Nutritional status and postoperative cytokine response in colorectal cancer patients

The present study was designed to investigate the relationship between pre-operative nutritional status and peri-operative regulation of the cytokine network, and to clarify its relation to clinical outcome in colorectal cancer patients. Protein-energy malnutrition was assessed using the creatinine height index. Peripheral venous blood samples were obtained peri-operatively, and the serum concentrations of interleukin (IL-)6, IL-1 receptor antagonist (ra), IL-6 soluble receptor (sR) C-reactive protein (CRP) and the percentage of peripheral neutrophils were determined. Excessive operative blood loss was associated with postoperative morbidity. Pre-operative malnutrition was associated with postoperative mortality when excessive bleeding occurred. Postoperative IL-6 response was exaggerated and postoperative IL-1ra response was suppressed in nutritionally depleted patients. The postoperative serum concentrations of IL-6sR in malnourished patients remained at the lowest levels when excessive bleeding occurred. In these patients, the percentage of peripheral neutrophils remained at high levels even after resolution of the postoperative cytokine storm. A marked activation of the pro-inflammatory cytokine network associated with a decreased antagonistic reaction and an increased consumption of IL-6sR became prominent in malnourished patients when they underwent intense surgical stress. These immunological disturbances may be relevant to neutrophil activation and subsequent clinical outcome.