Immunobiology of head and neck cancer.

The development of head and neck cancer (HNC) is strongly influenced by the host immune system. Recent evidence for the presence of functional defects and for apoptosis of tumor-infiltrating as well as circulating T cells in patients with HNC emphasizes the fact that their antitumor responses are compromised. It appears that H&N tumors not only effectively escape from the host immune system but also actively corrupt the host antitumor response via several distinct mechanisms. Strategies for restoring immune competence of patients with HNC and for preventing tumor escape are necessary for more effective control of tumor progression. New immunotherapeutic approaches include cytokine-based and DC-based vaccines which are aimed at the restoration of tumor-specific responses and at the protection of immune cells from tumor-induced apoptosis.