The effect of cancer and chemotherapy on monocyte function.

Defective monocyte function has been described in human malignancies. This report assessed adherence and the production of hydrogen peroxide by peripheral blood monocytes in breast and lung cancer patients receiving cyclic chemotherapy. Monocyte adherence was similar in cancer patients and normal controls, and adherence was unchanged with chemotherapy. Release of hydrogen peroxide by adherent monocytes was measured before and after chemotherapy in 15 breast and 7 lung cancer patients and compared to cells from 15 normal controls. Monocytes from untreated breast cancer patients released significantly less hydrogen peroxide than controls (Breast = 75 +/- 17.7 nmol/10(6) monocytes; Controls = 150 +/- 19.2, p less than 0.05). Hydrogen peroxide release by monocytes decreased two weeks after chemotherapy in breast and lung cancer patients (Breast Post = 67 +/- 18.3; Lung Pre = 168 +/- 45.9; Post = 77 +/- 16.0, p less than 0.01). This effect was reversible as hydrogen peroxide release prior to the fourth chemotherapy cycle was greater than pre-chemotherapy levels. These findings suggest that chemotherapy causes a reversible impairment of monocyte function.