A recently published study of Dutch patients (including 200 BRCA1 carriers, 71 BRCA2 carriers, and 6023 non-carriers) showed that the contralateral breast cancer (breast cancer in the opposite breast) risks at 10 years was 21.1% for BRCA1, 10.8% for BRCA2, and 5.1% for non-carriers. Among BRCA mutation carriers, it was important to take age at diagnosis of the first breast cancer into account to refine the 10-year risk of a second breast cancer diagnosis as follows: for those diagnosed at age 40 or younger, risks were 25.5% for BRCA1 and 17.2% for BRCA2; for those diagnosed between 41-49 years, risks were 15.6% for BRCA1 and 7.2% for BRCA2. These findings show that it is important to provide age-specific risk estimates to BRCA mutation carriers as part of the counseling process in order for patients to make informed decisions about their cancer risk management.
van den Broek AJ, et al. J Clin Oncol. 2015 Dec 23.PMID: 26700119.