Superoxide anion (O,-) production by polymorphonuclear leukocytes (PMN) and monocytes (MN) was measured in the peripheral blood of 70 patients with lung cancer. The 0,-production by these cells was decreased in many, but not all, patients. The incidence of patients with lower 0,-production increased as the stage advanced. The correlation between 0,production by these cells and peripheral blood smears was evaluated in patients with cancer. Patients with 80% granulocytes and 40% monocytes or more in their peripheral blood had a significantly lower 0,-production by PMN and MN compared with those with less than 80% granulocytes and 40% monocytes, respectively. These results indicate that an abnormally increased number of granulocytes and monocytes in the peripheral blood of patients with cancer may depress immunoregulatory function. In addition, decreased 0,production by these cells should be considered when assessing the defense mechanisms and susceptibility to infection of these patients. Cancer 1992; 69~1682-1687.
Patients with cancer often have accompanying defective cellular and humoral immunity. Several investigators have shown that, in patients with malignant neoplasms, lymphocyte responsiveness is impaired not only in the tumor cells, but also to nonspecific mitogens."' Monocyte (MN) functions show decreased chemotaxis in most patients with cancer patient^.^ Others4 found a lower interleukin-1 release in patients with disseminated cancer. Decreased superoxide anion (0,J production was suggested in preliminary data obtained