Table 2. Effect of percent density as measured by the Cumulus interactive threshold method on breast cancer risk, unadjusted, adjusted for BMI and adjusted for other significant risk factors.

	OR (95% CI)
Density	Unadjusted	Adjusted for BMI	Multivariate adjusteda
0–10	1.00 (−)	1.00 (−)	1.00 (−)
11–25	1.04 (0.65–1.68)	1.14 (0.70–1.85)	1.12 (0.68–1.84)
26–50	2.16 (1.39–3.35)	2.66 (1.69–4.20)	2.58 (1.62–4.12)
51–75	3.59 (2.23–5.78)	4.65 (2.83–7.64)	3.94 (2.36–6.57)
76–100	3.34 (1.55–7.20)	5.74 (2.54–12.95)	5.54 (2.38–12.90)

Abbreviations: BMI=body mass index; CI=confidence intervals; OR=odds ratio.

^aAdjusted for BMI, age at menarche, no. of deliveries, age at first birth, OC use, HRT use and menopausal status.