Early Recurrence of Colorectal Liver Metastasis (Number ≤ 5 and Largest Diameter ≤ 3 cm) after Resection or Thermal Ablation: a Multi-center Study of Patterns, Safety, Survival and Risk Factors.

Objective: To compare early recurrence patterns, safety, survival and investigate the clinical risk factors of early recurrence (ER) after liver resection or thermal ablation (TA) for patients with colorectal liver metastases (CRLM) with number ≤ 5 and largest diameter ≤ 3 cm.

Materials and methods: This retrospective study included patients with CRLM who underwent liver resection or TA between January 2016 and December 2021 at two hospitals in China. The Kaplan-Meier method and log-rank test were used to assess recurrence-free survival (RFS) and overall survival (OS). Risk factors for ER were analysed using univariate and multivariate Cox regression analyses.

Results: 303 patients with 632 liver metastases were enrolled. The most common early recurrence pattern was intrahepatic recurrence (IHR) in resection group and TA group. There was no significant difference in 6-month RFS rate (65.81% vs 66.23%) and median OS (P = 0.10) between two groups. Patients without ER had better OS than those with ER (P < 0.05). The incidence of serious complications (P = 0.013), length of hospitalization (P < 0.01), and albumin-bilirubin (ALBI) score (P = 0.038) in TA group were significantly better than resection group. The diameter of liver metastases (HR: 4.89, 95% CI: 1.16-20.60; P = 0.031) and clinical risk score (CRS) (HR: 1.86, 95% CI: 1.06-3.25; P = 0.029) were independent risk factors for ER.

Conclusion: For CRLM with largest diameter ≤ 3 cm and number ≤ 5, the efficacy of receiving resection or TA is comparable, and the safety of TA is better. TA may be considered as the first-line local treatment option for patients with CRLM.