Secondhand suspicions: Breast cancer and passive smoking

Abstract

The suspicion that exposure to secondhand smoke could cause breast cancer dates back more than two decades. This hypothesis continues to be controversial, however, with experts split over whether the data are sufficient to support such a link. In earlier studies, the factors of exposure assessment and age made it difficult to tease out the contribution of secondhand smoke to breast cancer risk. New research is under way to provide clearer information on these factors.