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Reports from several laboratories have established the existence in extracts of hu-

Purpose Abnormalities in lipid levels have been associated with colorectal neoplasm risk; however, few studies have adjusted for use of cholesterol-lowering medications. The objective of this study was to determine the association of plasma lipid levels with adenoma risk while accounting for statin medication use. Methods We included 254 subjects with advanced adenoma, 246 with single small adenoma, 179 with multiple small adenoma cases, and 403 controls participants in the Tennessee Colorectal Polyp Study who also had plasma lipid measurements performed. Data on the use of statin medications was available for 83.4% of these participants. The association between plasma lipids and adenoma risk was evaluated using logistic regression models. Results Participants in the highest quartile of HDL cholesterol (range 52 – 106 mg/dl) had an adjusted odds ratio of 0.49 (95% CI 0.23, 1.07), 0.35 (95% CI 0.13, 0.91) and 0.22 (95% CI 0.09, 0.54) for single small, multiple small, and advanced adenomas compared to the lowest quartile (range 12 – 34 mg/dl), respectively. Participants with the highest quartile of triglyceride levels (range 178 – 721 mg/dl) had an adjusted odds ratio of 2.40 (95% CI 1.26, 4.55), 1.67 (95% CI 0.66, 4.23) and 2.79 (95% CI 1.25, 6.23) for single small, multiple small, and advanced adenoma, respectively compared to the lowest quartile (range 40 – 84 mg/dl). When restricted to individuals with known statin medication use adjusting for statin use did not appreciably affect these results. Conclusions We found a direct association between triglyceride plasma levels and an inverse association between plasma HDL cholesterol levels and adenoma risk. Both effects were not appreciably changed when accounting for the regular use of statin medication.

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Objective-Fish oil supplementation may represent a potential chemopreventive agent for reducing colorectal cancer risk. Fish oil's mechanism of action is unknown but presumed to be related to eicosanoid modification. The purpose of this study was to evaluate the effects of fish oil supplementation on levels of urinary and rectal eicosanoids. Methods-We conducted a randomized, double-blind, controlled trial of 2.5 grams of fish oil per day compared to olive oil supplementation over a six month period. Study participants had a history of colorectal adenomas. Randomization was stratified based on the gene variant rs174535 in the fatty acid desaturase 1 enzyme (FADS1), which affects tissue levels of arachidonic acid. Results-A total of 141 subjects were randomized. Urinary prostaglandin E 2 metabolite (PGE-M) was measured at baseline, 3 months, and 6 months and rectal prostaglandin E 2 (PGE 2) at baseline and 6 months. Repeated measures linear regression was used to determine the effect of the intervention on each outcome measure. Overall, fish oil supplementation was found to reduce urinary PGE-M production compared to olive oil (P = 0.03). Fish oil did not reduce rectal PGE 2