Table 1.

Characteristics of studies on night shift work and prostate cancer risk

Author, countryStudy design, populationNumber of prostate cancerData collectionAdjusted covariablesExposure definitionRisk estimate (95% CI)
Parent et al. (2012), Québec, CanadaPopulation-based case-control study400 cases512 controlsFace-to-face interviewAge, ancestry, educational level, family income, smoking, alcohol, BMI, farming, occupational physical activityShift work Night work: working between 1:00 AM and 2:00 AM for at least 6 monthsOR = 2.77 (1.96–3.92)
Gaptsur et al. (2014), United StatesCancer Prevention Study–II cohort American Cancer Society volunteers friends, neighbors, and relatives4,974 casesSelf-administered questionnaireAge, race, education, BMI, smoking history, family history of prostate cancer, and frequent or painful urinationFixed night shift = 9:00 PM to 12:00 PMRotating shiftRR = 0.72 (0.44–1.18)RR = 1.08 (0.95–1.22)
Yong et al. (2014), GermanyCohort Study of male chemical production workers337 casesPersonnel files Occupational health recordsAge, smoking, professional status, and duration of employmentShift patterns = "3 × 12 hours" or "4 × 12 hours" in which workers alternate day shifts, night shifts, and free periodsHR = 0.93 (0.71–1.21)
Papantoniou et al. (2015), SpainPopulation-based case-control study1,095 cases 1,338 controlsFace-to-face and phone interviewsAge, family history of prostate cancer, leisure, time physical activity, smoking status, past sun exposure, meat consumption, center, and educational levelNight shift = partly or entirely between 00:00 AM and 06:00 AM at least three times per monthOR = 1.14 (0.94–1.37)
Dickerman et al. (2016), FinlandProspective cohort study of Finnish same-sex twin pairs602 casesMailed questionnaireAge, education, BMI, physical activity, social class, social class, smoking status, alcohol use, snoring, zygosity, chronotypeLast or current work Fixed night Rotating shiftHR = 0.50 (0.10–1.90) HR = 1.00 (0.70–1.20)
Rao et al. (2015)Meta-analysis9,669 casesNight shift workRR = 1.24 (1.05–1.46)

Abbreviation: BMI, body mass index.