Multiple large epidemiologic studies have shown that a relationship exists between self-reported alcohol drinking and breast cancer in women (Allen et al., 2009; Chen et al., 2011; Hamajima et al., 2002; IARC, 2010; Li et al., 2010). Therefore, additional epidemiologic studies further documenting this relationship are unlikely to increase our understanding. To assess mechanisms, and therefore develop mechanism based interventions, more information about drinking patterns over the lifetime in relation to breast cancer risk is needed. The study of Chen et al. (2011) represents an important first step in this direction, but more data are needed. Application of the lifetime exposure classification metrics which capture binge-type drinking at different age periods (e.g. Kerr and Ye, 2010) could be useful.
