Liver-directed therapies for gastrointestinal malignancies

Although surgery remains the treatment of choice for hepatic malignancy, both primary and secondary, the majority of patients presenting with hepatic tumors are unfortunately not candidates for resection. A number of alternative hepatic-directed therapies are assessed for their role in the following settings: as primary treatment modalities; as treatment adjuvants to surgical resection, including neoadjuvant therapy to downstage tumors prior to planned resection; and as a means of palliation when tumors are incurable. Non-surgical hepatic-directed therapies demonstrated to prolong survival include adjuvant portal vein chemotherapy infusion at the time of resection of primary colorectal cancer, and hepatic artery infusion in the setting of established hepatic metastases. Several other therapies are described but remain incompletely evaluated, including transplantation, microwave coagulation, injection of radiolabeled particles, chemoembolization, percutaneous ethanol injection, and cryosurgery. Due to the rarity of these tumors, many studies present results of heterogeneous populations of patients, making meaningful comparison difficult. Finally, it must be said that screening asymptomatic patients after resection of colorectal cancer with a view to application of hepatic-directed therapy in the setting of colorectal metastases is costly.