Limitations of molecular biomarkers in patients with resectable colorectal liver metastases

Biomarkers in colorectal liver metastases: Rising complexity and unknown clinical significance?

Surgical resection of the liver is the standard treatment for colorectal liver metastases, but 70% of patients still experience recurrence, resulting in limited survival. Molecular biomarkers promise guidance within the selection process of individualized treatment and provide better prognostic forecasting of recurrence and response to treatment. Presently, most investigated biomarkers include mutations of KRAS, BRAF, TP53, PIK3CA, APC, expression of Ki-67, and microsatellite instability. As some colorectal cancer tumors exhibit more than one molecular target, in line with a rising number of potential biomarkers, the complexity of their clinical implementation is rising steadily. Therefore, it is important to approach new insights into molecular biomarkers with explicit caution to their clinical applicability and significance, as there are contradictory results arising from multiple available studies and meta-analyses. This review helps to shed light on the complexity of promising biomarkers in both the prognosis and diagnosis of colorectal liver metastases.

Resectability and Ablatability Criteria for the Treatment of Liver Only Colorectal Metastases: Multidisciplinary Consensus Document from the COLLISION Trial Group

The guidelines for metastatic colorectal cancer crudely state that the best local treatment should be selected from a ‘toolbox’ of techniques according to patient- and treatment-related factors. We created an interdisciplinary, consensus-based algorithm with specific resectability and ablatability criteria for the treatment of colorectal liver metastases (CRLM). To pursue consensus, members of the multidisciplinary COLLISION and COLDFIRE trial expert panel employed the RAND appropriateness method (RAM). Statements regarding patient, disease, tumor and treatment characteristics were categorized as appropriate, equipoise or inappropriate. Patients with ECOG≤2, ASA≤3 and Charlson comorbidity index ≤8 should be considered fit for curative-intent local therapy. When easily resectable and/or ablatable (stage IVa), (neo)adjuvant systemic therapy is not indicated. When requiring major hepatectomy (stage IVb), neo-adjuvant systemic therapy is appropriate for early metachronous disease and to reduce procedural risk. To downstage patients (stage IVc), downsizing induction systemic therapy and/or future remnant augmentation is advised. Disease can only be deemed permanently unsuitable for local therapy if downstaging failed (stage IVd). Liver resection remains the gold standard. Thermal ablation is reserved for unresectable CRLM, deep-seated resectable CRLM and can be considered when patients are in poor health. Irreversible electroporation and stereotactic body radiotherapy can be considered for unresectable perihilar and perivascular CRLM 0-5cm. This consensus document provides per-patient and per-tumor resectability and ablatability criteria for the treatment of CRLM. These criteria are intended to aid tumor board discussions, improve consistency when designing prospective trials and advance intersociety communications. Areas where consensus is lacking warrant future comparative studies.