173P Diet, genetic predisposition and the risk of breast cancer: A cohort study from the UK biobank

Abstract

Dietary factors have been consistently associated with breast cancer risk, but evidence for their effects in women with different genetic susceptibility of breast cancer is scarce, and little is known about their interaction with alcohol consumption. We analyzed data from 261,857 female participants in the UK Biobank. Multivariable adjusted Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between dietary factors and breast cancer risk. We further assessed its interaction with alcohol consumption and polygenic risk score (PRS) for breast cancer. Only processed meat and beef intake more than once a week were associated with a higher risk of breast cancer, especially in women who took alcohol ≥1/d [HR (95% CI):1.20(1.01, 1.42) and 1.35 (1.06, 1.73), respectively]. Fresh fruit intake was associated with reduced risk of breast cancer [HR (95% CI):0.76 (0.64, 0.89)]. There was an interaction between vegetable and fresh fruit intake and alcohol consumption (P for interaction<0.05). When further stratified by PRS, fresh fruit intake with ≥4 servings/d was associated with risk of breast cancer [HR(95% CI):0.87(0.78-0.96)] in women with the highest quantile of PRS, and additive interaction was found between them.Table: 173PAssociations between diet and any breast cancer, by frequency of alcohol consumptionIn women took alcohol <1/dIn women took alcohol ≥1/dHR(95%CI)HR(95%CI)Processed meatNever1.00 (REF)1.00 (REF)<once/wk1.10(1.01-1.18)1.08(0.91-1.29)≥once/wk1.08(1.01-1.17)1.20(1.01-1.42)BeefNever1.00 (REF)1.00 (REF)<once/wk1.04(0.95-1.14)1.27(0.99-1.63)≥once/wk1.05(0.96-1.16)1.35(1.06-1.73)Fresh fruit<2 servings/d1.00 (REF)1.00 (REF)2.0-2.9 servings/d0.99(0.94-1.06)0.90(0.80-1.02)3.0-3.9 servings/d0.99(0.93-1.05)0.92(0.80-1.05)≥4 servings/d0.89(0.83-0.96)0.76(0.64-0.89) Open table in a new tab . Processed meat, vegetable and fresh fruit were associated with risk of breast cancer, and the effect was stronger in those who took alcohol ≥1/d and with high PRS for breast cancer. A combined intervention by reducing alcohol and processed meat consumption while increasing vegetable and fresh fruit intake might contribute to the prevention of breast cancer in high risk women.