PREOPERATIVE INTERLEUKIN-2 SUBCUTANEOUS IMMUNOTHERAPY MAY PROLONG THESURVIVAL-TIME IN ADVANCED COLORECTAL-CANCER PATIENTS

It has been demonstrated that surgery may induce immunosuppression. Th is finding could influence the clinical course of surgically treated c ancer patients. Moreover, preliminary experimental studies have shown that a preoperative injection of IL-2, whose importance in generating the antitumor immune response is well known, may neutralize surgery-in duced immunosuppression. At present, however, it is still unknown whet her preoperative IL-2-induced immune improvement in the postoperative period may influence the prognosis of surgically treated cancer patien ts. The present study was performed to evaluate the prognostic impact of IL-2 presurgical therapy in advanced colorectal cancer patients. Th e study included 50 colorectal cancer patients, Dukes' stage D, who we re randomized to be treated with or without IL-2 preoperatively(18 . 1 0(6) IU/day subcutaneously for 3 consecutive days). After surgery, all patients underwent chemotherapy with 5-FU and folates until disease p rogression. Postoperative mean numbers of lymphocytes, T lymphocytes, natural killer cells and activated lymphocytes were significantly high er in IL-2-treated patients than in controls. Moreover, the percent of lymphocytic and/or eosinophilic tumor infiltration was significantly higher in IL-2 group than in controls. Finally, both survival curve an d the percent of survival at 1 year were significantly greater in pati ents pretreated with IL-2 than in controls. This clinical trial demons trates that preoperative IL-2-induced neutralization of postoperative lymphocytopenia is associated with a prolonged survival time in advanc ed colorectal cancer patients.