Perioperative Immunonutrition in Surgical Cancer Patients: A Summary of a Decade of Research

BACKGROUND: Immunonutrition is assumed to enhance immune system function. In surgical patients, it is supposed to reduce postoperative complications. However, results of recent clinical trials have been puzzling and have not supported this theory. AIM: The aim of our study was to evaluate the value of enteral and parenteral postoperative immunonutrition. METHODS: After initial evaluation of 969 patients, the intent-to-treat analysis included 776 patients (female 407, male 466, mean age 61.1 years) undergoing gastric or pancreatic resections between 2001 and 2009. All patients were randomly assigned after surgery to one of the following groups: standard enteral nutrition (SEN), immunomodulating enteral nutrition (IMEN), standard parenteral nutrition (SPN), or immunomodulating parenteral nutrition (IMPN). All malnourished patients received preoperative parenteral nutrition. Number and type of postoperative complications, length of hospitalization (length of stay [LOS]), and vital organ function were assessed. RESULTS: No statistically significant differences were observed in well-nourished patients, during either enteral or parenteral intervention, independent of the type of intervention (standard or immunomodulating). However, analysis of the malnourished group revealed the positive impact of enteral immunonutrition on reduction of postoperative complications (28.3 vs. 39.2 %, respectively; p = 0.043) and LOS (17.1 and 13.1 days, respectively; p < 0.05) compared with a standard enteral diet. The cross-analysis of SEN, IMEN, SPN, and IMPN was insignificant. CONCLUSIONS: The type of postoperative nutrition was of no importance in well-nourished patients. However, in malnourished patients, enteral immunonutrition helped to improve treatment outcome. These findings suggest its use as a method of choice during the postoperative period.