Table 3.

Cumulative 5-, 10-, and 15-year risks of contralateral breast cancer

Years after diagnosis	Overall % (n at risk)	BRCA1 mutation % (n at risk)	BRCA2 mutation % (n at risk)	Age < 40 % (n at risk)	Age ≥ 40 % (n at risk)
5	8 (198)	9 (140)	5 (58)	11 (86)	6 (112)
10	19 (98)	21 (75)	15 (23)	32 (39)	10 (59)
15	32 (47)	35 (37)	15 (10)	40 (17)	23 (30)

Cumulative 5-, 10-, and 15-year risks of contralateral breast cancer in different subgroups of breast cancer patients (BRCA1 mutation carriers vs. BRCA2 mutation carriers and age at primary breast cancer <40 vs. ≥40 years). Only those patients who underwent DNA testing for BRCA1/2 mutation before the diagnosis of contralateral breast cancer were included