Table 2.
Associations between percent density and variation measures and the risk of breast cancer (with corresponding AUCs)*
| Variable | MMHS | MCBCS | MCMAM study | ||||||
|---|---|---|---|---|---|---|---|---|---|
| No. of case subjects | Age-adjusted HR (95% CI) | Full model† HR (95% CI) | No. of case subjects | Age-adjusted OR (95% CI) | Full model† OR (95% CI) | No. of case subjects | Age-adjusted OR (95% CI) | Full model† OR (95% CI) | |
| Percent density: | |||||||||
| Quartile 1 (0–8.3%) | 51 | 1.0 (referent) | 1.0 (referent) | 91 | 1.0 (referent) | 1.0 (referent) | 50 | 1.0 (referent) | 1.0 (referent) |
| Quartile 2 (8.4–17.6%) | 52 | 1.3 (0.9 to 1.9) | 1.5 (1.0 to 2.2) | 179 | 1.5 (1.1 to 2.0) | 1.6 (1.2 to 2.2) | 50 | 1.0 (0.6 to 1.6) | 1.2 (0.73 to 1.8) |
| Quartile 3 (17.7–28.3%) | 43 | 1.3 (0.9 to 2.0) | 1.6 (1.1 to 2.5) | 253 | 1.7 (1.2 to 2.3) | 2.1 (1.5 to 2.8) | 68 | 1.5 (1.0 to 2.3) | 1.8 (1.1 to 2.8) |
| Quartile 4 (28.4–79.4%) | 71 | 2.3 (1.6 to 3.3) | 3.1 (2.0 to 4.8) | 405 | 3.0 (2.2 to 4.1) | 4.4 (3.1 to 6.1) | 78 | 2.2 (1.4 to 3.6) | 3.1 (1.9 to 5.1) |
| AUC (95% CI) | 0.63 (0.60 to 0.67) | 0.65 (0.62 to 0.69) | 0.62 (0.59 to 0.64) | 0.64 (0.62 to 0.67) | 0.59 (0.55 to 0.63) | 0.61 (0.58 to 0.66) | |||
| Per 1 SD increase in percent density‡ | 217 | 1.4 (1.2 to 1.6) | 1.6 (1.3 to 1.8) | 928 | 1.5 (1.4 to 1.7) | 1.8 (1.6 to 2.0) | 246 | 1.4 (1.2 to 1.7) | 1.6 (1.3 to 2.0) |
| AUC (95% CI) | 0.63 (0.59 to 0.66) | 0.65 (0.62 to 0.69) | 0.62 (0.60 to 0.65) | 0.65 (0.63 to 0.67) | 0.59 (0.55 to 0.64) | 0.61 (0.58 to 0.66) | |||
| Variation measure§ | |||||||||
| Quartile 1 (0–212) | 36 | 1.0 (referent) | 1.0 (referent) | 53 | 1.0 (referent) | 1.0 (referent) | 48 | 1.0 (referent) | 1.0 (referent) |
| Quartile 2 (213–280) | 22 | 0.9 (0.5 to 1.5) | 0.92 (0.5 to 1.6) | 109 | 1.3 (0.9 to 1.8) | 1.3 (0.9 to 1.9) | 65 | 1.6 (1.0 to 2.5) | 1.7 (1.1 to 2.6) |
| Quartile 3 (281–380) | 44 | 1.8 (1.2 to 2.8) | 2.1 (1.3 to 3.3) | 184 | 2.6 (1.8 to 3.6) | 3.0 (2.1 to 4.3) | 63 | 1.8 (1.2 to 2.9) | 1.9 (1.2 to 3.0) |
| Quartile 4 (381–809) | 115 | 5.8 (3.9 to 8.7)║ | 7.0 (4.6 to 10.4)║ | 582 | 8.2 (5.8 to 11.5)║ | 10.7 (7.5 to 15.3)║ | 70 | 2.4 (1.5 to 3.8) | 2.6 (1.6 to 4.2) |
| AUC (95% CI) | 0.70 (0.66 to 0.74)║ | 0.71 (0.68 to 0.75)║ | 0.72 (0.70 to 0.74)║ | 0.75 (0.73 to 0.77)║ | 0.58 (0.55 to 0.63) | 0.60 (0.57 to 0.65) | |||
| Per 1 SD increase in variation¶ | 217 | 2.3 (2.0 to 2.6)║ | 2.4 (2.1 to 2.7)║ | 928 | 2.8 (2.5 to 3.1)║ | 3.1 (2.8 to 3.5)║ | 246 | 1.4 (1.2 to 1.7) | 1.5 (1.2 to 1.8) |
| AUC (95% CI) | 0.70 (0.66 to 0.74)║ | 0.71 (0.68 to 0.75)║ | 0.75 (0.73 to 0.77)║ | 0.76 (0.74 to 0.79)║ | 0.58 (0.55 to 0.63) | 0.60 (0.58 to 0.66) | |||
* AUC = area under the receiver operating curve; MMHS = Mayo Mammography Health Study; MCBCS = Mayo Clinic Breast Cancer Study; MCMAM = Mayo Clinic Mammography; HR = hazard ratio; CI = confidence interval; OR = odds ratio; SD = standard deviation.
† Full model adjusted for age, body mass index, and menopausal status at mammogram.
‡ SD = 15.0.
§ In grayscale units.║ P < .001(two-sided) bootstrap-based comparison of variation estimates (either HR, OR, or AUC) to the corresponding percent density estimates.
¶ SD = 136.5.
** Variation measure in grayscale units.