Night shift work and breast cancer: a pooled analysis of population-based case–control studies with complete work history
MetadataShow full item record
This is a post-peer-review, pre-copyedit version of an article published in European Journal of Epidemiology. The final authenticated version is available online at: http://doi.org/10.1007/s10654-018-0368-x.
© 2018 Springer Science+Business Media B.V., part of Springer Nature
Night shift work has been suspected to increase breast cancer risk but epidemiological studies have been inconsistent due to heterogeneous assessment of exposure to night work. To overcome this limitation, we pooled data of five population-based case–control studies from Australia, Canada, France, Germany, and Spain into a single harmonized dataset using a common definition of night work including 6093 breast cancer cases and 6933 population controls. The odds ratio for breast cancer in women who ever worked at night for at least 3 h between midnight and 5 a.m. as compared to never night workers was 1.12 (95% CI 1.00–1.25). Among pre-menopausal women, this odds ratio was 1.26 [1.06–1.51], increasing to 1.36 [1.07–1.74] for night shifts = 10 h, 1.80 [1.20–2.71] for work = 3 nights/week, and 2.55 [1.03–6.30] for both duration of night work = 10 years and exposure intensity = 3 nights/week. Breast cancer risk in pre-menopausal women was higher in current or recent night workers (OR = 1.41 [1.06–1.88]) than in those who had stopped night work more than 2 years ago. Breast cancer in post-menopausal women was not associated with night work whatever the exposure metric. The increase in risk was restricted to ER+ tumors, particularly those who were both ER+ and HER2+ . These results support the hypothesis that night shift work increases the risk of breast cancer in pre-menopausal women, particularly those with high intensity and long duration of exposure. Risk difference between pre- and post-menopausal women deserves further scrutiny.
Showing items related by title, author, creator and subject.
Shift work that involves circadian disruption and breast cancer: a first application of chronobiological theory and the consequent challenges.Fritschi, Lin; Valérie Groß, J.; Wild, U.; Heyworth, J.; Glass, D.; Erren, T. (2017)Objectives: In 2007, the International Agency for Research on Cancer classified shift work involving circadian disruption (CD) as probably carcinogenic to humans. Circadian disruption could be conceptualised as the overlap ...
Self-reported shift work, recall bias, and belief about disease causation in a case-control study of breast cancerLizama, N.; Heyworth, J.; Thomson, Allyson; Slevin, Terry; Fritschi, Lin (2017)© 2017 Elsevier Ltd Background Recall bias is a potential source of misclassification in case-control studies. Studies have shown that the association between exposure and disease can differ according to participants’ ...
Considerations of circadian impact for defining 'shift work' in cancer studies: IARC Working Group ReportStevens, R.; Hansen, J.; Costa, G.; Haus, E.; Kauppinen, T.; Aronson, K.; Castaño-Vinyals, G.; Davis, S.; Frings-Dresen, M.; Fritschi, Lin; Kogevinas, M.; Kogi, K.; Lie, J.; Lowden, A.; Peplonska, B.; Pesch, B.; Pukkala, E.; Schernhammer, E.; Travis, R.; Vermeulen, R.; Zheng, T.; Cogliano, V.; Straif, K. (2011)Based on the idea that electric light at night might account for a portion of the high and rising risk of breast cancer worldwide, it was predicted long ago that women working a non-day shift would be at higher risk ...