BRCA1 and breast carcinoma: Overall, TN cancers account for about 15% of all breast cancers, but occur more frequently in younger women and are the predominant cancer subtype in individuals with a germline BRCA1 mutation (Bauer et al, 2007; Atchley et al, 2008; Blows et al, 2010; Foulkes et al, 2010).