title: Plasma isoflavones and risk of primary liver cancer in Japanese women and men with hepatitis virus infection: a nested case-control study.
abstract: BACKGROUND
  Evidence suggests that estrogen plays a preventive role in primary liver cancer development, and it might be thought that isoflavones, which are structurally similar to estrogens and bind to estrogen receptors, are associated with the risk of liver cancer. We investigated this suspected association by measuring plasma concentrations of isoflavones in a nested case-control study of a population-based prospective cohort in Japan.
  
  
  METHODS
  From 18,628 target participants ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or hepatitis C virus infection at baseline (n = 1,544). Among these, 90 (28 women and 62 men) were newly diagnosed with primary liver cancer from 1993 through 2006; they were matched with 175 controls (54 women and 121 men). Plasma concentrations of isoflavones (genistein, daidzein, glycitein, and equol) were measured using triple quadrupole tandem liquid chromatography-mass spectrometry. The ORs of liver cancer development based on plasma concentrations were estimated with a conditional logistic regression model.
  
  
  RESULTS
  Basically, distributions of plasma isoflavone concentrations did not differ between the cases and controls. No statistically significant associations of genistein, daidzein, glycitein, and equol with primary liver cancer risk were found in either women or men.
  
  
  CONCLUSIONS
  In middle-aged Japanese women and men with hepatitis virus infection, plasma isoflavones were unassociated with the occurrence of primary liver cancer.
  
  
  CONCLUSIONS
  The role of isoflavones in liver carcinogenesis merits further study using both biomarkers and data on dietary intake of isoflavones. Cancer Epidemiol Biomarkers Prev; 24(3); 532-7. ©2014 AACR.
authors.affiliation: Environmental Epidemiology Section, Center for Environmental Health Sciences, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan. Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Michikawa
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. mnminoue@m.u-tokyo.ac.jp.
authors.forename: Manami
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Norie
authors.initials: N
authors.lastname: Sawada
authors.affiliation: Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Yamaji
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Iwasaki
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Taichi
authors.initials: T
authors.lastname: Shimazu
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Shizuka
authors.initials: S
authors.lastname: Sasazuki
authors.affiliation: The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Chiba, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.affiliation: Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006518:Hepatitis Viruses / Q000302:isolation & purification*; D006525:Hepatitis, Viral, Human / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D007529:Isoflavones / Q000097:blood*; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D007529:Isoflavones