Liver-directed therapies in colorectal cancer.

The liver is the most common site of metastatic colorectal cancer (CRC) and the status of this organ is an important determinant of overall survival in patients with advanced disease. Complete resection of hepatic CRC metastases can provide a long-term cure for some patients, but the majority of liver metastases are not amenable to such surgery. Furthermore, most patients after curative resection ultimately suffer from recurrence, and the majority of such failures occur in the liver. Various ablative techniques can achieve local control of tumor after incomplete resection or for palliation. Tumor ablation currently has a secondary therapeutic role, as there is no evidence that it can achieve long-term survival comparable to surgical resection. Regional chemotherapy delivers tumoricidal agents in a selective fashion, minimizing systemic toxicity and damage to normal liver cells. Chemotherapy agents delivered through the hepatic artery can extend time to liver recurrence after curative resection and may prolong survival both in the adjuvant setting and when given to patients with unresectable disease. Molecular-based therapies, such as gene delivery and oncolytic viruses, provide promise for curative outcomes in patients with advanced disease.