Optimal patient selection beyond the current selection criteria for liver transplantation for unresectable colorectal liver metastasis.

Liver transplantation (LT) is a potentially curative treatment option for patients with unresectable colorectal liver metastases (CRLM). Despite numerous reports of favorable overall survival following LT for CRLM by several high-volume transplant centers, recurrence-free survival remains far from satisfactory. Given the invasiveness of the procedure, the scarcity of deceased-donor organs, and the potential risks to living donors, optimal patient selection is crucial. Currently, several prognostic factors are used for selecting good candidates for LT for CRLM, including tumor burden, extrahepatic metastases, gene mutation profile, and response to chemotherapy. To this end, several scoring systems based on traditional prognostic factors have been proposed. This review also discusses the prognostic factors that are not incorporated into standard LT program criteria but may serve as novel eligibility markers to improve patient selection, including metabolic tumor volume assessed by PET/CT, ctDNA, and the presence of perihepatic lymph node metastases. Routine pathological assessment of perihepatic lymph nodes prior to LT may be especially warranted because a high liver tumor burden is correlated with an increased incidence of perihepatic lymph node metastases. Further clinical studies and results from ongoing LT trials are needed to validate the clinical utility of these proposed prognostic factors.