Interleukin-2 immunotherapy action on innate immunity cells in peripheral blood and tumoral tissue of pancreatic adenocarcinoma patients

Background and aims: Innate immunity cells play a crucial role in host anticancer defense: cancer patients with high levels of natural killer (NK) cells and eosinophils have a better prognosis. Recombinant interleukin-2 (rIL-2) immunotherapy stimulates innate immunity cells. This study aims to evaluate the toxicity of pre- and postoperative rIL-2 treatment and the effects on innate immunity both in peripheral blood and in cancer tissue of patients with resectable pancreatic adenocarcinoma. Materials and methods: Seventeen patients received high dose rIL-2 preoperative subcutaneous administration and two low dose postoperative cycles. We evaluated NK cell and eosinophil count in blood and in pancreatic surgical specimens. Results: Toxicity was moderate. In the early postoperative period, blood NK cells and eosinophils significantly increased compared to basal values (p < 0.02). Histopathological analysis did not find significant intratumoral infiltration of NK cells nor of eosinophils. Conclusions: Preoperative high dose rIL-2 administration is able to counteract surgery-induced deficiency of NK cells and eosinophils in peripheral blood in the early postoperative period, although it cannot overcome local mechanisms of immune tumor escape in cancer tissue. The amplification of innate immunity, induced by immunotherapy, may improve the control of metastatic cells spreading in the perioperative period. © 2008 Springer-Verlag.