Comparative outcomes of combined thermal ablation and liver resection versus liver resection alone for multiple colorectal liver metastases: a systematic review and meta-analysis

Abstract

Background: The treatment of colorectal liver metastases (CRLM) continues to pose a significant clinical challenge, with surgical resection remaining the gold standard. However, the efficacy of combining thermal ablation (TA) with liver resection (LR) compared to LR alone in managing multifocal CRLM remains a topic of debate. This meta-analysis aims to compare the outcomes of combining TA and LR with LR alone in patients with multifocal CRLM.

Methods: A comprehensive literature search was conducted across PubMed, EMBASE, Cochrane Library, and Web of Science up to December 2024. Studies that compared the combination of TA and LR with LR alone in patients with CRLM and reported at least 1-, 2-, or 3-year overall survival (OS) and/or disease-free survival (DFS) were included. Data were extracted and analyzed using random-effects or fixed-effects models, depending on the degree of heterogeneity. Sensitivity analysis and assessment of publication bias were performed to ensure the robustness of the findings.

Results: Six retrospective cohort studies involving 3084 patients (1286 in the TA+LR group and 1798 in the LR group) were included. No significant differences were found in 1-, 2-, and 3-year OS between the TA+LR and LR groups. However, the TA+LR group exhibited worse DFS. Subgroup analysis revealed a more pronounced decline in DFS in non-European TA+LR cohorts compared to LR cohorts, potentially reflecting regional differences. Additionally, DFS was significantly lower in the radiofrequency ablation (RFA) subgroup compared to the microwave ablation (MWA) subgroup. Complication rates were comparable between the two groups. Sensitivity analysis confirmed the stability of the results, and no significant publication bias was detected.

Conclusion: Combining thermal ablation with liver resection is a feasible liver-sparing approach for treating extensive CRLM, applicable through both laparoscopic and open surgical techniques. Combined resection and ablation should be considered as an alternative to resection alone for patients with multiple metastases.

Systematic review registration: PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42024629343.

Keywords: colorectal cancer; liver metastases; liver resection; meta-analysis; thermal ablation.

Figure 1

The flowchart describing the selection of the literature.

Figure 2

Forest plots comparing overall survival rates between TA+LR and LR groups. (A) Pooled analysis of the 1-year overall survival rate. (B) Pooled analysis of the 2-year overall survival rate. (C) Pooled analysis of the 3-year overall survival rate. OR, Odds ratio; CI, Confidence interval.

Figure 3

Forest plots comparing disease-free survival rates between TA+LR and LR groups. (A) Pooled analysis of the 1-year disease-free survival rate. (B) Pooled analysis of the 2-year disease-free survival rate. (C) Pooled analysis of the 3-year disease-free survival rate. OR, Odds ratio; CI, Confidence interval.

Figure 4

Subgroup analyses based on geographic region (European vs. Non-European studies). (A) Subgroup analysis comparing the 1-year overall survival rate. (B) Subgroup analysis comparing the 2-year overall survival rate. (C) Subgroup analysis comparing the 3-year overall survival rate. (D) Subgroup analysis comparing the 1-year disease-free survival rate. (E) Subgroup analysis comparing the 2-year disease-free survival rate. (F) Subgroup analysis comparing the 3-year disease-free survival rate. OR, Odds ratio; CI, Confidence interval.

Figure 5

Subgroup analyses based on ablation modality (Microwave Ablation [MWA] vs. Radiofrequency Ablation [RFA] vs. Thermal Ablation [TA]). (A) Subgroup analysis of the 1-year overall survival rate. (B) Subgroup analysis of the 2-year overall survival rate. (C) Subgroup analysis of the 3-year overall survival rate. (D) Subgroup analysis of the 1-year disease-free survival rate. (E) Subgroup analysis of the 2-year disease-free survival rate. (F) Subgroup analysis of the 3-year disease-free survival rate. OR, Odds ratio; CI, Confidence interval.

Figure 6

Comparative analysis of postoperative complications in TA+LR and LR groups. This figure presents a pooled analysis comparing the incidence of postoperative complications between patients in the TA+LR group and those in the LR group. A fixed effects model was applied for the analysis. Each horizontal line indicates the study-specific hazard ratio and its corresponding 95% confidence interval. The size of the squares represents the relative weight of each study in the analysis, while the diamond shape denotes the overall pooled odds ratio and its 95% confidence interval. OR, Odds ratio; CI, Confidence interval.

Figure 7

Sensitivity analyses of the survival rate comparisons between patients in the TA+LR and LR groups.

Figure 8

Funnel plot describing the comparative analysis of survival rates between patients in the TA+LR and LR groups.