title: Industry-based retrospective cohort study of the risk of prostate cancer among rotating-shift workers.
abstract: OBJECTIVE
  The risk of prostate cancer among shift workers was examined in the present industry-based retrospective cohort study.
  
  
  METHODS
  The study was established based on a health-care database from a Japanese manufacturing corporation. Work schedules of 4995 male workers (mean age = 55.5 years) were followed up retrospectively; mean follow-up period = 25.0 years. Of the subjects, 4168 had previously undertaken only daytime work (daytime workers), whereas 827 had undertaken rotating three-shift work for >80% of their career (shift workers). All subjects had undergone prostate-specific antigen (PSA) testing. Prostate cancer incidence data were obtained from the health insurance records of 13 daytime and four shift workers. Multivariate logistic regression was used to estimate the relative risk of prostate cancer for the two groups with adjustments for age, body mass index, alcohol intake, smoking, exercise and marital status.
  
  
  RESULTS
  Compared with daytime workers, shift workers showed a non-significant increase in the risk of prostate cancer (odds ratio = 1.79; 95% confidence interval = 0.57, 5.68; P-value = 0.32).
  
  
  CONCLUSIONS
  Some increase in the risk of prostate cancer for shift workers was observed, although the result was not statistically significant as a result of the small number of cases. To identify the prostate cancer risk among shift workers, longer-term follow up, including the period after retirement, is required.
authors.affiliation: Department of Public Health, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. kubo@med.uoeh-u.ac.jp
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kubo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Oyama
authors.forename: Takehiro
authors.initials: T
authors.lastname: Nakamura
authors.forename: Masamizu
authors.initials: M
authors.lastname: Kunimoto
authors.forename: Koji
authors.initials: K
authors.lastname: Kadowaki
authors.forename: Hajime
authors.initials: H
authors.lastname: Otomo
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujino
authors.forename: Naohiro
authors.initials: N
authors.lastname: Fujimoto
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Shinya
authors.initials: S
authors.lastname: Matsuda
mesh_terms: D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D015331:Cohort Studies; D016208:Databases, Factual; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016272:Occupational Health / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014940:Work Schedule Tolerance