Unresectable liver metastases in colorectal cancer: review of current strategies.

The objective of the treatment of colorectal cancer patients with unresectable liver metastases should be clearly defined at the outset. Potentially resectable patients should be distinguished from clearly unresectable patients. In defining resectability, it is important to take into account both anatomic characteristics and patient characteristic (comorbidities, symptoms, age). According to this evaluation, treatment should be tailored to each patient. The most widely accepted standard is doublet cytotoxic regimen plus biotherapy (anti-EGFR or anti-VEGF antibodies according to RAS status, but some patients could benefit from an intensified regimen, as triplet chemotherapy ± bevacizumab, or intraarterial treatments (hepatic arterial infusion, radioembolization or chemoembolization), in order to allow resectability. It is therefore very important to discuss the treatments with a multidisciplinary team, including an experienced surgeon, an interventional radiologist and an oncologist. On the other hand, some patients could benefit in terms of quality of life and decreased toxicity from less intense treatment when resection is not an objective. First-line monotherapy or a maintenance strategy with biotherapy and/or cytotoxics could be discussed with these patients, and treatment holidays should be considered in selected patients. Finally, in patients with secondary resection of liver metastases, specificity should be considered in choosing the best adjuvant treatment, such as response to preoperative treatment and individual risk of relapse, which many in some cases justify intensification with hepatic arterial infusion in an adjuvant setting.