title: Isoflavones from phytoestrogens and gastric cancer risk: a nested case-control study within the Korean Multicenter Cancer Cohort.
abstract: BACKGROUND
  The role of soybean products in gastric cancer risk is not clear in epidemiologic studies due to measurement error from dietary intake questionnaires and due to different degrees of bias according to study design. To examine the association between soybean products and gastric cancer risk, we measured phytoestrogen biological markers in a nested case-control study.
  
  
  METHODS
  The study population was composed of 131 cases and 393 matched controls within the Korean Multicenter Cancer Cohort. The concentrations of the four biomarkers in the plasma samples were measured using time-resolved fluoroimmunoassay. Conditional and unconditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI).
  
  
  RESULTS
  Median plasma concentrations of genistein (229 nmol/L for controls, 181.8 nmol/L for cases; P=0.07) and daidzein (131.2 nmol/L for controls, 80.5 nmol/L for cases; P=0.04) in cases were lower than in controls, whereas equol concentrations were similar. Compared with the reference group, gastric cancer risk decreased in the highest groups for genistein (OR, 0.54; 95% CI, 0.31-0.93) and daidzein (OR, 0.21; 95% CI, 0.08-0.58). Higher equol concentrations were associated with a decreased risk for gastric cancer (OR, 0.50; 95% CI, 0.27-0.90). The combination of the highest concentrations for each isoflavone category was associated with a 0.09-fold decreased risk for gastric cancer compared with the combination of the lowest concentrations for each category. There was no association between plasma lignan concentrations and gastric cancer.
  
  
  CONCLUSIONS
  High serum concentrations of isoflavones were associated with a decreased risk for gastric cancer.
  
  
  CONCLUSIONS
  These results suggest a beneficial effect of high soybean product intake for gastric cancer risk.
authors.affiliation: Department of Preventive Medicine, Seoul National University College of Medicine, 103 Daehangno, Chongno-gu, Seoul 110-799, Korea.
authors.forename: Kwang-Pil
authors.initials: KP
authors.lastname: Ko
authors.forename: Sue K
authors.initials: SK
authors.lastname: Park
authors.forename: Boyoung
authors.initials: B
authors.lastname: Park
authors.forename: Jae Jeong
authors.initials: JJ
authors.lastname: Yang
authors.forename: Lisa Y
authors.initials: LY
authors.lastname: Cho
authors.forename: Chungwon
authors.initials: C
authors.lastname: Kang
authors.forename: Cheong Sik
authors.initials: CS
authors.lastname: Kim
authors.forename: Jin
authors.initials: J
authors.lastname: Gwack
authors.forename: Aesun
authors.initials: A
authors.lastname: Shin
authors.forename: Yeonju
authors.initials: Y
authors.lastname: Kim
authors.forename: Jeongseon
authors.initials: J
authors.lastname: Kim
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
authors.forename: Daehee
authors.initials: D
authors.lastname: Kang
authors.forename: Soung-Hoon
authors.initials: SH
authors.lastname: Chang
authors.forename: Hai-Rim
authors.initials: HR
authors.lastname: Shin
authors.forename: Keun-Young
authors.initials: KY
authors.lastname: Yoo
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000097:blood / Q000627:therapeutic use*; D007723:Korea; D008297:Male; D008875:Middle Aged; D048789:Phytoestrogens / Q000097:blood / Q000627:therapeutic use*; D012307:Risk Factors; D045730:Soy Foods; D013274:Stomach Neoplasms / Q000097:blood / Q000517:prevention & control*
chemical_list: D007529:Isoflavones; D048789:Phytoestrogens