Advances in neoadjuvant therapy for colorectal cancer with liver metastases.

Metastatic colorectal cancer (CRC) is most frequently seen in the liver. Resection of metastases remains the treatment of choice; however, the majority of patients are ineligible for surgery due to unfavorable location, size, or number of metastases; insufficient liver reserve; or extrahepatic disease. The activity of irinotecan- and oxaliplatin-based regimens as first-line therapy has prompted the investigation of these agents as neoadjuvant therapy in patients with resectable and unresectable disease. Although studies suggest considerable promise for a neoadjuvant strategy in patients with unresectable liver metastases, the heterogeneity, small size, and retrospective nature of many of these studies precludes drawing firm clinical conclusions at this time, especially in patients with resectable disease. Therefore large, prospective trials that examine the impact of preoperative chemotherapy in patients with initially unresectable or resectable liver metastases are needed. These trials must include well-defined criteria for resectability and clear reporting of the extent of resection.