Breast cancer risk and sleep

Researchers at the Western Australian Institute for Medical Research (WAIMR) investigated the relationship between self-reported sleep quality and breast cancer among women aged 18 to 80.

Participants included 1200 women with invasive breast cancer and nearly 1800 randomly selected controls. 

They completed a postal questionnaire covering their demographic, reproductive history and lifestyle as well as sleep duration and quality.

The role of circadian rhythm was also assessed. 

No association was found among sleep duration on workdays or non-workdays, sleep quality and breast cancer risk. Author Jennifer Girschik (PhD) said the results were reassuring.

“Sleep is often something people are very concerned about,” she said.

“We all know when we have had a bad night’s sleep how debilitating that can be.

“[However] sleep disturbance, short duration or having poor quality