The effect of surgery on natural killer cell activity in head and neck cancer patients: In vitro reversal of a postoperatively suppressed immunosurveillance system

Curative surgery diminished natural killer (NK) cell activity in 17 patients with previously untreated squamous cell carcinoma of the head and neck (37% ±17%, preoperatively i\s. 21% ±11%, postoperatively; p <0.001). This operativcly induced suppression was dependent on the presence of a nylon wool adherent cell population. With the removal of this surgically generated suppressor population from the in rilri) assay, postoperative suppression of natural killer activity was significantly diminished (21% ± 13%, vx. 30% ±23%, p < 0.01). The capability of fully restoring postoperatively suppressed NK cell activity was subsequently demonstrated by the synergistic effect of removing a nylon wool adherent suppressor population and stimulating NK cells with a naturally occurring im-niunopotentiator, tuftsin (from 21% ±13% to 41% ±23%; p <0.0001). In utilizing biological response modifiers in the perioperative period in the cancer patient, the interaction of these agents and the surgically generated suppressor cell population needs to be considered.