Table 2.

Cumulative incidence of breast cancer in BRCA1/2 carriers, excluding index cases, in the study population (Northern Netherlands) and reference population (rest of the Netherlands)

BRCA1 carriersBRCA2 carriers
Age, yNorthern NetherlandsRest of the NetherlandsNorthern NetherlandsRest of the Netherlands
Crude risksN = 467N = 1,091N = 269N = 305
≤302.8 (1.5–4.7)3.7 (2.6–5.0)0.4 (0.0–2.2)0.7 (0.1–2.3)
≤4016.0 (12.4–20.0)23.1 (20.2–26.1)7.3 (4.3–11.4)13.3 (9.3–17.9)
≤5037.8 (31.9–43.6)46.6 (42.5–50.6)28.2 (21.3–35.6)37.6 (30.4–44.7)
≤6050.1 (43.2–56.7)61.1 (56.0–65.7)46.3 (36.5–55.6)54.8 (45.9–62.9)
≤7058.4 (50.2–65.7)67.9 (61.7–73.2)63.9 (50.3–74.7)60.6 (50.2–69.4)
≤7561.2 (51.5–69.4)71.0 (63.8–77.1)68.4 (52.7–79.8)
Weighted risksN = 467N = 913N = 269N = 229
≤301.9 (0.8–4.4)2.7 (1.4–5.4)0.3 (0.0–6.4)0.2(0.0–2.0)
≤4011.8 (8.4–16.4)17.0 (12.9–22.2)7.6 (4.1–13.8)9.5 (4.8–18.2)
≤5032.3 (26.4–39.0)36.0 (30.0–42.7)29.0 (21.3–38.6)29.9 (20.6–42.1)
≤6046.8 (39.8–54.4)49.9 (42.7–57.5)46.8 (36.8–58.1)49.1 (37.5–62.1)
≤7052.8 (45.1–61.0)54.6 (46.9–62.7)66.2 (54.2–77.7)63.7 (50.6–76.6)
≤7554.2 (46.2–62.7)58.6 (50.2–67.2)68.2 (55.8–80.0)

NOTE: Estimation of the crude risk and risk weighted to an equal contribution from the different birth cohorts and OCCR regions in each population (weighted risks).