The effects of surgical stress and psychological stress on the immune function of operative cancer patients

Surgical resection of solid tumors provides a major opportunity for cure in many patients, but unfortunately can also increase the risk of metastases by spilling of tumor cells into the circulation. Moreover, surgery has been shown to result in immunological changes including an impaired natural killer cell cytotoxicity (NKCC). This immunosuppression can be intensified by supportive cares such as anaesthesia and peri-operative blood transfusion. Additionally, psychological stress induced by cancer diagnosis and surgery can also impair immune function. These immunosuppressive factors may potentially provide a "fertile soil" for the outgrowth of circulating tumor cells. This review will focus on the influence of surgery and related methods such as bloodtransfusion and anaesthesia and on the detrimental effects psychological stress on the critical components in the host's natural and acquired immune responses to tumor cells.