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Meta-Analysis
Copyright: ©Author(s) 2026. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial (CC BY-NC 4.0) license. No commercial re-use. See permissions. Published by Baishideng Publishing Group Inc.
World J Clin Oncol. May 24, 2026; 17(5): 118670
Published online May 24, 2026. doi: 10.5306/wjco.v17.i5.118670
Impact of surgery for colorectal cancer liver metastasis: Systematic review and meta-analysis
Fausto Petrelli, Sara Cherri, Antonio Ghidini, Mauro Rossitto, Roberta Bukovec, Luisa Roncari, Lorenzo Dottorini, Marcella Arru, Michela Libertini, Alberto Zaniboni
Fausto Petrelli, Medical Oncology Unit, ASST Bergamo Ovest, Treviglio, Bergamo 24047, Italy
Sara Cherri, Michela Libertini, Alberto Zaniboni, Department of Oncology, Fondazione Poliambulanza, Brescia 25124, Italy
Antonio Ghidini, Roberta Bukovec, Luisa Roncari, Department of Oncology, Casa di Cura Igea, Milano 20129, Italy
Mauro Rossitto, Lorenzo Dottorini, Marcella Arru, Department of Oncology, ASST Bergamo Ovest, Treviglio, Bergamo 24047, Lombardy, Italy
Author contributions: Petrelli F, Cherri S, Ghidini A, Bukovec R, Rossitto M, Roncari L, Libertini M, and Zaniboni A contributed to the design and implementation of the research; Petrelli F to the analysis of the results and to the writing of the manuscript; Arru M and Dottorini L supervised the project.
AI contribution statement: We confirm that all scientific content, analysis, and conclusions are the result of the authors’ independent work. Language editing tools were used only for minor language refinement. No images included in the manuscript were generated by AI.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Corresponding author: Sara Cherri, MD, Department of Oncology, Fondazione Poliambulanza, Via Bissolati 57, Brescia 25124, Italy. sara.m.cherri@gmail.com
Received: January 8, 2026
Revised: February 6, 2026
Accepted: March 18, 2026
Published online: May 24, 2026
Processing time: 132 Days and 19.1 Hours
Abstract
BACKGROUND

Colorectal cancer is a major public health issue, with liver metastasis marking a critical and prognostically significant pathway for disease progression. This meta-analysis evaluated the association between surgical intervention for colorectal liver metastases and survival outcomes to inform multidisciplinary treatment decisions. We performed a thorough search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from their inception until February 1, 2024. Included studies enrolled at least 20 patients and compared overall survival (OS) and/or progression-free survival (PFS) between surgical and non-surgical management, reporting hazard ratios (HRs) with 95% confidence intervals (CIs) or providing sufficient time-to-event data to estimate HRs. We pooled HRs using a random-effects model. Of 2935 records, 67 studies involving 368380 patients were included, most of which were retrospective cohorts. Surgical resection was associated with improved OS (pooled HR = 0.38, 95%CI: 0.34-0.43) and PFS (pooled HR = 0.46, 95%CI: 0.31-0.66). Subgroup analyses indicated a consistent direction of association across several study-level characteristics. Given substantial heterogeneity and the predominance of observational data, residual confounding by indication cannot be excluded; therefore, pooled estimates should be interpreted as associations in selected patients. Prospective studies incorporating contemporary systemic therapy and tumor biology are warranted to refine patient selection and treatment sequencing.

AIM

To provide an aggregate prognostic value for surgery for liver metastases, incorporating HRs with 95%CIs from multivariate or univariate analyses available in the included studies.

METHODS

Sensitivity analysis was conducted even with meta-regression based on participant ethnicity (Asian vs non-Asian), number of patients, median follow-up, publication year (pre-2015 vs 2015-2024), paper quality (high vs low), and study design (retrospective vs prospective). Heterogeneity among studies was assessed using Cochran’s Q test, with P < 0.05 or I2 > 50% indicating significant heterogeneity, in which case a random-effects model (Der Simonian-Laird method) was applied. Otherwise, a fixed effects model was used. HR < 1 indicated improved survival in patients undergoing resection of liver metastases. Data were analyzed using the Review Manager (RevMan) software, version 5.4, The Cochrane Collaboration, 2020. Publication bias and small-study effects were assessed by visual inspection of funnel plots, Egger’s regression test, and rank-correlation testing; Duval and Tweedie’s trim-and-fill method was applied as a sensitivity analysis. Clinically, the attenuation of the pooled effect estimate after trim-and-fill adjustment suggests that the magnitude of survival benefit associated with surgery may be partially overestimated due to small-study effects or selective publication. However, the direction of the association remained consistent, supporting an association between surgical resection and improved survival in carefully selected patients.

RESULTS

Of the 2935 records identified, 67 studies with data from 368380 patients (ranging from 21 to 72376) were included in the meta-analysis. Most of the included studies (55 out of 67) were retrospective series, whereas 12 out of 67 were prospective (either clinical trials or prospective cohorts). The treatment strategies in the included studies consisted of upfront surgery followed by adjuvant therapy or preceded by neoadjuvant or conversion therapy (including three studies in which patients received hepatic artery infusion chemotherapy). Data regarding systemic therapies were unavailable for 17 studies. Data on the overall resection rate were available for 62 of the 67 studies. Resection rates ranged from 8% to 100% (median, 45%), whereas R0 resections ranged from 2% to 87% (median, 14%). The median follow-up period ranged from 4 months to 120 months (median, 37 months); however, it was not available in 42% of the papers.

CONCLUSION

Among the evaluable studies, the publication quality was classified as low (36%), moderate (46%), or high (18%). The association between surgery for colorectal liver metastases and survival outcomes is described in subsequent sections. Outcomes were analyzed using multivariate analysis in 90% of the cases.

Keywords: Colorectal cancer; Liver metastases; Surgery; Survival; Meta-analysis

Core Tip: The survival benefit of surgical resection for colorectal liver metastases has been debated, particularly in heterogeneous clinical settings. This systematic review and meta-analysis synthesizes available evidence and shows that surgery is associated with improved overall and progression-free survival compared with non-surgical approaches, although heterogeneity is substantial and most data are observational. Future studies should focus on defining predictive factors for benefit and identifying patient subgroups in whom alternative strategies may be more appropriate.

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