Table 2.

BC analysis: summary of the estimated parameters

	Overall sample					Relatives ofBRCA1mutation carriers					Relatives ofBRCA2mutation carriers
	py	Incident invasive BCs	IR per 1,000 py (95 % CI)	SIR (95% CI)	Cumulative risk,% (95% CI)	py	Incident invasive BCs	IR per 1,000 py (95 % CI)	SIR (95% CI)	Cumulative risk,% (95% CI)	py	Incident invasive BCs	IR per 1,000 py (95% CI)	SIR (95% CI)	Cumulative risk,% (95% CI)
Overall	13,398.1	23	1.72 (1.16–2.66)	0.93 (0.62–1.40)	NA	7,738.7	12	1.55 (0.90–2.92)	0.85 (0.48–1.50)	NA	5,632.4	11	1.95 (1.11–3.79)	1.03 (0.57–1.87)	NA
Age group
≥18 to <25	187.5	0	0	0	0	116.1	0	0	0	0	68.8	0	0	0	0
≥25 to <35	1,556.4	0	0	0	0	904.8	0	0	0	0	646.1	0	0	0	0
≥35 to <45	3,426.1	1	0.29 (-)	0.35 (0.05–2.45)	0.3 (0–1.8)	2,114.1	0	0	0	0	1,312	1	0.76 (-)	0.90 (0.13–6.42)	0.7 (0.1–4.7)
≥45 to <55	3,908.9	11	2.81 (1.59–5.47)	1.30 (0.72–2.35)	3 (1.7–5.3)	2,157.6	4	1.85 (0.70–6.64)	0.86 (0.32–2.30)	1.8 (0.7–4.8)	1,751.2	7	4.00 (1.95–9.52)	1.85 (0.88–3.87)	4.5 (2.3–8.8)
≥55 to <65	2,574.4	6	2.33 (1.06–6.13)	0.84 (0.38–1.87)	5.5 (3.5–8.8)	1,437.3	3	2.09 (0.65–10.2)	0.75 (0.24–2.31)	3.9 (1.8–8.2)	1,137.1	3	2.64 (0.82–12.9)	0.96 (0.31–2.97)	7.7 (4.2–14)
≥65 to <75	1,316	4	3.04 (1.14–10.9)	0.89 (0.33–2.37)	8.1 (5.2–12)	754.7	4	5.3 (1.99–18.9)	1.56 (0.59–4.16)	8.4 (4.5–15)	555.1	0	0	0	7.7 (4.2–14)
≥75 to <85	428.8	1	2.33 (-)	0.65 (0.09–4.59)	9.4 (5.9–15)	253.9	1	3.94 (-)	1.09 (0.15–7.73)	11 (5.6–19)	162	0	0	0	7.7 (4.2–14)
European ancestry	13,184.4	23	1.74 (1.17–2.70)	0.94 (0.63–1.42)	NA	7,587.7	12	1.58 (0.91–2.98)	0.87 (0.49–1.53)	NA	5,569.6	11	1.97 (1.12–3.83)	1.04 (0.58–1.88)	NA

Incidence rates, SIRs, and cumulative risks are reported for the overall sample and by family mutation.

BC, breast cancer; CI, confidence interval; IR, incidence rate; NA, not applicable; py, person-years; SIR, standardized incidence ratio.