Failure of cell-mediated effector mechanisms in lung cancer.

The status of cell-mediated effector mechanisms was studied in 28 patients with lung cancer (25/28 in stage III). Patients' precultured peripheral blood mononuclear leukocytes, isolated by Ficoll-Hypaque, were tested for lymphocyte proliferation responses to alloantigens in mixed lymphocyte culture (MLC). The influence of autologous patients' sera was studied further on MLC responses from patients and controls. Cell-mediated lympholysis (CML), with the use of allogenic blast cells as targets, and antibody-dependent cell-mediated cytotoxicity (ADCC) against human red blood cells also were tested. Major differences between the cancer patients and controls were not demonstrated by MLC. Inhibition or enhancement of MLC responses by the autologous serum was shown; bimodal influence was significant; 72% of the sera caused inhibition and 28% caused enhancement. CML was depressed in 54% of the patients, and ADCC was depressed in 50%. The decrease in both cytotoxic responses was significant (P less than .005). Thirteen patients died after initiation of the investigative protocol; in 11 of 13, CML or ADCC was diminished. The altered cytotoxic capabilities were more prevalent among the epidermoid type, including the deceased patients. This study provides evidence that a severe impairment of cell-mediated effector mechanisms is frequent in advanced lung cancer and may be associated with poor clinical course and with the histologic type.