BRCA1 and breast cancer: Of 625 early onset patients, BRCA1 and BRCA2 mutations were detected in 35 (6.4%) of 550 patients without other risks, in 16 (30.2%) of 53 patients with bilateral breast cancer, in one (100%) patient who also had ovarian cancer, and in one (5.3%) of 19 patients with multiple organ cancers (Table 3).