In patients with advanced head and neck squamous cell carcinoma (HNSC), evidence of cell-mediated immunity and monocyte functional abnormalities has been reported. We studied the production of interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6) by peripheral blood monocytes from 22 patients with HNSC (12 larynx and ten oral cavity cancers) in comparison with monocyte cytokine production of age-matched healthy subjects. Pure monocytes were incubated with and without lipopolysaccharides (LPS) (10 micrograms ml-1) for 4 h at 37 degrees C and IL-1 beta and IL-6 concentrations were determined in supernatants by specific ELISA. There was no significant difference in IL-1 beta levels in monocyte supernatants from cancer in comparison to control subjects; conversely, a higher IL-6 production by unstimulated and LPS-activated cells from HNSC patients than from controls was found. No relationship was observed between cytokine production and cancer stage. The regression analysis evidenced a significant correlation between IL-1 beta and IL-6 monocyte-release in HNSC patients and in controls, so suggesting a possible autocrine control of IL-6 production by other cytokines.