Cancer Epidemiol

Background:Outdoor artificial light at night (ALAN) has been implicated in a growing number of adverse health outcomes. ALAN is believed to disrupt circadian rhythms and has been associated with increased inflammation, one of the hallmarks of cancer. We examined the association between outdoor ALAN and a cancer strongly associated with autoimmune and inflammatory conditions, non-Hodgkin lymphoma (NHL), in the prospective California Teachers Study cohort.Methods:Outdoor ALAN was assigned to participant addresses at study baseline (1995-96) through use of the New World Atlas of Artificial Night Sky Brightness. Among 105,937 women followed from 1995-2015, linkage to the California Cancer Registry identified 873 incident cases of NHL. Age-stratified Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (95%CI) for overall NHL and the most common NHL subtypes; diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Multivariate analyses adjusted for previously reported subtype specific covariates (e.g. body mass index (BMI) for DLBCL).Results:Compared to the lowest quintile, participants residing in the highest quintile of outdoor ALAN at baseline were more likely to develop NHL (HR=1.32, 95%CI=1.07-1.63), and, in particular, DLBCL (HR=1.87, 95%CI=1.16-3.02). The elevated risk for DLBCL remained statistically significant after adjusting for age, race/ethnicity, BMI, and socioeconomic status (DLBCL:HR=1.87, 95%CI=1.16-3.02, NHL:HR=1.32, 95%CI=1.07-1.63). There was no association between ALAN and FL or CLL/SLL.Conclusion:DLBCL risk was elevated among women residing in neighborhoods with greater outdoor ALAN. Future research in circadian disruption and DLBCL may clarify potential biological processes implicated in this association.HHSN261201800032C/CA/NCI NIH HHS/United StatesHHSN261201800009C/CA/NCI NIH HHS/United StatesNU58DP006344/DP/NCCDPHP CDC HHS/United StatesHHSN261201800015I/CA/NCI NIH HHS/United StatesHHSN261201800032I/CA/NCI NIH HHS/United StatesP30 CA033572/CA/NCI NIH HHS/United StatesHHSN261201800015C/CA/NCI NIH HHS/United StatesHHSN261201800009I/CA/NCI NIH HHS/United StatesU01 CA199277/CA/NCI NIH HHS/United StatesUM1 CA164917/CA/NCI NIH HHS/United StatesP30 CA023100/CA/NCI NIH HHS/United StatesR01 CA077398/CA/NCI NIH HHS/United States2021-12-01T00:00:00Z33002844PMC77105548772vault:3623