- In women diagnosed with breast cancer, poor sleep quality or short duration are associated with breast cancer aggressiveness.
- Results vary by race/ethnicity.
- The findings suggest that improving sleep duration and quality might be associated with less aggressive tumor characteristics.
- Observational study of 4171 white women and 235 black women diagnosed with incident breast cancer in the Women's Health Initiative (WHI; 1994-2013).
- Baseline sleep duration and quality were compared with tumor grade, stage, hormone receptor status, and human epidermal growth factor receptor 2 status using logistic regression.
- 3 measures of sleep quality were studied: very sound or restful sleep, average sleep, and restless or very restless sleep.
- Funding: US National Institutes of Health.