Outdoor Light at Night and Breast Cancer Incidence in the Nurses' Health Study II.

ABSTRACT:

Background

Animal and epidemiologic studies suggest that exposure to light at night (LAN) may disrupt circadian patterns and decrease nocturnal secretion of melatonin, which may disturb estrogen regulation, leading to increased breast cancer risk.

Objectives

We examined the association between residential outdoor LAN and breast cancer incidence using data from the nationwide U.S.-based Nurses' Health Study II cohort.

Methods

We followed 109,672 women from 1989 through 2013. Cumulative LAN exposure was estimated using time-varying satellite data for a composite of persistent nighttime illumination at ∼1 km² scale for each residence during follow-up. Incident invasive breast cancer cases were confirmed by medical record review. We used Cox proportional hazard

SUBMITTER: James P 

PROVIDER: S-EPMC5783660 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature