BRCA2 and breast cancer: Screenings for BRCA1/2 mutations were the first genetic tests to assess a cancer risk.11 In 2003, King et al12 discovered that women who had a germline BRCA mutation had a 50%-80% increased risk of developing breast cancer and, depending on whether they had a BRCA1 or BRCA2 mutation, a 10%-40% increased risk of ovarian cancer development.