AR and Familial prostate cancer: Altered light exposure dysregulates circadian rhythms, and it is thought that the biological effects of circadian rhythm disruption may affect androgen expression, androgen receptors, cyclin D1, cell proliferation, apoptosis, and repair.85 In 1 case study obtained from the GLOBOCAN 2002 database on light-at-night and prostate cancer, the increase in light-at-night from minimal average exposure to average exposure corresponded to an increase in prostate cancer age-standardized rate by 30.5%.