Quintile of percent density | P* | Quintile of absolute density | P* | |||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

1 | 2 | 3 | 4 | 5 | 1 | 2 | 3 | 4 | 5 | |||||||||||

Percent dense volume (%) | Dense volume (cm^{3}) | |||||||||||||||||||

No. of cases | 44 | 45 | 56 | 59 | 67 | 45 | 49 | 46 | 65 | 66 | ||||||||||

No. of controls | 119 | 117 | 107 | 103 | 96 | 118 | 113 | 117 | 97 | 97 | ||||||||||

OR unadjusted (95% CI) | Reference | 1.04 (0.6, 1.7) | 1.42 (0.9, 2.3) | 1.55 (1.0, 2.5) | 1.89 (1.2, 3.0) | 0.002 | Reference | 1.14 (0.7, 1.8) | 1.03 (0.6, 1.7) | 1.76 (1.1, 2.8) | 1.78 (1.1, 2.8) | 0.002 | ||||||||

OR adjusted for risk factors^{†} (95% CI) | Reference | 1.06 (0.6, 1.7) | 1.48 (0.9, 2.4) | 1.72 (1.0, 2.8) | 2.21 (1.3, 3.7) | 0.001 | Reference | 1.15 (0.7, 1.9) | 1.04 (0.6, 1.7) | 1.82 (1.1, 2.9) | 1.86 (1.1, 3.0) | 0.003 | ||||||||

Percent dense area (%) | Dense area (cm^{2}) | |||||||||||||||||||

No. of cases | 41 | 45 | 68 | 56 | 61 | 40 | 46 | 55 | 67 | 63 | ||||||||||

No. of controls | 122 | 117 | 95 | 106 | 102 | 123 | 116 | 108 | 95 | 100 | ||||||||||

OR unadjusted (95% CI) | Reference | 1.14 (0.7, 1.9) | 2.13 (1.3, 3.4) | 1.57 (1.0, 2.5) | 1.78 (1.1, 2.9) | 0.01 | Reference | 1.22 (0.7, 2.0) | 1.57 (1.0, 2.5) | 2.17 (1.3, 3.5) | 1.94 (1.2, 3.1) | 0.0005 | ||||||||

OR adjusted for risk factors^{†} (95% CI) | Reference | 1.34 (0.8, 2.2) | 2.60 (1.6, 4.3) | 2.04 (1.2, 3.5) | 2.40 (1.3, 4.3) | 0.002 | Reference | 1.35 (0.8, 2.3) | 1.74 (1.0, 2.9) | 2.35 (1.4, 3.9) | 2.11 (1.3, 3.5) | 0.0005 |

NOTE: Shown are mean (SD) and percentage for, respectively, continuous and categorical variables.

↵* Unconditional logistic regression analysis.

*P*value is from a test of linear trend with quintiles as an ordinary variable in the model.↵† Age at mammogram (y), age at first birth (y), weight (kg), height (cm), menopausal status (premenopausal, postmenopausal), and parity (parous, nonparous).