Regional Therapies for Colorectal Liver Metastases: Systematic Review and Clinical Practice Guideline

Resection is the foundation for cure for colorectal cancer (CRC) liver metastases; however, only 20% of patients are suitable for surgery. Those suitable would be considered for resection or local therapies before being considered for regional therapies. Noncurative treatment is usually systemic chemotherapy. For patients with liver-only or liver-predominant metastases that are unresectable, regional therapies [conventional transarterial chemoembolization (cTACE), drug-eluting bead transarterial chemoembolization (DEB-TACE), and transarterial radioembolization (TARE)] may be considered. We review the current evidence for regional therapies for CRC liver metastases.

Literature searches (January 2000 to March 2019 or January 2010 to March 2019 depending on the specific systematic review question) were conducted, including Medline, Embase, Cochrane Library, and 2018 American Society of Clinical Oncology (ASCO) abstracts.

A total of 4100 articles were identified; 15 studies were included in the review. There were no comparative data regarding the resectable population. There was either insufficient evidence (cTACE or DEB-TACE) or evidence against (TARE) the addition of regional therapies to systemic therapy in the first line in the unresectable population. There was either no evidence (cTACE) or weak evidence (DEB-TACE or TARE) for the addition of regional therapies with or without systemic therapy in the second line or later in the unresectable population.

Limited evidence supports the delivery of percutaneous regional therapies in patients with unresectable CRC liver metastases. There are strong data demonstrating positive effects of TARE within the liver, but they do not translate to a benefit in patient-important outcomes. DEB-TACE appears to offer a survival benefit in the second-line setting, although the evidence is limited by small sample size and larger trials are needed.