[Immunological effects of locoregional immunochemotherapy for liver metastases of gastric cancer].

Nine gastric cancer patients with simultaneous liver metastases were given intermittent transarterial administration of chemotherapeutics (adriamycin, mitomycin C or 5-fluorouracil) and biological response modifiers (BRM; OK-432 and interleukin (IL) -2) after gastrectomy. In terms of direct antitumor effect on liver metastases, a partial response was observed in 4 of 9 cases (44%). In addition, the concentration of 3 kinds of cytokines such as IL-6, tumor necrosis factor (TNF) -alpha and interferon (IFN) -gamma in the peripheral blood sera was measured immediately before and after transarterial administration of agents. While the concentration of IL-6 increased by BRM, chemotherapeutics could not alter the level of IL-6. As for TNF-alpha and IFN-gamma, no particular changing pattern was observed after transarterial administration. Furthermore, natural killer (NK) activity of peripheral blood mononuclear cells was measured. Administration of either BRM or BRM in combination with chemotherapeutics caused a decrease in NK activity, whereas chemotherapeutics did not. Flow cytometric analysis using 3 kinds of monoclonal antibodies (Anti-CD16, CD56 and CD57) revealed that the proportion of subset of both highly activated NK cells (CD16+.CD56+.CD57-) and moderately activated NK cells (CD16+.CD56+.CD57+) reduced after administration of BRM.