Natural killer, lymphokine-activated killer and interferon-gamma producing activities of peripheral blood- and regional lymph node-mononuclear cells in 23 cases of colorectal cancer.

Natural killer (NK) activity, lymphokine-activated killer (LAK) activity and interferon-gamma (IFN-gamma) producing activity of peripheral blood mononuclear cells (PBMC) and regional lymph node mononuclear cells (LNMC) were studied in 23 previously untreated cases of colorectal cancer. NK and LAK activities were significantly lower in LNMC than in PBMC. Patients showed depressed NK and LAK activities in PBMC. In the Dukes C group, especially, both NK activity and LAK activity decreased compared to control patients. NK and LAK activities of PBMC decreased as the grade of invasion to lymphatic channels progressed. LAK activity positively correlated with NK activity in PBMC. Patients with high LAK activity showed high IFN-gamma production in both controls and Dukes A . B patients. However, in Dukes C patients, no relationship between LAK activity and IFN-gamma production was observed. We conclude that the depressed NK and LAK activities of PBMC reflect the local lymphatic invasion and that IFN-gamma involvement in LAK cell generation is impaired in advanced cancer patients. More fundamental studies should be carried out before clinical trials of adoptive immunotherapy using LAK cells, because LAK activity is not induced sufficiently in advanced cancer.