Abstract 144: Dietary fat and cholesterol intake in relation to fatal breast cancer.
Authors: Boeke Caroline E. , Eliassen A. Heather , Chen Wendy Y. , Cho Eunyoung , Holmes Michelle D. , Rosner Bernard , Willett Walter C. , Tamimi Rulla M. 
Published: August 2014

Dietary fats are not strongly associated with breast cancer incidence in general, but it is unknown whether fat intake influences risk of developing more aggressive, fatal breast cancer. We evaluated intake of total fat, specific types of fat (saturated, monounsaturated, polyunsaturated, trans fat; omega 3 polyunsaturated; animal and vegetable), and cholesterol prior to cancer diagnosis in relation to fatal breast cancer risk in 88,627 women in the Nurses’ Health Study (NHS; 1980-2008) and 93,372 women in the Nurses’ Health Study II (NHS II; 1991-2009). Diet was assessed every 4 years using a semi-quantitative food frequency questionnaire. Breast cancer cases were confirmed with pathology reports and deaths were confirmed using the National Death Index. We calculated cumulative average percent calories from fat intake and used substitution models to adjust for macronutrient composition. For cholesterol, we adjusted for total energy intake using the residual method. We defined fatal cases as women with breast cancer who died and had breast cancer listed as their primary cause of death. There were 1149 fatal breast cancer cases in NHS and 206 fatal cases in NHS II. After adjusting for multiple risk factors for breast cancer, neither total fat nor types of fat were associated with risk of fatal breast cancer in NHS or NHS II. For example, compared with those in the lowest quintile of saturated fat intake, those in the highest quintile had a hazard ratio (HR) of 1.02 (95% CI: 0.75, 1.38; p-trend=0.80) in NHS and 1.14 (0.61, 2.13; p-trend=0.61) in NHS II. In NHS there was a suggestive positive association between cholesterol and fatal breast cancer (Q5 vs. Q1 HR: 1.28, 95% CI: 1.02, 1.61; p-trend=0.04); this association did not persist in NHS II (0.73; 95% CI: 0.41, 1.32; p-trend=0.44) but should be examined further. Long-term pre-diagnosis dietary fat intake was not associated with fatal breast cancer in these two large prospective cohort studies.

Cholesterol and percent calories from fat in relation to fatal breast cancer, Nurses” Health Study. Quartile 1 Quartile 2 Quartile 3 Quartile 4 Quartile 5 p-trend Nutrient HR HR (95% CI) HR (95% CI) HR (95% CI) HR (95% CI) Total fat Number of cases 230 231 211 224 253 Macronutrient and age-adjusted 1.00 1.05 (0.87, 1.26) 0.92 (0.76, 1.11) 0.92 (0.76, 1.11) 0.92 (0.76, 1.11) 0.17 Multivariable adjusted 1.00 1.05 (0.87, 1.26) 0.92 (0.76, 1.11) 0.92 (0.76, 1.11) 0.89 (0.73, 1.08) 0.10 Saturated fat Number of cases 204 209 232 243 261 Macronutrient and age-adjusted 1.00 1.04 (0.85, 1.27) 1.10 (0.89, 1.36) 1.06 (0.84, 1.35) 1.04 (0.77, 1.42) 0.70 Multivariable adjusted 1.00 1.03 (0.84, 1.27) 1.09 (0.88, 1.36) 1.05 (0.83, 1.34) 1.02 (0.75, 1.38) 0.80 Cholesterol Number of cases 188 192 247 239 283 Macronutrient and age-adjusted 1.00 1.09 (0.88, 1.33) 1.32 (1.08, 1.61) 1.19 (0.96, 1.48) 1.36 (1.09, 1.71) 0.01 Multivariable adjusted 1.00 1.08 (0.88, 1.33) 1.30 (1.06, 1.59) 1.16 (0.94, 1.44) 1.28 (1.02, 1.61) 0.04

Citation Format: Caroline E. Boeke, A. Heather Eliassen, Wendy Y. Chen, Eunyoung Cho, Michelle D. Holmes, Bernard Rosner, Walter C. Willett, Rulla M. Tamimi. Dietary fat and cholesterol intake in relation to fatal breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 144. doi:10.1158/1538-7445.AM2013-144