[The significance of a combination of hepatic artery pump reservoir and new immunotherapy for cancer (NITC) in the treatment of colorectal liver metastasis].

Infusion of anti-cancer agents through a hepatic artery pump reservoir has been reported as a relatively useful means of treating multiple liver metastases but its mechanism of action remains to be clarified. We thought that immune responses might be involved in the mechanism of action of this therapy and attempted to test this assumption in patients with colorectal liver metastases. When the patients were divided into two groups by survival period (the 24-week or longer survival group and the less than 24-week survival group), the 24-week or longer survival group had significantly higher Th1 cytokine levels (p<0.001-0.05) and significantly lower VEGF levels (p<0.01) than the less than 24-week survival group. The survival rate tended to be higher in patients for whom intra-arterial infusion therapy was combined with NITC. These results suggest that the combined therapy induces some kind of immune reaction closely related to tumor size reduction and prolonged patient survival. It seems necessary to compare immune activity during intra-arterial infusion therapy alone with activity during intra-arterial infusion treatment in combination with a new immunotherapy.