Surgical Resection of Metachronous Liver Metastases in Non-colorectal Non-neuroendocrine Gastrointestinal Cancers: Systematic Review and Meta-analysis.

BACKGROUND/AIM: Hepatic resection is the standard of care for colorectal and neuroendocrine liver metastases, but its role for metachronous liver metastases from non-colorectal non-neuroendocrine (NCRNNE) gastrointestinal cancers remains controversial, with limited evidence and no established guidelines. The aim of this study was to evaluate whether surgical treatment of metachronous liver metastases is associated with improved overall survival compared with non-surgical management in patients with primary non-colorectal non-neuroendocrine gastrointestinal cancers.

MATERIALS AND

METHODS

A systematic review and meta-analysis was conducted to compare surgical treatment versus non-surgical management in patients with non-colorectal non-neuroendocrine gastrointestinal cancers and metachronous liver metastases. PubMed/MEDLINE, Scopus, and the Cochrane Library were searched for comparative studies published in English from 1 January 2005 to 8 December 2025. Studies reporting overall survival outcomes were included. Overall survival at 1, 3, 5 years was analyzed using relative risks (RR) with 95% confidence intervals (CI), and pooled estimates were calculated using a random-effects model. Between-study heterogeneity was assessed using the I2 statistic.

RESULTS

Ten comparative studies were included. Surgically treated patients showed longer median overall survival. When survival was analyzed at fixed time points, surgical treatment was associated with significantly higher overall survival at 1 year compared with non-surgical management (RR=1.93, 95% CI=1.26-2.98), with a similar, though not statistically significant, trend favoring surgery at 3 years (RR=2.45, 95% CI=0.99-6.11) and 5 years (RR=2.26, 95% CI=0.97-5.29). Analyses showed substantial heterogeneity (I2=67-86%), reflecting important clinical and methodological variability across studies and the likely influence of patient selection in the surgical cohorts.

CONCLUSION

Surgical treatment of metachronous liver metastases from non-colorectal non-neuroendocrine gastrointestinal cancers was associated with longer median overall survival and significantly higher overall survival at 1 year compared with non-surgical management, with a favorable but not statistically significant trend at 3 and 5 years.