Surgical Resection Versus Microwave Ablation for Colorectal Liver Oligometastases: A Multicenter Cohort Study of 1027 Patients.

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.