Fig. 1: Resectable and non-resectable colorectal liver metastasis.
From: Liver transplantation for non-resectable colorectal liver metastases: the thin red line
The resectable (green area) and non-resectable (red area) colorectal liver metastasis (CRLM) is overlapped by a ‘grey zone’ in which indications and protocols are being stretched to expand criteria for ‘resectable’ or ‘treatable’ CRLM by different modalities. Initial resection may be followed by new local treatment, e.g. ablation for a recurrence. Transplantation is a modality, for which selection of candidates is based on time-dependent criteria and avoiding unfavourable biological factors (such as BRAF mutation) to prevent futility. Also, in unresectable CRLM with MSI/dMMR the use of first-line immunotherapy has proved to be an efficient treatment hence competing with the efficacy of transplantation. For every transplant, the numbers of patients who undergo resection is in the thousands and for non-resectable CRLM in the tens of thousands. Hence, transplantation for non-resectable CRLM represents a ‘thin red line’ and not the main defence for treating non-resectable CRLM. CEA carcinoembryonic antigen, EHD extrahepatic disease, MSI microsatellite instability, dMMR defect mismatch repair. Created in part with Biorender.com.
