ArticleInternational journal of epidemiology2009
Light-at-night, circadian disruption and breast cancer: assessment of existing evidence.
Article in International journal of epidemiology, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 110 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
110 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Light at night exposure and risk of breast cancer: a meta-analysis of observational studies.Frontiers in public health · 2023Pooled it
- Pooled it
- Research recommendations for selected IARC-classified agents.Environmental health perspectives · 2010Pooled it
- Decrease in fMRI brain activation during working memory performed after sleeping under 10 lux light.Scientific reports · 2016Trial
- Individual variations in serum melatonin levels through time: implications for epidemiologic studies.PloS one · 2013Trial
- Occupational Exposure to Blue Light Emitted from Neonatal Phototherapy Devices Alters the Sleep Quality of NICU Nurses.Journal of biomedical physics & engineering · 2026Article
- The impact of working conditions on breast cancer outcomes: a study protocol for a population-based cohort study using UK Biobank data.BMJ open · 2025Article
- Childhood Myopia Part II: Treatment Mechanisms, Emerging Options, and Considerations.Investigative ophthalmology & visual science · 2025Review
- A narrative review of sleep and breast cancer: from epidemiology to mechanisms.Cancer causes & control : CCC · 2025Review
- Melatonin and Breast Cancer: A Review Article.Chonnam medical journal · 2025Review
- Review
- Associations of light exposure patterns with sleep among Dutch children: The ABCD cohort study.Journal of sleep research · 2024Article
- The Influence of Circadian Rhythms on DNA Damage Repair in Skin Photoaging.International journal of molecular sciences · 2024Review
- Article
- A pilot study of light exposure as a countermeasure for menstrual phase-dependent neurobehavioral performance impairment in women.Sleep health · 2024Article
- Article
- Therapeutic Potential of Melatonin Counteracting Chemotherapy-Induced Toxicity in Breast Cancer Patients: A Systematic Review.Pharmaceutics · 2023Review
- Effects of workload and job stress on the shift work disorders among nurses: PLS SEM modeling.European journal of translational myology · 2022Article
- Circadian Rhythm Disruption as a Contributor to Racial Disparities in Prostate Cancer.Cancers · 2022Review
- Melatonin and cancer suppression: insights into its effects on DNA methylation.Cellular & molecular biology letters · 2022Article
50 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
1 author.
Funding
Abstract
backgroundBreast cancer incidence is increasing globally for largely unknown reasons. The possibility that a portion of the breast cancer burden might be explained by the introduction and increasing use of electricity to light the night was suggested >20 years ago.
methodsThe theory is based on nocturnal light-induced disruption of circadian rhythms, notably reduction of melatonin synthesis. It has formed the basis for a series of predictions including that non-day shift work would increase risk, blind women would be at lower risk, long sleep duration would lower risk and community nighttime light level would co-distribute with breast cancer incidence on the population level.
resultsAccumulation of epidemiological evidence has accelerated in recent years, reflected in an International Agency for Research on Cancer (IARC) classification of shift work as a probable human carcinogen (2A). There is also a strong rodent model in support of the light-at-night (LAN) idea.
conclusionIf a consensus eventually emerges that LAN does increase risk, then the mechanisms for the effect are important to elucidate for intervention and mitigation. The basic understanding of phototransduction for the circadian system, and of the molecular genetics of circadian rhythm generation are both advancing rapidly, and will provide for the development of lighting technologies at home and at work that minimize circadian disruption, while maintaining visual efficiency and aesthetics. In the interim, there are strategies now available to reduce the potential for circadian disruption, which include extending the daily dark period, appreciate nocturnal awakening in the dark, using dim red light for nighttime necessities, and unless recommended by a physician, not taking melatonin tablets.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.