Immunomodulating effects of surgical intervention in tumors of the head and neck.

The immunomodulating effect of primary surgical intervention in 33 patients with squamous cell carcinoma of the oral cavity, pharynx, and larynx was analyzed prospectively. An operation time of longer than 7 hours was significantly associated with a decrease of total lymphocyte counts, CD4(+) T lymphocytes, and CD8(+) T lymphocytes. The CD4/CD8 ratio as a marker for the downregulation of the cellular immune response was slightly decreased but still in the normal range. CD4(+) lymphocyte counts increased within 7 days, and CD8(+) lymphocytes increased 4 weeks after the operation. The in vitro stimulation of the lymphocytes was impaired for 1 to 4 weeks. Release of interleukins, interferon-gamma, and tumor necrosis factor-alpha remained low despite the surgical trauma. The decreased lymphocyte counts, especially CD4(+) and CD8(+) lymphocytes, were significantly associated with duration of operation and volume of blood loss. Extension of trauma, age, type of anesthesia, and type of intensive care intervention were not associated with specific immunomodulating effects. However, these factors might be responsible for suppression of the immune system, which is expressed by lymphocyte depletion, lymphocyte dysfunction, and impaired upregulation of cytokine secretion.