R0 resection after screening by nanofiltration criteria. Twenty milliliters of venous blood samples were reserved before surgery, and tumor tissue samples were reserved within 30 minutes in vitro during surgery. After the pathological diagnosis of the patients after surgery, they began to be enrolled. To observe the sensitivity of MRD detection in preoperative diagnosis of patients with general risk stage II colorectal cancer, and to study its positive rate one month and three months after operation.