title: Effect of coffee and green tea consumption on the risk of liver cancer: cohort analysis by hepatitis virus infection status.
abstract: In spite of their anticarcinogenic potential, the effect of coffee and green tea consumption on the risk of liver cancer has not been clarified prospectively in consideration of hepatitis C (HCV) and B virus (HBV) infection. We examined whether coffee and green tea consumption was associated with a reduced risk of liver cancer by hepatitis virus infection status in the Japan Public Health Center-Based Prospective Study Cohort II. A total of 18,815 subjects ages 40 to 69 years participating in a questionnaire and health checkup survey in 1993 to 1994 were followed for the incidence of liver cancer through 2006. A total of 110 cases of liver cancer were newly documented. Hazard ratios for coffee and green tea consumption categories were calculated with a Cox proportional hazards model. Compared with almost never drinkers, increased coffee consumption was associated with a reduced risk of liver cancer in all subjects (hazard ratio for <1, 1-2, and >or=3 cups/d; P(trend) = 0.67, 0.49, 0.54, and 0.025). A similar risk tendency was observed in those with either or both HCV and HBV infection. In contrast, no association was observed between green tea consumption and the risk of liver cancer in all subjects. Our results suggest that coffee consumption may reduce the risk of liver cancer regardless of HCV and HBV infection status, whereas green tea may not reduce this risk
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. mnminoue@ncc.go.jp
authors.forename: Manami
authors.initials: M
authors.lastname: Inoue
authors.forename: Norie
authors.initials: N
authors.lastname: Kurahashi
authors.forename: Motoki
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Taichi
authors.initials: T
authors.lastname: Shimazu
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D003069:Coffee; D015331:Cohort Studies; D006509:Hepatitis B; D006526:Hepatitis C; D006525:Hepatitis, Viral, Human / Q000821:virology*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000453:epidemiology* / Q000821:virology*; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013662:Tea
chemical_list: D003069:Coffee; D013662:Tea