Cumulative incidence of breast cancers in BRCA1 mutations carriers by the age of 50 and 70 is ~50% and ~85%, respectively. Thus, many carriers will develop breast cancer after 50 years of age. The reason why the cohort studies limit recruitment to 50 years of patient's age in my view reflects the fact that breast cancer in older women is often different than in younger women  and the difference can also exist between older and younger BRCA1-associated breast cancers. It is known that while majority of BRCA1-associated breast cancers are triple-negative, some of them are ER-positive and the proportion of ER-positive BRCA1-associated breast cancers increases with the age at diagnosis. Consequently, limiting age of patients to

Eerola H, Heikkilä P, Tamminen A, Aittomäki K, Blomqvist C, Nevanlinna H. Relationship of patients’ age to histopathological features of breast tumours in BRCA1 and BRCA2 and mutation-negative breast cancer families. Breast Cancer Research. 2005;7(4):R465-R469. doi:10.1186/bcr1025