Safety and feasibility of chemotherapy followed by liver transplantation for patients with definitely unresectable colorectal liver metastases: insights from the TransMet randomised clinical trial.

Background: Despite the increasing efficacy of chemotherapy (C), the 5-year survival rate for patients with unresectable colorectal liver metastases (CLM) remains around 10%. Liver transplantation (LT) might offer a curative approach for patients with liver-only disease, yet its superior efficacy compared to C alone remains to be demonstrated.

Methods: The TransMet randomised multicentre clinical trial (NCT02597348) compares the curative potential of C followed by LT versus C alone in patients with unresectable CLM despite stable or responding disease on C. Patient eligibility criteria proposed by local tumour boards had to be validated by an independent committee via monthly videoconferences. Outcomes reported here are from a non-specified interim analysis. These include the eligibility of patients to be transplanted for non resectable colorectal liver metastases, as well as the feasibility and the safety of liver transplantation in this indication.

Findings: From February 2016 to July 2021, 94 (60%) of 157 patients from 20 centres in 3 countries submitted to the validation committee, were randomised. Reasons for ineligibility were mainly tumour progression in 50 (32%) or potential resectability in 13 (8%). The median delay to LT after randomisation was 51 (IQR 30-65) days. Nine of 47 patients (19%, 95% CI: 9-33) allocated to the LT arm failed to undergo transplantation because of intercurrent disease progression. Three of the 38 transplanted patients (8%) were re-transplanted, one of whom (3%) died post-operatively from multi-organ failure.

Interpretation: The selection process of potential candidates for curative intent LT for unresectable CLM in the TransMet trial highlighted the critical role of an independent multidisciplinary validation committee. After stringent selection, the feasibility of LT was 81%, as 19% had disease progression while on the waiting list. These patients should be given high priority for organ allocation to avoid dropout from the transplant strategy.

Funding: No source of support or funding from any author to disclose for this work. The trial was supported by the Assistance Publique - Hôpitaux de Paris (AP-HP).