Association between outdoor light at night and breast cancer risk among postmenopausal women

breast cancer cell
A breast cancer cell, photographed by a scanning electron microscope. Credit: Bruce Wetzel and Harry Schaefer, National Cancer Institute, National Institutes of Health

Outdoor light at night was linked to a higher risk of breast cancer in a study published in the International Journal of Cancer.

For the study, investigators analyzed residential outdoor light at night estimated from in 1996 and assessed rates of over 16 years of follow-up in 186,981 .

Compared with the lowest level of exposure to outdoor light at night, the highest exposure was associated with a 10% higher risk of developing breast cancer during follow-up, after controlling for confounding factors.

"The small number of studies to investigate this question have often relied on subjective exposure data and yielded inconsistent results. We utilized an objective exposure measure—estimated outdoor light at night from satellite data," said senior author Rena Jones, Ph.D., MS, of the National Cancer Institute, part of the National Institutes of Health. "It will be important for future studies to accurately measure light at night exposure for individuals using a combination of objective measures, carefully designed questionnaires, and personal measurement devices."

More information: Qian Xiao et al, Outdoor light at night and postmenopausal breast cancer risk in the NIH‐AARP diet and health study, International Journal of Cancer (2020). DOI: 10.1002/ijc.33016

Journal information: International Journal of Cancer
Provided by Wiley
Citation: Association between outdoor light at night and breast cancer risk among postmenopausal women (2020, June 3) retrieved 30 May 2024 from
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Outdoor light at night linked with increased breast cancer risk in women


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