Tobacco Smoke and Breast Cancer

SSS senior research analyst Aimee D’Aloisio is among the authors of an article in Cancer Causes & Control that describes a prospective study to evaluate the association between tobacco smoke and breast cancer with a focus on the timing of exposure, especially during early life. All 50,884 Sister Study participants completed questionnaires on smoking and environmental tobacco smoke (ETS) exposure when they joined the study. During follow-up (mean = 6.4 years), 1,843 women were diagnosed with invasive breast cancer. Neither active smoking nor adult ETS was associated with breast cancer risk; however, among women who had never smoked, those with exposure to ETS during childhood and adolescence had a 17 percent higher risk of breast cancer relative to those with no exposure. In utero ETS exposure was also associated with breast cancer, with stronger associations among women born in earlier birth cohorts. The article was coauthored by researchers from the National Institute of Environmental Health Sciences, the University of North Carolina at Chapel Hill, and the University of Bergen.