Abstract P4-03-14: Proinflammatory Dietary Patterns and Risk of Total and Subtypes of Breast Cancer Among US Women

Abstract

Abstract Background: Dietary patterns promoting chronic inflammation, including the empirical dietary inflammatory pattern (EDIP), have been shown to strongly influence risk of weight gain, type 2 diabetes, cardiovascular disease, and colorectal cancer. However, it is unclear if this dietary pattern is associated with other tumors in which the mechanisms are not totally understood such as breast cancer. Methods: We prospectively followed 76,295 women from the Nurses’ Health Study (NHS, 1984-2016) and 91,078 women from the Nurses’ Health Study II (NHSII, 1991-2017). Diet was assessed by food frequency questionnaires (FFQs) every 4 years. The inflammatory potential of diet was evaluated using the previously established EDIP based on plasma C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha receptor 2 (TNF-αR2). Higher scores indicate higher inflammatory potential of the diet. Results: During 4,153,676 person-years of follow-up, we documented 10,632 invasive breast cancer cases (6,807 NHS; 3,825 NHSII). In the pooled multivariable-adjusted analyses, women in the highest, compared with the lowest, EDIP quintile were at higher breast cancer risk (HRQ5vsQ1=1.12; 95% CI 1.05, 1.20; P-trend< 0.001). This association was attenuated after adjusting for weight change since age 18 y, although it remained significant (HRQ5vsQ1=1.07; 95% CI 1.00, 1.14; P-trend=0.01). In subtype analyses, we found evidence that the inflammatory potential of diet influenced breast cancer risk differentially by ER status (P-heterogeneity=0.038) and by molecular phenotype (P-heterogeneity=0.007), with the association between EDIP and breast cancer limited to ER-negative tumors (HRQ5vsQ1=1.31; 95% CI: 1.11, 1.55; P-trend=0.002; for ER-positive tumors, HR Q5vsQ1=1.03; 95% CI, 0.96, 1.12;P-trend=0.10) and basal-like tumors (HRQ5vsQ1=1.78; 95% CI: 1.19, 2.65; P-trend=0.004). Further adjustment for weight change since age 18 y did not materially alter the association for these subtypes. Conclusions: Dietary patterns with high potential to contribute to chronic systemic inflammation, based on higher EDIP scores, were associated with a modestly increased risk of breast cancer, which was more pronounced for ER-negative and basal-like breast tumors. Citation Format: Andrea Romanos-Nanclares, Walter C Willett, Bernard A Rosner, Daniel G Stover, Sarah Asad, Sagar Sardesai, Michelle D Holmes, Wendy Y Chen, Rulla M. Tamimi, Fred K Tabung, A Heather Eliassen. Proinflammatory Dietary Patterns and Risk of Total and Subtypes of Breast Cancer Among US Women [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-14.