Locoregional Liver-Directed Therapies to Treat Unresectable Colorectal Liver Metastases: A Review

An estimated 70% of patients with colorectal cancer will develop liver metastases during the course of their disease. While the first-line treatment for hepatic metastases is resection, most patients with colorectal liver-only or liver-dominant metastases (CRLM) present with unresectable disease and are not surgical candidates. In the past decade, locoregional liver-directed therapies have demonstrated safety and efficacy in the treatment of patients with unresectable CRLM and chemotherapy-refractory disease. These treatments can be used to attempt conversion to surgical resectability, can control local disease progression, and have the potential to prolong survival. However, they have not yet become the standard of care in many practices. Each treatment has unique risks, and the clinical data are heterogeneous and thus difficult to interpret. In this article, we will review the most recent, high-impact literature on 3 common locoregional therapies used in the treatment of patients with unresectable CRLM: hepatic artery infusion pump chemotherapy, stereotactic body radiation therapy, and selective internal radiation therapy with yttrium-90 embolization. Ultimately, for this patient population, clinical decision-making requires a multidisciplinary discussion which should take into account individual patient characteristics and clinical expertise available at the treatment facility.