Liver Transplantation for Unresectable Colorectal Liver Metastases: A Systematic Review and Meta-Analysis of Survival Outcomes.

Abstract

Palliative chemotherapy for unresectable colorectal liver metastases (uCRLM) yields poor long-term survival. Liver transplantation (LT) is an emerging curative option for highly selected patients with liver-only disease. We performed a systematic review and meta-analysis following PRISMA guidelines. Electronic databases were searched for studies evaluating LT for uCRLM. Overall survival (OS) from comparative studies was pooled using random-effects models. Risk of bias was assessed using Cochrane RoB 2 and ROBINS-I V2. Potential patient overlap between cohorts from the same transplant programs was assessed and, where present, only 1 report per cohort contributed to pooling. Seventeen studies were included, with 3 comparative studies providing data for meta-analysis. Pooled analysis favored LT over best alternative therapies (HR 0.45, 95% CI 0.28-0.72; P = .0009; I² = 3%). This estimate was not robust: the TransMet randomized trial contributed 63% of the pooled weight, and its exclusion rendered the effect nonsignificant (HR 0.64, 95% CI 0.30-1.35). Comparators were clinically heterogeneous, spanning chemotherapy alone, mixed best alternative therapy, and ALPPS, so the pooled hazard ratio should not be read as a single transferable estimate of transplant benefit. Narrative synthesis indicated 5-year OS rates reached 83% following strict biological selection. Post-transplant recurrence was frequent (72%-81.5%) but often amenable to curative-intent management. Referral data, available only from a conference abstract, suggest that approximately 10% of evaluated patients ultimately undergo LT. In highly selected patients with permanently unresectable, liver-confined CRLM, LT is associated with a survival advantage, although the pooled estimate rests principally on a single randomized trial and should not be generalized across the clinically distinct comparators from which it was derived. The benefit appears to be driven by identifying a ``biological elite'' through stringent selection and aggressive multidisciplinary management of recurrences. PROSPERO registration: CRD42025124542.