Abstract P3-07-10: Effect of lifestyle and single nucleotide polymorphisms on breast cancer risk: A case-control study in Japanese women

Abstract

Abstract [Background] Lifestyle, including diet and physical activity, and birth/breastfeeding history are known to affect the risk for breast cancer. A correlation between single nucleotide polymorphisms (SNPs) and breast cancer risk has also been suggested in some reports, but the gene-environment interaction with breast cancer risk has not been examined widely. [Methods] The subjects were 476 breast cancer patients and 528 controls who attended a health check and had no history of breast cancer. Lifestyle was examined using a questionnaire with 48 questions about diet, physical activity, smoking habits, alcohol intake, and birth/breastfeeding history, etc. Based on past reports, we analyzed 6 SNPs (TNRC9-rs3803662, LSP1/11q-rs3817198, MAP3K1-rs889312, 8q24-rs13281615, 5p12-rs981782, and TGFβ1-rs1800470) using blood samples, and calculated age-adjusted odds ratios in a multiple logistic regression analysis. [Results] The study was performed from December 2010 to November 2011. Lifestyle factors (age-adjusted odds ratio, [95% confident interval]) found to have a significant correlation with development of breast cancer included BMI (1.041, [1.00–1.08]), smoking history (2.28, [1.45–3.65]), small number of births (1.18, [1.05–1.34]), no exercise during leisure time (1.36, [1.06–1.77]), low intake of green and yellow vegetables (1.69, [1.01–2.85]), and low intake of mushrooms (1.58, [1.05–2.39]). Stratified analysis based on menopause status showed that smoking history (1.85, [1.00–3.49]) and low intake of green and yellow vegetables (2.5, [1.03–5.88]) were significant risk factors before menopause, and that smoking history (2.28, [1.45–3.65]), low intake of green and yellow vegetables (2.24, [1.09–4.68]), no exercise during leisure time (1.67, [1.19–2.36]), small number of births (1.49, [1.25–1.78]), and no breastfeeding history (1.03, [1.01–1.06]) were significant risk factors after menopause. The results of SNP analysis suggested that TNRC9-rs3803662 was a significant risk factor in women before menopause (2.29, [1.25–4.25]). However, in multivariate analysis including lifestyle factors and SNPs, only smoking history emerged as a significant risk factor in women before menopause. [Conclusion] A correlation between lifestyle and breast cancer risk was found in this study, consistent with previous findings. Lifestyle and environmental factors such as births and breastfeeding may be more important than SNPs as risk factors for breast cancer. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-07-10.