Abstract 2786: Associations of erythrocyte ω-3 fatty acids with breast tissue ω-3 and inflammation
Authors: Roy Shuvro 
Published: August 2015

Large, prospective studies have shown that chronic inflammation is associated with increased breast cancer risk. Long-chain ω-3 polyunsaturated fatty acids [(LCω-3PUFA); including eicosapentaenoic (EPA; 20:5ω3), docosapentaenoic (DPA; 22:5ω3), and docosahexaenoic acids (DHA; 22:6ω3)], derived from intakes of fatty fish and fish oil supplements, have anti-inflammatory properties. Epidemiologic studies of circulating LCω-3PUFA are suggestive of an inverse association with breast cancer. However, it is not known what, if any, relationship there is between LCω-3PUFA in blood and in breast tissues. Further, no study has examined the association between circulating LCω-3PUFA and inflammatory markers within breast tissue.

We conducted a cross-sectional analysis in blood and breast tissues from 132 cancer-free women undergoing elective reduction mammoplasty. Women, ages ≥18 years (17 with parental permission) with no prior history of cancer, were recruited between 1997 and 2009 and completed a comprehensive questionnaire. Surgically removed breast tissues, erythrocytes and heparinized plasma samples were collected. Fatty acid analysis of erythrocyte membrane and breast tissue EPA, DPA, DHA, and α-linolenic acid (ALA; 18:3ω3), a short-chain ω-3 PUFA that does not hold anti-inflammatory properties, were performed using gas chromatography. Breast tissue C-reactive protein (CRP) and interleukins (IL) -6 and -8 were measured using ELISA assays. T-tests and analysis of variance (ANOVA) were used to evaluate differences in mean total LCω-3PUFA (defined here as the sum of EPA, DPA and DHA) and CRP concentrations by participant characteristics. Multiple-regression models were fitted to examine the associations of circulating ω-3 with breast tissue ω-3 and inflammation.

Erythrocyte ω-3 concentrations were positively associated with the same fatty acids in breast tissue. The strongest association was for DHA; women in the highest quartile of erythrocyte DHA had 39% higher tissue DHA compared to those in the lowest quartile (Ratio 1.39, 95% CI: 1.08-1.79; P-trend&lt;0.01). Increasing concentrations of erythrocyte LCω-3PUFA, particularly DHA, were inversely associated with breast CRP. Women in the upper 50th percentile of DHA had statistically significantly reduced breast CRP (Ratio 0.60, 95% CI: 0.37-0.99). There were no clear associations between any ω-3 PUFA and IL-6 or IL-8.

To our knowledge, this is the first observational study examine the association between circulating and breast tissue ω-3, and the first study to examine associations between circulating ω-3 and breast tissue inflammation. Our findings provide evidence of the biological mechanisms linking ω-3 intake, inflammation, and breast cancer susceptibility.

Citation Format: Shuvro Roy. Associations of erythrocyte ω-3 fatty acids with breast tissue ω-3 and inflammation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2786. doi:10.1158/1538-7445.AM2015-2786