# Requirements for a successful implementation of liver transplantation as a treatment option for non-resectable colorectal liver metastases into clinical routine – a narrative review

## TL;DR

Liver transplantation may offer better survival for some colorectal cancer patients with liver metastases who can't be treated surgically, but strict selection and policy changes are needed.

## Contribution

This review highlights liver transplantation as a potential treatment for non-resectable colorectal liver metastases and outlines requirements for its clinical implementation.

## Key findings

- Liver transplantation combined with chemotherapy showed a 73.3% 5-year survival rate compared to 9.3% with chemotherapy alone.
- Patients eligible for liver transplantation often have stable, liver-limited disease and meet strict molecular and metabolic criteria.
- Despite lung recurrences, liver transplantation still provides better overall survival than standard care.

## Abstract

Colorectal cancer remains a major challenge for the global health care system. Many patients with colorectal cancer develop liver metastases (CRLM), and a certain proportion of these patients are neither eligible for surgical nor interventional treatment. Liver transplantation (LT) could be a curative treatment option for these patients.

This narrative review was based on a targeted literature search of the National Library of medicine (PubMED) to identify current publications investigating LT as a treatment option for patients with CRLM without local treatment options. The search term “colorectal AND liver transplantation” was used, and only original articles of the last ten years were included. Additionally, the ClinicalTrials.gov registry was screened for ongoing clinical trials in this field.

A total of 6 studies were identified, along with 21 active clinical trials. LT was associated with higher survival rates compared to standard of care, e.g., 73.3% 5-year survival after LT plus chemotherapy vs. 9.3% after chemotherapy alone in the randomized TransMET trial. Candidates eligible for LT were most often identified based on stable, liver-limited disease under active chemotherapy, in addition to further strict selection criteria such as favorable molecular pathology and metabolic tumor volume. Patients were accordingly prioritized on the waiting list. Long-term follow-up revealed substantial recurrence rates across the studies, most occurring in the lungs. Despite these recurrences, overall survival remained superior to standard of care.

The reviewed evidence suggests that LT should be considered as part of a multimodal treatment algorithm for highly selected patients with non-resectable CRLM. This paradigm shift has already translated into several ongoing trials on this subject. Policy adjustments in organ allocation and the development of structured programs are necessary to establish LT for CRLM patients in clinical routine.