Impact of postoperative omega-3 fatty acid-supplemented parenteral nutrition on clinical outcomes and immunomodulations in colorectal cancer patients.

AIM: To investigate the effect of omega-3 fatty acid parenteral supplementation postoperatively on clinical outcomes and immunomodulation in colorectal cancer patients. METHODS: Forty-two patients undergoing radical colorectal cancer resection with an indication for total parenteral nutrition postoperatively were enrolled in this prospective, double-blind, randomized, controlled study. Patients received total parenteral nutrition supplemented with either soybean oil (LCT; Intralipid, Fresenius-Kabi, SO group, n = 21) or a combination of omega-3 fish oil and soybean oil (LCT:fish oil = 5:1, fish oil; Omegaven, Fresenius-Kabi, FO group, n = 21), up to a total of 1.2 g lipid/kg per day for 7 d postoperatively. A same volume calorie and nitrogen was administrated. Routine blood test, biochemistry, systemic levels of IL-6 and TNF-alpha, percentage of CD3+, CD4+, and CD8+ lymphocytes were evaluated preoperatively and on postoperative d 1 and 8. Patient outcome was evaluated considering mortality during the hospital stay, length of postoperative hospital stay, and occurrence of infectious complications. RESULTS: Both lipid regimens were well tolerated. No differences between the two groups were noticed in demographics, baseline blood test, biochemistry, serum levels of IL-6 and TNF-alpha, percentage of CD4+, CD8+ lymphocytes, and ratios of CD4+/CD8+. Compared with those on postoperative d 1, serum IL-6 levels on postoperative d 8 were significantly depressed in the FO group than in the reference group (-44.43 +/- 30.53 vs -8.39 +/- 69.08, P = 0.039). Simultaneously, the ratios of CD4+/CD8+ were significantly increased in the FO group (0.92 +/- 0.62 vs 0.25 +/- 1.22, P = 0.035). In addition, depression of serum TNF-alpha levels (-0.82 +/- 2.71 vs 0.27 +/- 1.67, P = 0.125) and elevation of CD3+ and CD4+ lymphocyte percentage (12.85 +/- 11.61 vs 3.84 +/- 19.62, P = 0.081, 17.80 +/- 10.86 vs 9.66 +/- 17.55, P = 0.084, respectively) were higher in the FO group than in the reference group. Patients in the FO group tended to need a shorter postoperative hospital stay (17.45 +/- 4.80 d vs 19.62 +/- 5.59 d, P = 0.19). No statistically significant difference was found when stratified to mortality and occurrence of infectious complications. CONCLUSION: Postoperative supplementation of omega-3 fatty acids may have a favorable effect on the outcomes in colorectal cancer patients undergoing radical resection by lowering the magnitude of inflammatory responses and modulating the immune response.