Clinical implications of natural killer (NK) cytotoxicity in patients with squamous cell carcinoma of the uterine cervix

Natural killer (NK) activity in peripheral blood mononuclear cells (PBMC) from women with squamous cell carcinoma of the uterine cervix (SCCUC) was studied. PBMC were obtained from 26 previously untreated patients with SCCUC at different stages of disease according to the FIGO classification (5 at stage I, 4 at stage II, 5 at stage III, 6 at stage IVa, and 6 belonging to stage IVb), as well as from 23 healthy age-matched women. These cells were used as effectors against 51Cr-labeled K-562 target cells in standard 4-hr cytotoxic assays. The NK activity displayed by PBMC from patients with local stages of the neoplasm (I, II, III, and IVa) was found to be similar to that exerted by PBMC from healthy controls ( P > 0.05). Furthermore, there were no significant differences among mean values of NK activity in PBMC from women at these different stages of the disease ( P > 0.05). However, the NK activity detected in the PBMC of patients with distant metastatic spread of the disease (stage IVb) was significantly depressed with respect to both controls and patients at any other earlier stage ( P < 0.05). We conclude that a decrease in the NK activity present in PBMC from women with SCCUC coincides with distant tumoral dissemination of the disease.