Laparotomy enhances intraperitoneal tumor growth and abrogates the antitumor effects of interleukin-2 and lymphokine-activated killer cells.

The interrelationship between host resistance to cancer and the trauma of a surgical procedure is the subject of much speculation. Extensive study of animal models and human subjects is required to define these effects and to provide a theoretical model by which to interpret these data. We used a murine model of intraperitoneal cancer to demonstrate the augmentation of tumor growth by surgical trauma. In this intraperitoneal tumor model, a surgical procedure that included entry into the abdominal cavity resulted in augmented tumor growth; a surgical incision on the skin of the animal's back did not promote tumor growth. The immunotherapeutic effects of interleukin-2 and lymphokine-activated killer cells were significantly reduced by the performance of a laparotomy. This abrogation of the effects of the immunotherapeutic regimen was observed for up to 14 days after laparotomy but was lost by days 35 to 42. Healing tissue may promote tumor growth, and these effects are dominant over immunotherapy with interleukin-2 plus lymphokine-activated killer cells.