LIVER TRANSPLANTATION FOR UNRESECTABLE COLORECTAL LIVER METASTASES: POOLED REAL-WORLD DATA FROM ALL BELGIAN LIVER TRANSPLANT CENTRES.

Introduction: Liver transplantation (LTx) for unresectable colorectal liver metastases (uCLM) has
recently gained renewed interest, particularly following the 2024 publication of the TransMet trial, which
provided prospective, randomized evidence supporting the oncologic potential of this strategy in highly
selected patients. This has led to an increased demand of LTx for uCLM in all Belgian transplant centres,
albeit in the absence of a nationally harmonized protocol during this period of early clinical adoption.
Recognizing the growing number of individual cases and the heterogeneity in selection criteria, we sought
to retrospectively collect and analyse all Belgian cases of LTx performed for uCLM to date. Especially
taken into account that the total number of patients transplanted for this indication in TransMet (38),
SECA-I (21) and SECA-II (15) remains modest. Although these initial Belgian cases were not performed
under a uniform protocol, this national, multi-centre, retrospective cohort offers a timely and relevant
snapshot of clinical practice just prior to the launch of a nationally agreed-upon framework for the
indication of LTx in uCLM.
Aim: Assess and consolidate current real-world data to inform future practice and contribute to the broader
international discourse on this emerging indication.
Methods: This multicentre retrospective study included all LTx cases performed for uCLM across
the six accredited Belgian LTx centres. Patient selection at each centre followed local protocols,
which varied and often differed from the exact TransMet protocol. However in all cases, CLM
were classified as permanently unresectable and there was no prior history of extrahepatic disease.
Results: Between June 20, 2016 and August 31, 2025, 29 patients underwent LTx for uCLM in Belgium.
Patients had a median age of 56 years (IQR 50 – 61) and 20 (69%) of 29 patients were male and 9 (31%)
were female. 23 (79%) of 29 primary colorectal tumours were left sided, 4 (14%) were right sided, 2
(7%) had a rectal tumour. 27 (93%) of 29 patients had synchronous CLM and 2 (7%) had metachronous metastatic disease. All tumours were pMMR/MSS, 2 (7%) of tumours had a KRAS mutation, 2 (7%) had
a BRAF mutation and 25 (86%) were RAS/BRAF wild type. At liver transplantation patients received
a median of 22 chemotherapy cycles (IQR 16−28) in up to two lines of chemotherapy. During first-line
chemotherapy, 18 (62%) had received doublet chemotherapy and 11 (38%) had received triplet regimens;
27 (93%) of 29 had targeted therapy. Serious adverse events occurred in 18 (62%) of 29 patients who
underwent liver transplantation. Three patients had an acute rejection, no patient was retransplanted, one
patient died from intraoperative haemorrhage. Median follow-up was 20.5 months (IQR 7.0−35.3). 11
(38%) of transplanted patients had a recurrence, in 8 (73%) the site was pulmonary, in 3 (27%) it was
peritoneal. The median time to recurrence was 6.3 months (IQR 5.3−6.7). 2-year progression-free survival
(PFS) was 35.7% (95% CI 12.8–64.9) among 14 patients eligible for analysis; 1-year PFS was 47.6%
(95% CI 25.7–70.2) among 21 patients. 2-year overall survival (OS) was 53.3% (95% CI 43.3–74.1)
among 15 patients eligible for analysis; 1-year OS was 68.2% (95% CI 45.6–85.8) among 22 patients.
The two BRAF-mutated patients in this cohort have follow-ups of 36 and 110 months, respectively, and
are alive without relapse.
Conclusions: LTx for uCLM is feasible in Belgian practice, with encouraging short-term outcomes
despite heterogeneous selection criteria and relatively short follow-up. However the recurrence rate was
high despite the limited timeframe, though notably, no hepatic recurrences were observed. Our results
suggest BRAF status alone (among other mutations) should not exclude patients from LTx; disease control
and behaviour might be more relevant. These retrospective findings should be interpreted cautiously but
support further uptake of LTx in clinical practice, while emphasizing the importance of a standardized
national protocol to optimize patient selection and improve long-term outcomes.