title: Obesity and risk of cancer in Japan.
abstract: We conducted a population-based prospective cohort study in Japan to examine the relationship between body mass index (BMI) and the risk of incidence of any cancer and of cancer at individual sites. Body mass index was calculated from self-administered body weight and height at baseline. Relative risks (RR) and 95% confidence intervals (CI) were calculated in multivariate proportional-hazards models. Among 27,539 persons (15,054 women and 12,485 men) aged 40 years or older who were free of cancer at enrollment in 1984, 1,672 (668 women and 1,004 men) developed cancer during 9 years of follow-up. In women, after adjustment for potential confounders, the RR of all cancers associated with different BMI, relative to a BMI of 18.5-24.9, were 1.04 (95% CI = 0.85-1.27) for BMI = 25.0-27.4, 1.29 (1.00-1.68) for BMI = 27.5-29.9 and 1.47 (1.06-2.05) for BMI >/=30.0 (p for trend = 0.007). Higher BMI was also significantly associated with higher risk of cancers of the colorectum, breast (postmenopausal), endometrium and gallbladder in women. In men, we observed significantly increased all-cancer risk among only never-smokers. Overweight and obesity could account for 4.5% (all subjects) or 6.2% (never-smokers) of the risk of any cancer in women and -0.2% (all subjects) or 3.7% (never-smokers) in men. The value for women was within the range among women reported from Western populations (3.2%-8.8%). Our data demonstrate that excess weight is a major cancer risk among Japanese women.
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Miyagi, Japan. kuriyama-thk@umin.ac.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kuriyama
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tsubono
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hozawa
authors.forename: Taichi
authors.initials: T
authors.lastname: Shimazu
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Koizumi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Kaori
authors.initials: K
authors.lastname: Ohmori
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nishino
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D009765:Obesity / Q000150:complications* / Q000453:epidemiology*; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D012737:Sex Factors