Application of FIT-DNA Detection in Following Colorectal Cancer Resection-Implications for Surveillance

Inclusion Criteria: * 1). The pathological diagnosis was colorectal adenocarcinoma； 2). Age: 18 to 80 years old,allgenders； 3). Radical surgery for CRC is required； 4). No preoperative antitumor therapy (including chemotherapy, radiation therapy, targeted therapy, and immunotherapy)； 5). Preoperative examination revealed no distant metastasis； 6). There were no severe hemorrhoids or other known conditions that can cause gastrointestinal bleeding before surgery； 7). The clinical treatment data were complete； Exclusion Criteria: * 1). With a history of digestive tract tumors other than CRC； 2). Previous colorectal surgery； 3). Patients requiring a fistula； 4). With complete intestinal obstruction or perforation； 5). Women who are pregnant or breastfeeding； 6). Patients with metastases found in other sites during surgery that cannot be removed radically； 7). Patients unwilling or unable to sign an informed consent form； 8). A strict vegetarian； 9). Patients who are unwilling to follow up according to the protocol or have poor follow-up compliance； 10). Any conditions that the study physician deemed inappropriate for inclusion。 Exit or terminate criteria： 1. . Follow-up information for the patients was not available 2. . Distant metastasis was diagnosed after surgery 3. . Subjects died before the end of follow-up.