BRCA2 and breast cancer: In our study, it indicated an overall 18.4% (17.6% before age 50 years) prevalence of deleterious BRCA1/BRCA2 mutations in high‐risk women diagnosed with DCIS, supporting the presence of an in situ phase of carcinogenesis in the development of at least some BRCA‐associated breast cancer (Arun et al., 2009).