The occurrence of liver metastasis after curative surgery for resectable colorectal cancer is an important cause of death for patients. Accurately identifying high-risk patients for metastasis and intervening in them has important clinical significance. The pathological examination of surgical specimens failed to fully utilize valuable specimen information and accurately predict liver metastasis; The biomarkers secreted by tumors are metabolized in the liver through the portal vein, especially the particles such as extracellular vesicles secreted by tumors, which are ultimately diluted in peripheral blood and cannot be effectively detected. Our research group extracted an average of 11.25ml of blood (named blood derived from portal vein branch specimens, sdBlood for short) from 8 colorectal cancer radical surgery specimens. Compared with peripheral blood, protein mass spectrometry analysis revealed a significant increase in exosome proteins such as peroxidized redox protein 1 (PRDX1), which are highly correlated with metastasis. This project innovatively uses sdBlood, which has been overlooked by routine pathological examination, to detect the exosomal protein PRDX1 in sdBlood, which is significantly higher than the peripheral blood concentration. A prospective cohort study was established, including 252 patients with pathologically confirmed colorectal cancer after radical surgery. The incidence and time of liver metastasis were followed up and observed. Cox regression statistical analysis was used to determine the correlation between this marker and metastasis and determine its critical value, providing a basis for clinical diagnosis and treatment.

Inclusion Criteria:

• Age between 19-80 years old, gender not limited;

  • Can comply with the requirements of the research visit plan and other protocols;

    • Voluntarily participate and sign an informed consent form; ④ Diagnosed with colon adenocarcinoma through pathological examination; ⑤ Patients who have completed colorectal radical surgery.

Exclusion Criteria:

• Patients who cannot complete radical surgery for colorectal cancer;

  • Patients with liver diseases (chronic hepatitis B, hepatitis C, severe fatty liver, cirrhosis);

    • Patients who require combined organ resection;

      • Combine patients with other malignant tumors or blood or immune system diseases; ⑤ Prior to tumor resection, any anti-tumor treatment, including radiotherapy, chemotherapy, and molecular targeted therapy, has been performed; ⑥ After surgery, it was found that the mesenteric vein branch of the specimen could not obtain blood due to severe infiltration or other reasons.

        • Patients with severe postoperative complications leading to delayed treatment (Clavien-Dindo grade III or above).

Local resectable colorectal cancer patients aged 19-80 years who have not undergone preoperative radiotherapy or chemotherapy and have no distant metastasis.