A progressive postoperative increase in the serum level of soluble receptors for interleukin-2 is an indicator of a poor prognosis in patients with gastric cancer.

Activated T lymphocytes release a soluble form of IL-2R (SoIL-2R) into the bloodstream, which can be detected by CD25 monoclonal antibody. Perioperative changes of serum levels of SoIL-2R and the number of CD25-positive cells were monitored simultaneously to clarify the clinical implications of SoIL-2R in patients with gastric cancer (n=91). Preoperative levels of SoIL-2R were significantly higher than in normal controls and levels were a useful indicator of possible lymph node involvement. Postoperative levels of SoIL-2R increased independently of the number of CD25-positive cells. Patients with progressive postoperative increases in levels of SoIL-2R had both a significantly high frequency of postoperative relapse and a poor prognosis. Increased SoIL-2R may reduce the availability of IL-2 by binding to it. Postoperative progressive increases in SoIL-2R appear to be a good indicator for a poor prognosis in patients with gastric cancer.