BRCA1 and breast cancer: Second primary breast cancers (2.12 v 1.42 events per 100 person-year) and nonbreast primary malignancies (0.70 v 0.45 events per 100 person-year) were more frequent among BRCA1 than BRCA2 carriers, whereas distant recurrences were less frequent (1.51 v 2.06 events per 100 person-year).