Effect of antitumor surgery on soluble interleukin-2 receptor serum levels.

Surgically induced immunosuppression may play a role in cancer, because of the possible existence of micrometastases at the time of surgical removal of tumors. Antitumor immune reactions are mediated by interleukin-2 (IL-2). IL-2 acts on a specific IL-2 cell surface receptor; moreover, a soluble form of IL-2 receptor (sIL-2R) can be released in the blood. This study was carried out to evaluate the effect of surgery on sIL-2R serum levels in patients with operable solid tumors. A total of 48 patients with cancer and 11 controls who underwent major surgery for non-neoplastic disease were evaluated before and 7 days after surgery. Serum mean levels of sIL-2R were significantly higher after than before surgery in both the cancer and control groups. No correlation was seen between surgery-induced changes in sIL-2R and in T lymphocyte subsets. Because of its capacity of binding to IL-2, the increased blood concentrations of sIL-2R could reduce the IL-2 availability and negatively affect antitumor immune reactions.