Effects of a preoperative therapy with interleukin-2 on surgery-induced lymphocytopenia in cancer patients.

It is known that major surgery may determine immunosuppression. This side effect might have a prognostic significance particularly in cancer patients, in whom the decrease in host defenses during the postoperative period could promote the proliferation of possible micrometastases. Since antitumor immune response is an IL-2-dependent phenomenon, a study was started to evaluate the effects of a preoperative injection of IL-2 on surgery-induced immune changes in cancer patients. The study included 12 colon cancer patients, treated subcutaneously with IL-2 at a dose of 9 x 10(6) IU/m2 twice daily for 3 consecutive days before surgery. Patients underwent surgery within 36 h from IL-2 interruption. The results were compared to those found in a control group of 18 colon cancer patients. Mean number of lymphocytes, T lymphocytes and NK cells significantly decreased after surgery in control patients; on the contrary, no postoperative decrease in immune cells was seen in IL-2 group. No anesthesiologic or surgical complication was seen in patients pretreated with IL-2 before surgery. This preliminary study would suggest that a preoperative therapy with IL-2 is an effective and well tolerated medical approach to neutralize surgery-induced immunosuppression in cancer patients.