Independent Risk Factors Analysis and Model Construction For Recurrence After Radiofrequency/Microwave Ablation of Colorectal Cancer With Liver Metastases: a Retrospective, Multicenter Trial

Inclusion Criteria: 1. Age：older than 18 years； 2. Patients with a single tumor diameter ≤5cm, no more than 3 tumor nodules, and the largest tumor diameter ≤3cm； 3. Absence of vessel, bile duct and adjacent organ invasion and distant metastasis; 4. The primary tumor of colorectal cancer has been resected, the liver metastases cannot be resected or the patient is unwilling to undergo surgery (clinical or pathological confirmation); 5. Normal coagulation status and liver function child-pugh A or B; 6. Liver metastases have not received other antitumor therapy after radiofrequency/microwave therapy (before disease progression); 7. Routine laboratory tests were performed before the first RF/microwave treatment; 8. Follow up for more than 12 months; 9. Obtained free informed consent. Exclusion Criteria: 1. Large tumor, or diffuse intrahepatic metastasis; 2. Accompanied by vascular tumor thrombus or invasion of adjacent organs; 3. The primary tumor of colorectal cancer has not been resected, with extrahepatic metastasis; 4. Uncorrectable coagulation dysfunction and severe blood abnormalities, those with severe bleeding tendency; 5. Intractable massive ascites, cachexia; 6. Active infection, especially inflammation of the biliary system; 7. Severe liver, kidney, heart, lung, brain and other major organ failure; 8. Patients with impaired consciousness or unable to cooperate with treatment; 9. Missing follow-up data.