Table 2.
Association between mammographic breast density and change in breast density and breast cancer risk, Women At Risk registry, Columbia University Medical Center
| Model 1 | Model 2 | Model 3 | |||
|---|---|---|---|---|---|
| Variables | Cases (N = 85) | Controls (N = 85) | Age-Adjusted Model1 OR (95% CI) | Additionally Adjusted for Parity, Family History, Menopausal Status OR (95% CI) | Adjusted for Parity, Family History, Menopausal Status, and Baseline Density2OR (95% CI) |
| Percent density, Time 1 (categorical)3 | |||||
| Less than 16% | 25 | 31 | Reference | Reference | |
| ≥16%, less than 34% | 33 | 26 | 1.66 (0.71–3.87) | 1.59 (0.58–4.33) | |
| 34% or greater | 27 | 28 | 1.93 (0.79–4.70) | 2.57 (0.81–8.10) | |
| pTrend = 0.15 | pTrend = 0.11 | ||||
| Percent density, time 2 (categorical) | |||||
| Less than 16% | 28 | 26 | Reference | Reference | Reference |
| 16%, less than 34% | 24 | 23 | 1.41 (0.56–3.55) | 1.40 (0.47–4.19) | 1.36 (0.43–4.28) |
| 34% or greater | 15 | 18 | 2.34 (0.69–7.92) | 1.55 (0.38–6.55) | 1.43 (0.33–6.22) |
| pTrend = 0.17 | pTrend = 0.54 | pTrend = 0.63 | |||
| Change in percent density (categorical) | |||||
| Greater than 5% decrease | 28 | 32 | 0.96 (0.41–2.25) | 0.78 (0.26–2.36) | 0.56 (0.15–2.17) |
| −5% to 5% change | 22 | 25 | Reference | Reference | Reference |
| Greater than 5% increase | 17 | 10 | 1.89 (0.71–5.06) | 2.42 (0.62–9.42) | 2.55 (0.63–10.26) |
| pTrend = 0.19 | pTrend = 0.10 | pTrend = 0.07 | |||
1
All models estimated using conditional logistic regression models, adjusted for age at first mammogram
2
Baseline density measures include dense area in cm2 at time 1, and percent density time 1.
3
Percent density at time 1 and time 2 cut-points were defined by tertiles of percent density for controls at first mammogram, rounded to nearest whole %.