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Cited by 930Circadian rhythm and melatoninSleep and Work-Related FatigueImpact of Light on Environment and Health

Night Shift Work, Light at Night, and Risk of Breast Cancer

Davis, S., Mirick, D. K., Stevens, R. G.·2001·JNCI Journal of the National Cancer Institute
DOI 10.1093/jnci/93.20.1557
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Abstract

BACKGROUND: Exposure to light at night may increase the risk of breast cancer by suppressing the normal nocturnal production of melatonin by the pineal gland, which, in turn, could increase the release of estrogen by the ovaries. This study investigated whether such exposure is associated with an increased risk of breast cancer in women. METHODS: Case patients (n = 813), aged 20-74 years, were diagnosed from November 1992 through March 1995; control subjects (n = 793) were identified by random-digit dialing and were frequency matched according to 5-year age groups. An in-person interview was used to gather information on sleep habits and bedroom lighting environment in the 10 years before diagnosis and lifetime occupational history. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by use of conditional logistic regression, with adjustment for other potential risk factors. RESULTS: Breast cancer risk was increased among subjects who frequently did not sleep during the period of the night when melatonin levels are typically at their highest (OR = 1.14 for each night per week; 95% CI = 1.01 to 1.28). Risk did not increase with interrupted sleep accompanied by turning on a light. There was an indication of increased risk among subjects with the brightest bedrooms. Graveyard shiftwork was associated with increased breast cancer risk (OR = 1.6; 95% CI = 1.0 to 2.5), with a trend of increased risk with increasing years and with more hours per week of graveyard shiftwork (P =.02, Wald chi-squared test). CONCLUSION: The results of this study provide evidence that indicators of exposure to light at night may be associated with the risk of developing breast cancer.

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Crossref · 10.1093/jnci/93.20.1557

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  • A significant association between breast cancer risk and exposure to nonoccupational light during the night at home is found for women who did not sleep during the period of melatonin level peaks, or who frequently turned on the light during the night.

    “A significant association between breast cancer risk and exposure to nonoccupational light during the night at home is found for women who did not sleep during the period of melatonin level peaks, or who frequently turned on the light during the night 107, 108, 109.”

    From The inner clock-Blue light sets the human rhythm (2019) · cites this paper as [107]

  • Increased breast cancer risk is also correlated with increasing bedroom light levels.

    “Similarly, increased breast cancer risk is also correlated with increasing bedroom light levels.”

    From The inner clock-Blue light sets the human rhythm (2019) · cites this paper as [107]

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Authors
Davis, S., Mirick, D. K., & Stevens, R. G.
Affiliations
Fred Hutch Cancer Center (US)
Corresponding author
Davis, S.
Venue
JNCI Journal of the National Cancer Institute
Publisher
Oxford University Press (OUP)
Published
2001-10-17
Volume
93
Issue
20
Pages
1557-1562
ISSN
  • 0027-8874 (ISSN-L)
  • 1460-2105
DOI
10.1093/jnci/93.20.1557
OpenAlex
W2156539373
Cited by
930
References
29
Citations by year
2026: 10 · 2025: 19 · 2024: 23 · 2023: 30 · 2022: 28 · 2021: 32 · 2020: 39 · 2019: 37 · 2018: 34 · 2017: 60 · 2016: 35 · 2015: 48 · 2014: 48 · 2013: 54 · 2012: 52
FWCI
9.03
Type
journal article
Language
en
Open access
closed
Locations
  • JNCI Journal of the National Cancer Institute (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • National Institutes of Health (5r01ca055844-04)
  • National Cancer Institute (R01-CA55844)
Topics
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
  • Physical Sciences › Environmental Science › Global and Planetary Change › Impact of Light on Environment and Health
Keywords
breast cancer, light at night, night shift work, graveyard shift, melatonin suppression, pineal gland, bedroom lighting, sleep habits, occupational exposure, estrogen
MeSH terms
Adult, Aged, Breast Neoplasms, Circadian Rhythm, Electromagnetic Fields, Environmental Exposure, Female, Habits, Humans, Light, Lighting, Melatonin, Middle Aged, Occupations, Pineal Gland, Residence Characteristics, Risk Factors, Secretory Rate, Sleep, Work Schedule Tolerance, Occupational Exposure

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