Background:Night shift work, exposure to light at night (ALAN) and circadian disruption may increase the risk of hormone-dependent cancers.Objectives:We evaluated the association of exposure to ALAN during sleeping time with breast and prostate cancer in a population based multicase–control study (MCC-Spain), among subjects who had never worked at night. We evaluated chronotype, a characteristic that may relate to adaptation to light at night.Methods:We enrolled 1,219 breast cancer cases, 1,385 female controls, 623 prostate cancer cases, and 879 male controls from 11 Spanish regions in 2008–2013. Indoor ALAN information was obtained through questionnaires. Outdoor ALAN was analyzed using images from the International Space Station (ISS) available for Barcelona and Madrid for 2012–2013, including data of remotely sensed upward light intensity and blue light spectrum information for each geocoded longest residence of each MCC-Spain subject.Results:Among Barcelona and Madrid participants with information on both indoor and outdoor ALAN, exposure to outdoor ALAN in the blue light spectrum was associated with breast cancer [adjusted odds ratio (OR) for highest vs. lowest tertile, OR=1.47; 95% CI: 1.00, 2.17] and prostate cancer (OR=2.05; 95% CI: 1.38, 3.03). In contrast, those exposed to the highest versus lowest intensity of outdoor ALAN were more likely to be controls than cases, particularly for prostate cancer. Compared with those who reported sleeping in total darkness, men who slept in “quite illuminated” bedrooms had a higher risk of prostate cancer (OR=2.79; 95% CI: 1.55, 5.04), whereas women had a slightly lower risk of breast cancer (OR=0.77; 95% CI: 0.39, 1.51).Conclusion:Both prostate and breast cancer were associated with high estimated exposure to outdoor ALAN in the blue-enriched light spectrum. https://doi.org/10.1289/EHP1837

Because the prognosis of giant cell arteritis (GCA) is related to the development of ischemic complications, we sought to assess the possible influence of traditional risk factors of atherosclerosis in the development of severe ischemic complications of GCA. We conducted a retrospective study of patients with biopsy-proven GCA diagnosed from 1981 to 2001 at the single hospital for a well-defined population of almost 250,000 people. Patients were considered to have severe ischemic manifestations if they suffered visual manifestations, cerebrovascular accidents, jaw claudication, or signs of occlusive changes in large arteries of the extremities. Patients were assessed for the presence of hypercholesterolemia, hypertension, diabetes mellitus, and heavy smoking at the time of GCA diagnosis. The presence of traditional risk factors of atherosclerosis at the time of GCA diagnosis in this series of 210 patients increased significantly the risk of developing at least 1 of the severe ischemic complications (odds ratio [OR], 1.79; 95% confidence intervals [CI], 1.03-3.11; p = 0.04). Patients with traditional atherosclerosis risk factors had fever less commonly than the rest of GCA patients (5.2% vs. 16.0%; p = 0.01). GCA patients with hypertension exhibited a significantly increased risk of developing severe ischemic complications (OR, 1.80; 95% CI, 1.00-3.25; p = 0.05). The current study suggests that the presence of atherosclerosis risk factors at the time of diagnosis of GCA may influence the development of severe ischemic manifestations of the disease.

The relationship between vitamin D and breast cancer is still controversial. The present meta-analysis examines the effects of the 25(OH)D, 1,25(OH)2D and vitamin D intake on breast cancer risk. For this purpose, a PubMed, Scopus and Web of Science-databases search was conducted including all papers published with the keywords “breast cancer” and “vitamin D” with at least one reported relative risk (RR) or odds ratio (OR). In total sixty eight studies published between 1998 and 2018 were analyzed. Information about type of study, hormonal receptors and menopausal status was retrieved. Pooled OR or RR were estimated by weighting individual OR/RR by the inverse of their variance Our study showed a protective effect between 25 (OH) D and breast cancer in both cohort studies (RR = 0.85, 95%CI:0.74–0.98) and case-control studies (OR = 0.65, 95%CI: 0.56–0.76). However, analyzing by menopausal status, the protective vitamin D – breast cancer association persisted only in the premenopausal group (OR = 0.67, 95%CI: 0.49–0.92) when restricting the analysis to nested case-control studies. No significant association was found for vitamin D intake or 1,25(OH)2D. Conclusion: This systematic review suggests a protective relationship between circulating vitamin D (measured as 25(OH) D) and breast cancer development in premenopausal women.