Table 2.

Standardized cumulative incidence of invasive breast cancer (cases per thousand women at risk) in joint strata of BI-RADS breast density and simple or detailed family history among Breast Cancer Screening Consortium participants, 1996–2013

Family historyCasesAlmost entirely fat (n = 20,736)Scattered fibroglandular densities (n = 79,756)Heterogeneously dense (n = 94,171)Extremely dense (n = 27,356)
Simple
 No first-degree history1,7891.4 (1.4–1.5)3.4 (3.2–3.5)5.2 (5.0–5.5)5.8 (5.5–6.1)
 First-degree family history6672.1 (2.0–2.2)4.7 (4.5–4.9)7.8 (7.4–8.2)8.7 (8.1–9.3)
Detailed
 No family history1,3291.5 (1.5–1.6)3.3 (3.1–3.4)5.0 (4.8–5.2)5.8 (5.5–6.1)
 Second degree only4521.0 (0.9–1.0)3.6 (3.4–3.8)5.9 (5.6–6.2)5.8 (5.4–6.1)
 First degree only4241.8 (1.8–1.9)4.4 (4.2–4.6)8.0 (7.7–8.4)10.0 (9.3–10.8)
 First and second degree2322.6 (2.5–2.7)5.2 (4.9–5.4)7.3 (7.0–7.6)6.8 (6.3–7.2)
 Malea192.2 (2.1–2.3)5.4 (5.1–5.6)5.8 (5.6–6.1)10.9 (10.4–11.4)
  • NOTE: Standardized using predictive marginals based on breast density (categorical), family history (categorical), age (continuous), age⁁2 (continuous), BMI (continuous), and BMI⁁2 (continuous), with interactions between breast density and family history, age, age squared, BMI, and BMI squared, and with interactions between family history and age, age squared, BMI, and BMI squared. Confidence intervals estimated using the Delta method approximations of the SE.

  • aWomen with a male relative affected by breast cancer were placed in the male relative category regardless of breast cancer among female relatives.