BRCA1 and ductal breast carcinoma in situ: They also found that the number of pure DCIS cases was similar in BRCA1 and BRCA2 mutations carriers (21% vs 23%), in contrast to Krammer et al. who reported that pure DCIS was more frequent in BRCA2 mutation carriers compared to BRCA1 carriers (5%, 36/246, versus 9%, 23/250, P = 0.0026) [24].