ArticleCancer causes & control : CCC2024
Prospective analysis of sleep characteristics, chronotype, and risk of breast cancer in the california teachers study.
Article in Cancer causes & control : CCC, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 2 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
5 citing papers in PubMed, 2 syntheses or guidelines pooled it, 9 citations in OpenAlex.
- Pooled it
- Sleep Traits to the Risk of Breast Cancer Disease Incidence, Adverse Progression and Mortality: Evidence From a Global Systematic Review and Meta-Analysis.International journal of public health · 2025Pooled it
- Sleep midpoint, social jetlag, and cancer risk in the Cancer Prevention Study-3.Cancer causes & control : CCC · 2026Article
- Night shift work and breast cancer risk - 2023 update of epidemiologic evidence.Journal of the National Cancer Center · 2025Review
- Chronotype and Cancer: Emerging Relation Between Chrononutrition and Oncology from Human Studies.Nutrients · 2025Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 3 institutions in 1 country.
Funding
Abstract
purposePoor sleep quality and evening chronotype were associated with increased risk of breast cancer in a previous retrospective study in the California Teachers Study (CTS). The present analysis examines these sleep factors prospectively in the same cohort of women.
methodsFrom the CTS, we included 1,085 incident breast cancer cases and 38,470 cancer-free participants from 2012 through 2019. We calculated time at risk and used Cox proportional hazards regression models to estimate the hazard ratios (HRs) and control for risk factors such as age, race, body mass index, family history of breast cancer, and reproductive history. The sleep factors examined were quality, latency, duration, disturbance, and sleep medication use, based on a shortened version of the Pittsburgh Sleep Quality Index, as well as chronotype (preference for morning or evening activity). This analysis was limited to women who were post-menopausal at the time they answered these sleep-related questions.
resultsMeasures of sleep quality did not appear to be associated with subsequent breast cancer risk. The HR for evening chronotypes compared to morning chronotypes was somewhat elevated (HR 1.19, 95% CI 1.04, 1.36).
conclusionWhile the measures of sleep quality and duration were not associated with post-menopausal breast cancer risk in this prospective analysis, the modestly elevated risk observed for evening chronotypes was consistent with the prior retrospective analysis.
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.