Ischaemic and metabolic treatment of hepatic tumours

For treatment of malignancies, physical and metabolic differences between tumour cells and host cells have guided the development of new approaches. In this review, two new approaches to be used in the treatment of liver malignancies are outlined: ischaemic therapy and interferences with the glucose metabolism. Ischaemic therapy of liver malignancies has been used in different forms during the last 20 years: from ligation of the hepatic artery, embolization of the arterial tree, transient occlusion of the hepatic artery to the present day use of temporary, intermittent, transient hepatic arterial occlusion. The beneficial effect of ischaemic therapy on malignancies is supposed to depend on oxygen and nutritional deficiency, formation of oxygen-derived free radicals and loss of function in cellular enzymes. The tumour cells seem thereby to be more sensitive than the host cells. Also, ischaemia might potentiate the effect of cytotoxic drugs. Intereferencies with glucose metabolism might be directed either towards the exaggerated tumour glycolysis, for example by glucose analogues like 2-deoxy-glucose, or towards the exaggerated host gluconeogenesis, for example by hydrazine sulphate. These treatments result in reduction of the glucose availability in the intracellular glucose metabolism in the tumour cells and have experimentally been demonstrated to be correlated to reduced tumour growth. It is concluded that both these approaches, ischaemic therapy and manipulations with the glucose metabolism, seem promising for the future. What is needed now is research to clarify the mechanisms behind the effects, to establish their full consequences, and to identify the clinical use of these treatments and their possible combinations.