Application of Polygenic Methylation Markers in Postoperative Recurrence Monitoring of Colorectal Cancer

• Patients initially diagnosed with primary colorectal cancer were enrolled for screening, and plasma samples 1-2 days before radical bowel resection were collected for polygene methylation detection.
• The postoperative follow-up was 2 years, and the reexamination included CT/MRI imaging assessment, blood CEA, and dynamic monitoring of plasma ctDNA methylation level. Blood samples were collected for 9 times.
• Results analysis: To explore the application value of ctDNA methylation-MRD detection in the prediction of postoperative tumor recurrence risk after radical resection of colorectal cancer; The correlation between preoperative ctDNA methylation level and prognosis of early colorectal cancer.

Inclusion criteria

• Newly diagnosed patients with primary colorectal cancer confirmed by histopathology (no restriction on histological type);
• Patients diagnosed as stage I-III and feasible for radical bowel surgery;
• Patients diagnosed by stage IV (only colorectal cancer patients with liver metastasis at the time of diagnosis) and feasible radical bowel resection or complete resection of liver metastasis;
• No gender limitation, age ≥18;
• ECOG score ≤1;
• Life expectancy ≥5 years;
• Those who fully understand the study and voluntarily sign the informed consent.

Exclusion criteria

• Blood transfusion was performed during surgery or 2 weeks before surgery;
• complicated with primary malignant tumors of other organs;
• With colonic obstruction, intestinal perforation and other symptoms requiring emergency treatment;
• Colorectal cancer was diagnosed with extrahepatic metastasis;
• Neoadjuvant therapy (such as radiotherapy and chemotherapy) before radical bowel resection;
• Radical bowel resection was performed after endoscopic surgery;
• Concomitant symptoms and/or family history collection suggest hereditary colorectal cancer;
• serious mental illness or drug abuse;
• patients with serious heart, lung and vascular diseases who cannot tolerate surgery;
• pregnant or lactating women;
• Participate in other interventional clinical investigators within 3 months
• Poor compliance, unable to complete the study according to the judgment of the researcher.