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

ABSTRACT Background Resection is the foundation for cure for CRC liver metastases; however, only 20% of patients are suitable for surgery. Those suitable would be considered for resection or local therapies prior to being considered for regional therapies. Non-curative treatment is usually systemic chemotherapy. For patients with liver-only or liver-predominant metastases that are unresectable, regional therapies (cTACE, DEB-TACE and TARE) may be considered. Herein is a review of the current evidence for regional therapies for CRC liver metastases. Methods Literature searches (1/2000 to 3/2019 or 1/2010 to 3/2019 depending on the specific systematic review question) were conducted, including MEDLINE, EMBASE, Cochrane library and 2018 ASCO abstracts. Results 4100 articles were identified; fifteen studies were included in the review. There was 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. Conclusions Limited evidence supports the use 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.