Night-Shift Work and Breast Cancer Risk in a Cohort of Chinese Women
Open accessAbstract
Shift work involving disruption of circadian rhythms has been classified as a probable cause of human cancer by the International Agency for Research on Cancer, based on limited epidemiologic evidence and abundant experimental evidence. The authors investigated this association in a population-based prospective cohort study of Chinese women. At baseline (1996-2000), information on lifetime occupational history was obtained from 73,049 women. Lifetime night-shift exposure indices were created using a job exposure matrix. During 2002-2004, self-reported data on frequency and duration of night-shift work were collected. Hazard ratios and 95% confidence intervals, adjusted for major breast cancer risk factors, were calculated. During follow-up through 2007, 717 incident cases of breast cancer were diagnosed. Breast cancer risk was not associated with ever working the night shift on the basis of the job exposure matrix (adjusted hazard ratio = 1.0, 95% confidence interval: 0.9, 1.2) or self-reported history of night-shift work (adjusted hazard ratio = 0.9, 95% confidence interval: 0.7, 1.1). Risk was also not associated with frequency, duration, or cumulative amount of night-shift work. There were no indications of effect modification. The lack of an association between night-shift work and breast cancer adds to the inconsistent epidemiologic evidence. It may be premature to consider shift work a cause of cancer.
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A number of studies found no association between cancer and shift work.
“However, a number of studies have found no association between cancer and shift work [64,65,66,67].”
From Shift Work: Disrupted Circadian Rhythms and Sleep—Implications for Health and Well-being (2017) · cites this paper as [66]
Observational studies consistently suggest positive associations of night shift work with cardiovascular disease and cancer risk.
“Observational studies consistently suggest positive associations of night shift work and cardiovascular disease (CVD)2 and cancer risk.3-18”
From Total and Cause-Specific Mortality of U.S. Nurses Working Rotating Night Shifts (2015) · cites this paper as [11]
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References 23 · Cited by 160
Research works printed but not linked: 1
- Breast cancer on the night shift [editorial]. Lancet. 2009; 373(9669):1054.
- Authors
- Pronk, A., Ji, B. T., Shu, X. O., Xue, S., Yang, G., Li, H. L., Rothman, N., Gao, Y. T., Zheng, W., & Chow, W. H.
- Affiliations
- National Cancer Institute (US)
- National Institutes of Health (US)
- Vanderbilt University (US)
- Shanghai Cancer Institute (CN)
- Corresponding author
- Chow, W. H.
- Venue
- American Journal of Epidemiology
- Publisher
- Oxford University Press (OUP)
- Published
- 2010-04-07
- Volume
- 171
- Issue
- 9
- Pages
- 953-959
- ISSN
- 0002-9262 (ISSN-L)
- 1476-6256
- PMC
- PMC2877476
- OpenAlex
- W2114014633
- Cited by
- 160
- References
- 23
- Citations by year
- 2026: 1 · 2025: 3 · 2024: 3 · 2023: 5 · 2022: 1 · 2021: 7 · 2020: 10 · 2019: 6 · 2018: 9 · 2017: 15 · 2016: 9 · 2015: 11 · 2014: 15 · 2013: 29 · 2012: 19
- FWCI
- 27.05
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- American Journal of Epidemiology (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- TNO Repository (submittedVersion)
- Repository hosted by TU Delft Library (TU Delft) (submittedVersion)
- Data Archiving and Networked Services (DANS) (submittedVersion)
- Funders
- Vanderbilt University
- Vanderbilt-Ingram Cancer Center
- National Institutes of Health (N02 CP1101066)
- School of Medicine, Vanderbilt University
- National Cancer Institute (N02-CP-11010-66, R01 CA70867, R01CA070867)
- Division of Cancer Epidemiology and Genetics, National Cancer Institute
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
- Health Sciences › Medicine › Oncology › Cancer Risks and Factors
- Keywords
- night shift work, shift work, breast cancer risk, circadian rhythm disruption, occupational exposure, Chinese women, job-exposure matrix, cancer classification
- MeSH terms
- Adult, Aged, Breast Neoplasms, China, Circadian Rhythm, Female, Humans, Middle Aged, Personnel Staffing and Scheduling, Risk Factors, Socioeconomic Factors, Time Factors, Work Schedule Tolerance, Cohort Studies
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