Natural killer cell cytotoxicity in the peripheral blood, cervical lymph nodes, and tumor of head and neck cancer patients

This study evaluated peripheral blood lymphocyte and lymph node lymphocyte natural killer (NK) cell activity in 22 patients with head and neck squamous cell carcinoma and eight patients undergoing surgery for nonmalignant conditions who served as controls. A novel mixed-model analysis of variance was used to analyze the results because of the inherent difficulties in data interpretation among heterogeneous groups when several concurrent variables impinge upon the results. The peripheral blood lymphocyte NK activity of cancer patients was significantly less than controls. In contrast, lytic activity from uninvolved draining lymph nodes of cancer patients was comparable to the activity of control nodes. However, if the node contained a small focus of metastatic tumor, NK activity was significantly diminished relative to uninvolved nodes from cancer patients or to control nodes. The mixed-model analysis of variance was particularly helpful in confirming this finding. Finally, NK lysis by tumor-infiltrating lymphocytes, purified from grossly metastatic nodes, was severely depressed. These data indicate that a spectrum of NK suppression exists in draining lymph nodes of head and neck squamous cell carcinoma patients, and that the level of activity depends upon the degree of nodal tumor involvement.