FTA:

A new study reports that sleep efficiency, a ratio of time asleep to time spent in bed, is predictive of survival time for women with advanced breast cancer. According to the authors, this is the first study to demonstrate the long-term detrimental effects of objectively quantified sleep on survival in women with advanced cancer. Although the mechanism of the relationship between sleep quality and advanced breast cancer survival is unclear, they suggested that sleep disruption may lead to diminished immune function or impaired hormonal stress responses that are more directly responsible for the decrease in survival.