Effect of Omega-3 Fatty Acid and/or Aspirin on Colorectal Adenoma Prevention
Although EPA and aspirin were found to decrease adenoma recurrence for certain subtypes, they did not reduce the number of individuals with any colorectal polyps.
The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) and aspirin, in combination and separately, did not significantly reduce the proportion of individuals with at least 1 colorectal adenoma (polyp) in a population identified as being at high risk for colon cancer, according to a study published in The Lancet.
A UK-based team of researchers conducted a multicenter, randomized, double-blind, placebo-controlled, 2 x 2 factorial trial (The seAFOod; International Standard Randomized Controlled Trials Number registry, ISRCTN05926847) to determine the effect of EPA and aspirin, either separately or in combination, on patients with sporadic colorectal neoplasia.
The main outcome was the proportion of patients with 1 or more colorectal adenomas identified at surveillance colonoscopy.
A total of 709 patients, aged 55 to 73 years, were randomly assigned to 1 of 4 treatments: EPA-free fatty acid 2 g/d (n=179), aspirin 300 mg/d (n=177), both treatments (n=177), or placebo (n=176) for 12 months.
Adenoma outcome data were available for 163 members of the placebo group, 153 members of the EPA group, 163 members of the aspirin group, and 161 members of the combination treatment group.
Of the participants with available adenoma outcomes, the adenoma detection rates for the placebo, EPA, aspirin, and combination groups were 61%, 63%, 61%, and 61%, respectively. There was no evidence for an effect for EPA or aspirin (risk ratios, 0.98 and 0.99, respectively).
The majority of participants tolerated the EPA and aspirin. One or more adverse events were reported among 44% of participants in the placebo group, 46% in the EPA group, 39% in the aspirin group, and 45% in the combination treatment group.
A total of 146 gastrointestinal adverse events were reported in the EPA group, while the placebo, aspirin, and combination groups each had 85, 86, and 68, respectively; 2 upper-gastrointestinal bleeding events were reported in the EPA group, 3 in the aspirin group, and 1 in the placebo group.
Although treatment with EPA and/or aspirin was not associated with reduction in the proportion of patients with 1 or more colorectal adenoma, “[f]urther research is needed regarding the effect on colorectal adenoma number according to adenoma type and location,” the researchers concluded.
Hull MA, Sprange K, Hepburn T, et al; on behalf of the seafood Collaborative Group. Eicosapentaenoic acid and aspirin, alone and in combination, for the prevention of colorectal adenomas (seAFOod Polyp Prevention trial): a multicentre, randomised, double-blind, placebo-controlled, 2 x 2 factorial trial [published online November 19, 2018]. Lancet. doi: 10.1016/S014-6736(18)31775-6