BRCA1 and ovarian cancer: Also, BRCA1/2 mutation carriers were more likely to have a family history of breast cancer and/or ovarian cancer (40.2% vs. 9.4%, P < 0.0001), personal history of ovarian cancer (9.0% vs. 0.5%, P < 0.0001), bilateral breast cancer (4.9% vs. 1.2%, P = 0.0105), and a higher nuclear grade (86.0% vs. 73.4%, P = 0.0140).