Occupational exposure to ionizing radiation and risk of breast cancer in Western Australia

OBJECTIVE:: To evaluate current breast cancer risk due to occupational exposure to ionizing radiation. METHODS:: We analyzed data from the Western Australian population-based Breast Cancer Employment and Environment Study. The Breast Cancer Employment and Environment Study included 1205 cases with incident breast cancer during 2009-2011 and 1789 controls. Age-adjusted odds ratios (ORs) were estimated with logistic regression models. RESULTS:: There was a weak, not statistically significant association between breast cancer and occupational exposure to ionizing radiation (OR = 1.16; 95% confidence interval, 0.86 to 1.57). The risk of human epidermal growth factor receptor 2-positive breast cancer with occupational exposure to ionizing radiation in women who were premenopausal at the time of interview was higher (OR = 2.57; 95% confidence interval, 1.09 to 6.03). CONCLUSIONS:: This study suggests that the risk of breast cancer is low at current levels of occupational exposure to ionizing radiation, although the risk of human epidermal growth factor receptor 2-positive cancer may be a concern.