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. 2020 Sep;31(5):718-727.
doi: 10.1097/EDE.0000000000001226.

Association Between Outdoor Light-at-night Exposure and Colorectal Cancer in Spain

Ariadna Garcia-Saenz  1   2   3   4   5   6   7   8   9   10   11   12   13 , Alejandro Sánchez de Miguel  1   2   3   4   5   6   7   8   9   10   11   12   13 , Ana Espinosa  8 , Laura Costas  2   9 , Nuria Aragonés  2   11 , Cathryn Tonne  1   2   3   4   5   6   7   8   9   10   11   12   13 , Victor Moreno  2   9   10   12 , Beatriz Pérez-Gómez  2   13 , Antonia Valentin  1   3   8 , Marina Pollán  2   13 , Gemma Castaño-Vinyals  8 , Martin Aubé  6 , Manolis Kogevinas  8
Affiliations

Association Between Outdoor Light-at-night Exposure and Colorectal Cancer in Spain

Ariadna Garcia-Saenz et al. Epidemiology. 2020 Sep.

Abstract

Background: Night-shift work, exposure to artificial light-at-night (ALAN) and particularly blue light spectrum, and the consequent circadian disruption may increase the risk of breast and prostate cancer. Colorectal cancer risk may also be increased among night-shift workers. We investigated the association between exposure to ALAN according to light spectrum and colorectal cancer among subjects who had never worked at night in a general population case-control study in Spain.

Methods: We examined information on 661 incident histologically verified colorectal cancer cases and 1,322 controls from Barcelona and Madrid, 2007-2013. Outdoor ALAN exposure was based on images from the International Space Station (ISS) including data on remotely sensed upward light intensity. We derived adjusted odds ratio (OR) estimates and confidence intervals (CI) for visual light, blue light, and spectral sensitivities of the five human photopigments assigned to participant's geocoded longest residence.

Results: Exposure to blue light spectrum was positively associated with colorectal cancer (OR = 1.6; 95% CI: 1.2-2.2; highest vs. lowest tertile). ORs were similar (OR = 1.7; 95% CI: 1.3-2.3) when further adjusting for area socioeconomic status, diet patterns, smoking, sleep, and family history. We observed no association for outdoor visual light (full spectrum) (OR = 1.0; 95% CI, 0.7-1.2; highest vs. lowest tertile). Analysis of the five photopigments gave similar results with increased risks for shorter wavelengths overlapping with the blue spectrum and no association for longer wavelengths.

Conclusions: Outdoor blue light spectrum exposure that is increasingly prevalent in recent years may be associated with colorectal cancer risk. See video abstract: http://links.lww.com/EDE/B708.

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References

    1. Ferlay J, Soerjomataram I, Dikshit R, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer. 2015;136:E359–E386.
    1. Walasa WM, Carey RN, Si S, et al. Association between shiftwork and the risk of colorectal cancer in females: a population-based case-control study. Occup Environ Med. 2018;75:344–350.
    1. World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR). Food, nutrition, physical activity, and the prevention of cancer: a global perspective. World Cancer Res Fund Int. 2007;517.
    1. Romaguera D, Gracia-Lavedan E, Molinuevo A, et al. Adherence to nutrition-based cancer prevention guidelines and breast, prostate and colorectal cancer risk in the MCC-Spain case-control study. Int J Cancer. 2017;141:83–93.
    1. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Painting, firefighting, and shiftwork. IARC Monogr Eval Carcinog Risks Hum. 2010;98:9–764.