Oncotype DX is a widely utilized test to guide treatment in early stage breast cancer by predicting likelihood of recurrence.
Researchers found that women who reported six hours or less of sleep per night on average before breast cancer diagnosis had increased Oncotype DX tumor recurrence scores.
“This is the first study to suggest that women who routinely sleep fewer hours may develop more aggressive breast cancers compared with women who sleep longer hours,” Dr. Thompson said.
“We found a strong correlation between fewer hours of sleep per night and worse recurrence scores, specifically in post-menopausal breast cancer patients.
This suggests that lack of sufficient sleep may cause more aggressive tumors, but more research will need to be done to verify this finding and understand the causes of this association,” she said.
The researchers also revealed that the correlation of sleep duration and recurrence score was strong in post-menopausal women. The data suggested that sleep might affect carcinogenic pathway(s) specifically involved in the development of post-menopausal breast cancer.
