Identification of lymphocyte subsets and natural killer cells in head and neck cancers. An immunohistological study using monoclonal antibodies.

We investigated host-immune defenses against head and neck cancer cells by using various monoclonal antibodies with an immunoperoxidase technique to define lymphocyte subsets and natural killer (NK) cells. By so doing, we were able to identify lymphocyte subsets and NK cells in various head and neck cancers. We found that the majority of these cells infiltrate in or around nests of cancer cells and are stained with Leu-1 antibody. They include both Leu-2a and Leu-3a positive cells, which show equally intense levels of infiltration. Leu-7 positive cells were only scattered in the peripheral portion of the cancer nests in some cases. We also found a tendency for T-cells to infiltrate more intensely in poorly differentiated squamous cell carcinomas (SCC) than in moderately or well-differentiated SCC. Similarly, T-cells were more prevalent in maxillary carcinomas than in laryngeal carcinomas. These findings suggest the presence of a host-immune defense mechanism against cancer cells in patients with head and neck cancers.