Regional management of liver metastases. II.

Abstract

Metastatic cancer of the liver has a dominant influence upon survival despite the presence of metastasis in other sites. For patients with untreated liver metastases, the median survival after diagnosis is 75 days, and only 7% survived 1 year. Prognosis of hepatic metastasis is related to the extent of liver involvement, and various staging systems have been proposed (Table I.1). Hepatic metastases are quite resistant to conventional systemic chemotherapy. Surgical resection is the treatment of choice whenever possible, but the resectability rate is rather low and the surgical mortality relatively high. Patients with solitary metastasis and those with primary in the colon, especially females, have had the best results. Regional chemotherapy to the liver has the advantages of achieving higher local concentrations of drug, prolonging the contact of drug and tumor cells, and reducing systemic toxicity. Infusion catheter can be placed either percutaneously or directly at the time of celiotomy. Many reports show that hepatic IA infusion of chemotherapeutic agents (5FU or FUDR) can give favorable response in 55%-80% of the cases and can prolong survival in comparison with untreated patients or patients receiving systemic chemotherapy (Tables I.2 and I.3). Some investigators have added one or more other agents to improve the therapeutic results. For instance, patients who were refractory to 5FU or MMC given as a single IV drug responded to the combination infusion therapy. Evidence from animal and human studies have demonstrated that both primary and metastatic tumors in the liver receive their blood supply almost exclusively from the hepatic arterial system, whereas normal liver tissue has a double supply: the hepatic artery and the portal vein. Thus, deliberate ligation of the hepatic artery has been used as a treatment of metastatic tumors of the liver. From 1966 to 1981, some 518 patients were reported to have undergone this operation as compared to 2327 patients treated with hepatic IA infusion chemotherapy (Table I.4). Although selective necrosis of tumor nodules has been demonstrated after HAL, there is always a shell of viable malignant cells left at the periphery. Thus, several series have administered chemotherapeutic agents either to the distal hepatic artery or to branches of the portal vein to prevent tumor regrowth. Currently there is no definite evidence that HAL with added infusion chemotherapy to the liver gives better response and/or survival results than infusion chemotherapy via the hepatic artery only and/or via the portal vein branches. The availability of a totally implantable infusion pump represents a remarkable advance in long-term i