Abstract
BACKGROUND: The choice between surgical resection (SR) and microwave ablation (MWA) as first-line treatments that prolong survival duration for colorectal liver oligometastases (CRLOM) remains controversial. OBJECTIVE: This study aimed to compare survival outcomes, therapeutic parameters, and safety between SR and MWA in patients with CRLOM. METHODS: From January 2012 to December 2022, we identified 1027 eligible patients with CRLOM who underwent either SR (n = 464) or MWA (n = 563) as hepatic local-region treatment. The cumulative 1-, 3-, 5-, and 8-year overall survival (OS) and progression-free survival (PFS) rates between the two modalities were compared using the Kaplan-Meier method with the log-rank test. The propensity score matching (PSM) method was used to improve the selective bias. Univariate and multivariate analyses of clinicopathological variables were conducted to identify risk factors affecting long-term survival. RESULTS: After PSM, all baseline variables were balanced between the SR (n = 393) and MWA groups (n = 393). After a median follow-up of 39.8 months, no significant differences in the long-term survival outcomes were observed between the two groups (median OS time, MWA: 70.6 months vs. SR: 83.2 months; P = 0.124; median PFS time, MWA: 18.5 months vs. SR: 22.3 months; P = 0.680). PSM-adjusted analyses revealed similar results. The presence of 3-5 intrahepatic nodules (hazards ratio [HR] 1.65; 95% CI 1.31-2.06; P < 0.001) and SR (HR 1.28; 95% CI 1.11-1.69; P = 0.028) were independent prognostic risk factors for OS. A significant interaction effect of therapeutic modality and age, pathological differentiation, diameter, and number was observed (P = 0.039, 0.004, 0.031, and 0.032). CONCLUSIONS: MWA offers comparable long-term survival benefits to SR for patients with CRLOM.