Paradoxical effects of 5-FU/folinic acid on lymphokine-activated killer (LAK) cell induction in patients with colorectal cancer.

The effects of treatment with 5-FU/folinic acid on interleukin-2 related lymphocyte responses was investigated in 21 patients with advanced colorectal cancer. The treatment was not suppressive of IL-2 related lymphocyte responses. Furthermore, at certain time points in the treatment cycles the capacity to generate lymphokine-activated killer (LAK) cells from the peripheral blood mononuclear cells of these patients was significantly augmented above that observed prior to treatment. These results provide a logical basis for the design of regimens which combine two approaches, each of low individual therapeutic efficacy, to treat patients with advanced colorectal cancer in the hope of increasing clinical response rates.