“…Although a few studies reported no significant association between breast cancer and night work (O'Leary et al 2006, Pronk et al 2010, the majority of recent studies reported significant or borderline associations, with the strongest association found with long-term exposure to night work (Hansen 2001, Schernhammer et al 2001, Hansen & Lassen 2012, Hansen & Stevens 2012, Knutsson et al 2013, Menegaux et al 2013, Rabstein et al 2013, Akerstedt et al 2015, Papantoniou et al 2015. Meta-analysis studies have also reported a positive association between night work and breast cancer risk (Jia et al 2013) and that a positive dose-response gradient is observed for breast cancer with increased years of night shift and cumulative night work .…”