Natural killer cell activity in patients with carcinoma of the larynx and hypopharynx

Natural killer (NK) cells have recently gained much attention as potential effector cells in antitumor and antiviral immune defense mechanisms. The role of NK cells in patients with squamous cell carcinoma has not yet been described. In our study of larynx and hypopharynx cancer patients, no correlation was found with the extent of the disease expressed by the TNM classification or the TNM staging. Furthermore, no change of the spontaneous natural killer cell mediated K562 lysis was shown in advanced malignant disease or in the postoperative period up to 24 months following surgery. When the NK cell activity was compared with two control groups of healthy volunteers, aged 20 to 30 or 55 to 65 years, both with high alcohol and tobacco consumption, no alterations of the killing capacity for K562 targets were observed during aging, with or without a tumor. NK cell cytotoxicity was significantly lower in tumor draining lymph nodes of the neck than the values found in peripheral blood. In cancer patients as well as in healthy donors, the spontaneous killer cell activity was significantly enhanced by incubation with beta-interferon. The differences, however, between natural killing in peripheral blood and lymph nodes were increased in the head and neck cancer population mainly by an overall reduced NK cell cytolysis in the tumor draining lymph nodes. Although none of the lymph nodes used was infiltrated by malignant cells as seen under microscopic examinations, the diminished NK cell activity in laryngeal and hypopharyngeal cancer patients seems to be caused by factors or the presence of locoregional suppressor cells capable of reducing natural cell mediated immunity.