title: Effects of lifestyle and single nucleotide polymorphisms on breast cancer risk: a case-control study in Japanese women.
abstract: BACKGROUND
  Lifestyle factors, including food and nutrition, physical activity, body composition and reproductive factors, and single nucleotide polymorphisms (SNPs) are associated with breast cancer risk, but few studies of these factors have been performed in the Japanese population. Thus, the goals of this study were to validate the association between reported SNPs and breast cancer risk in the Japanese population and to evaluate the effects of SNP genotypes and lifestyle factors on breast cancer risk.
  
  
  METHODS
  A case-control study in 472 patients and 464 controls was conducted from December 2010 to November 2011. Lifestyle was examined using a self-administered questionnaire. We analyzed 16 breast cancer-associated SNPs based on previous GWAS or candidate-gene association studies. Age or multivariate-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were estimated from logistic regression analyses.
  
  
  RESULTS
  High BMI and current or former smoking were significantly associated with an increased breast cancer risk, while intake of meat, mushrooms, yellow and green vegetables, coffee, and green tea, current leisure-time exercise, and education were significantly associated with a decreased risk. Three SNPs were significantly associated with a breast cancer risk in multivariate analysis: rs2046210 (per allele OR=1.37 [95% CI: 1.11-1.70]), rs3757318 (OR=1.33[1.05-1.69]), and rs3803662 (OR=1.28 [1.07-1.55]). In 2046210 risk allele carriers, leisure-time exercise was associated with a significantly decreased risk for breast cancer, whereas current smoking and high BMI were associated with a significantly decreased risk in non-risk allele carriers.
  
  
  CONCLUSIONS
  In Japanese women, rs2046210 and 3757318 located near the ESR1 gene are associated with a risk of breast cancer, as in other Asian women. However, our findings suggest that exercise can decrease this risk in allele carriers.
authors.forename: Taeko
authors.initials: T
authors.lastname: Mizoo
authors.affiliation: Department of General Thoracic Surgery and Breast and Endocrinological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama-city, Okayama 700-8558, Japan. ntaira@md.okayama-u.ac.jp.
authors.forename: Naruto
authors.initials: N
authors.lastname: Taira
authors.forename: Keiko
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nogami
authors.forename: Takayuki
authors.initials: T
authors.lastname: Iwamoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Motoki
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Shien
authors.forename: Junji
authors.initials: J
authors.lastname: Matsuoka
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Doihara
authors.forename: Setsuko
authors.initials: S
authors.lastname: Ishihara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawai
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kawasaki
authors.forename: Youichi
authors.initials: Y
authors.lastname: Ishibe
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ogasawara
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Komoike
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Miyoshi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D044466:Asian People / Q000235:genetics; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D011159:Population Surveillance; D012306:Risk