Natural killer cell activity in lung cancer patients.

A total of 50 lung cancer (CA) patients and 20 normal persons as controls were included in our study. We obtained lymphocytes from heparinized blood by Ficoll-Hypaque gradient method, and after the macrophages were removed, they were incubated with 51Cr-labelled K562 cells at concentrations of 100:1, 50:1, 12.5:1 for four hours. We calculated the cytotoxicity activity and lytic unit (LU) of natural killer (NK) cells. Significant impairment was noted in the comparison of NK cytotoxicity and LU between stage III-M1 lung CA patients (n = 28) and the control group. However, significant impairment was also noted in stage III-M1 and III-M0 patients. Four cases in stage I underwent surgery, and the NK cytotoxicity before the operation was noted to be low. After the operation, the NK cytotoxicity increased. These results indicate that NK cytotoxicity assay was impaired in stage III-M1 lung CA and also suggest that it may act as a therapeutic guide in determining the results of the operation.