Table 2. Age-specific penetrance of breast cancer (×100) by BRCA1 and BRCA2 mutation status, estimated using data from the first-degree relatives by the modified kin-cohort method.

	BRCA1 carrier	BRCA2 carrier	Non-carrier
Age Interval	Penetrance (95% CI)	Penetrance (%) (95% CI)	Penetrance (%) (95% CI)
20-40 years	10.0 (4.7-15.7)	6.7 (3.2-11.0)	1.1 (0.8-1.5)
20-50 years	16.3 (8.6-25.0)	21.1 (12.3-31.1)	6.3 (5.4-7.2)
20-60 years	30.5 (18.0-46.6)	31.4 (21.6-42.6)	11.8 (10.5-13.0)
20-70 years	53.7 (34.5-71.6)	48.3 (31.8-68.5)	16.1 (14.3-17.8)