Table 3

RRs of breast cancer in relation to combinations of Wolfe class and percent density on prior screening mammograms

Wolfe class and percent densityCasesControlsRRa (95% CI)
P1
 ≤26.7%471021.0 (reference)
 26.8–50.1%15330.9 (0.4–1.8)
P2
 26.8–50.1%77841.9 (1.2–3.1)
 50.2–70.2%1711153.1 (2.0–4.8)
 >70.2%168983.4 (2.2–5.4)
DY
 >70.2%58205.8 (3.2–11)
  • a Adjusted for age, study, and mammographic calcifications.