title: Prospective cohort study of the risk of prostate cancer among rotating-shift workers: findings from the Japan collaborative cohort study.
abstract: Shift workers have been reported to have an increased risk of some cancers. However, the risk of prostate cancer in shift workers is not known to have been examined previously. This study prospectively examined the association between shift work and risk of prostate cancer incidence among 14,052 working men in Japan enrolled in a large-scale prospective cohort. A baseline survey was conducted between 1988 and 1990. Subjects were asked to indicate the most regular work schedule they had undertaken previously: day work, rotating-shift work, or fixed-night work. During 111,974 person-years, 31 cases of prostate cancer were recorded. The Cox proportional hazards model was used to estimate the risk, with adjustments for age, family history of prostate cancer, study area surveyed, body mass index, smoking, alcohol drinking, job type, physical activity at work, workplace, perceived stress, educational level, and marriage status. Compared with day workers, rotating-shift workers were significantly at risk for prostate cancer (relative risk = 3.0, 95% confidence interval: 1.2, 7.7), whereas fixed-night work was associated with a small and nonsignificant increase in risk. This report is the first known to reveal a significant relation between rotating-shift work and prostate cancer.
authors.affiliation: Department of Clinical Epidemiology, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kubo
authors.forename: Kotaro
authors.initials: K
authors.lastname: Ozasa
authors.forename: Kazuya
authors.initials: K
authors.lastname: Mikami
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujino
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Tsuneharu
authors.initials: T
authors.lastname: Miki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakao
authors.forename: Kyohei
authors.initials: K
authors.lastname: Hayashi
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Mori
authors.forename: Masakazu
authors.initials: M
authors.lastname: Washio
authors.forename: Fumio
authors.initials: F
authors.lastname: Sakauchi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
authors.forename: Takesumi
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Akiko
authors.initials: A
authors.lastname: Tamakoshi
mesh_terms: D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D015331:Cohort Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D014940:Work Schedule Tolerance