In a retrospective study of 1042 BRCA1/2 carriers with breast cancer, Graeser demonstrated that the 25-year cumulative contralateral breast cancer risk for BRCA1 carriers with the first breast cancer diagnosis at age <40years, 40–50 years and >50 years, was 62.9% (95% CI 50.4–75.4), 43.7% (95% CI 24.9–62.5) and 19.6% (95% CI 5.3–33.9) respectively. This evidence concerns the gene BRCA1 and breast cancer.