Backgrounds
Colorectal liver metastases were historically considered a contraindication to liver transplantation, but dismal outcomes for those with metastatic colorectal cancer and advancements in liver transplantation (LT) have led to a renewed interest in the topic. We aim to compare the current evidence for liver transplantation for non-resectable colorectal liver metastases (NRCLM) with the current standard treatment of palliative chemotherapy.

Methods
A systematic review and meta-analysis of proportions was conducted following screening of MEDLINE, EMBASE, SCOPUS and CENTRAL for studies reporting liver transplantation for colorectal liver metastases. Post-operative outcomes measured included one-, three- and five-year survival, overall survival, disease-free survival and complication rate.

Results
Three non-randomised studies met the inclusion criteria, reporting a total of 48 patients receiving LT for NRCLM. Survival at one-, three- and five-years was 83.3–100%, 58.3–80% and 50–80%, respectively, with no significant difference detected (p = 0.22, p = 0.48, p = 0.26). Disease-free survival was 35–56% with the most common site of recurrence being lung. Thirteen out of fourteen deaths were due to disease recurrence.

Conclusion
Although current evidence suggests a survival benefit conferred by LT in NRCLM compared to palliative chemotherapy, the ethical implications of organ availability and allocation demand rigorous justification. Concomitant improvements in the management of patients following liver resection and of palliative chemotherapy regimens is paramount.