Assessing the role of sleep in reducing risk and improving outcomes for breast cancer

Summary

There is an extensive literature surrounding the impact disturbance to the body clock has on breast cancer risk, although much of the evidence comes from studies on animal rather than humans. While previous human studies have focused on the potential carcinogenic effect of night shift work, we have recently investigated the impact of sleep on breast cancer risk using data from women enrolled in large population-based studies. We found that women who woke earlier and who slept longer seemed to be less likely to get breast cancer. However, we do not know why this is and further work to understanding potential mechanisms is required. In addition, looking at the influence of sleep preference (e.g. morning/evening preference) vs. actual sleep patterns requires further exploration. Understanding the timing of risk is also necessary to assess whether sleep patterns are important at certain times in the life-course so that interventions can be developed to support that. Related to this is the need to evaluate whether sleep has an influence on outcomes such as survival, recurrence and treatment success among women diagnosed with breast cancer. Finally, an assessment of potential interventions to improve sleep among women diagnosed with, or at high risk of, breast cancer is needed, including evaluating the perceived importance of sleep and acceptability of interventions within a clinical setting. There is an extensive literature surrounding the impact disturbance to the body clock has on breast cancer risk, although much of the evidence comes from studies on animal rather than humans. While previous human studies have focused on the potential carcinogenic effect of night shift work, we have recently investigated the impact of sleep on breast cancer risk using data from women enrolled in large population-based studies. We found that women who woke earlier and who slept longer seemed to be less likely to get breast cancer. However, we do not know why this is and further work to understanding potential mechanisms is required. In addition, looking at the influence of sleep preference (e.g. morning/evening preference) vs. actual sleep patterns requires further exploration. Understanding the timing of risk is also necessary to assess whether sleep patterns are important at certain times in the life-course so that interventions can be developed to support that. Related to this is the need to evaluate whether sleep has an influence on outcomes such as survival, recurrence and treatment success among women diagnosed with breast cancer. Finally, an assessment of potential interventions to improve sleep among women diagnosed with, or at high risk of, breast cancer is needed, including evaluating the perceived importance of sleep and acceptability of interventions within a clinical setting.