Night work and breast cancer risk defined by human epidermal growth factor receptor-2 (HER2) and hormone receptor
Emilie Cordina-Duverger1, Yves Koudou1, Thérèse Truong1
1a Université Paris-Saclay, Université Paris-Sud, CESP (Center for Research in Epidemiology and Population Health) , Inserm, Team Cancer-Environment, Villejuif , France.
Abstract:
Night work has been associated with risk of breast cancer but this association needs to be confirmed. Because breast cancer is an etiologically heterogeneous disease, we explored the association of night work with breast cancer subtypes defined by tumor status (positive of negative) for estrogen-receptor (ER), progesterone-receptor (PR) and human epidermal growth factor-receptor 2 (HER2). Using the data from a case-control study in France including 975 cases and 1317 controls, we found that the odds ratios for ER+, PR+ or HER2+ breast cancers subtypes were significantly elevated, while no association with night shift work was observed for ER, PR or HER2-negative tumors. After stratification by menopausal status, the associations of night work with receptor-positive breast tumor subtypes were clearly seen in premenopausal women (odds ratios 2.04, 1.98 and 2.80, respectively) but did not appear in postmenopausal women. This study provides evidence that working at night may increase risk of ER, PR and HER2-positive subtypes of breast cancer particularly among premenopausal women.
