Anesthesia and surgery: a double-edged sword for the cancer patient.

All therapeutic modalities used in cancer patients are associated with immunosuppression. Anesthesia and surgery represent a double-edged sword. By removal of gross tumor in many patients a restoration of general immune responses can be documented. In addition, circulating antigen or antigen-antibody complexes which block tumor-specific immune responses can be abrogated by removal of bulk tumor. However, animal data indicates that certain anesthetic agents and major surgical procedures may enhance growth of micrometastatic tumor foci. One mechanism by which this occurs might be immunosuppression. The use of immunorestorative drugs in the perioperative period has been able to reverse this phenomenon in animal tumor models.