Long-term outcomes after perioperative treatment with omega-3 fatty acid supplements in colorectal cancer

BACKGROUND: This study aimed to evaluate the effect of perioperative supplementation with omega-3 fatty acids (n-3 FA) on perioperative outcomes and survival in patients undergoing colorectal cancer surgery.

METHODS: Patients scheduled for elective resection of colorectal cancer between 2007 and 2010 were randomized to either an n-3 FA-enriched oral nutrition supplement (ONS) twice daily or a standard ONS (control) for 7 days before and after surgery. Outcome measures, including postoperative complications, 3-year cumulative incidence of local or metastatic colorectal cancer recurrence and 5-year overall survival, were compared between the groups.

RESULTS: Of 148 patients enrolled in the study, 125 (65 patients receiving n-3 FA-enriched ONS and 60 receiving standard ONS) were analysed. There were no differences in postoperative complications after surgery (P = 0·544). The risk of disease recurrence at 3 years was similar (relative risk 1·66, 95 per cent c.i. 0·65 to 4·26).The 5-year survival rate of patients treated with n-3 FA was 69·2 (95 per cent c.i. 56·5 to 78·9) per cent, compared with 81·7 (69·3 to 89·4) per cent in the control group (P = 0·193). After adjustment for age, stage of disease and adjuvant chemotherapy, n-3 FA was associated with higher mortality compared with controls (hazard ratio 1·73, 95 per cent c.i. 1·06 to 2·83; P = 0·029). The interaction between n-3 FA and adjuvant chemotherapy was not statistically significant.

CONCLUSION: Perioperative supplementation with n-3 FA did not confer a survival benefit in patients undergoing colorectal cancer surgery. n-3 FA did not benefit the subgroup of patients treated with adjuvant chemotherapy or decrease the risk of disease recurrence.