Richmond, R. et. al.

Investigating causal relationships between sleep characteristics and risk of breast cancer: a Mendelian randomization study

Poster Presentation, 2018 National Cancer Research Institute Annual Conference.
https://www.biorxiv.org/content/10.1101/457572v1.

Multiple studies have examined the relationships between sleep cycles and breast cancer. This current study sought to find a connection between a particular sleep pattern – early rising – and breast cancer risk.

Specific genetic variants have been found that determine a person’s preference for morning (early birds) or nighttime (night owls) activity. The investigators looked at these variants among almost 10,000 women with breast cancer and over 170,000 women without the disease.

Analysis of the data found that women who preferred early morning rising had a reduced breast cancer risk compared to women who preferred late night activity. Early rising appeared to be protective against breast cancer.

This information adds to the awareness of sleep/wake cycles and breast cancer risk. While not definitive, the study does expand the knowledge of a possible relationship between these lifestyle habits and breast cancer. Further study is needed to determine if there are indeed direct, definitive connections.