Table 1.
Relation of participant characteristics with ultrasound tomography-derived volume averaged sound speed (VASS) among controls (n = 165).
| Volume Averaged Sound Speed (VASS) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Quartile 1: <1440.63 | Quartile 2: 1440.63 to <1445.65 | Quartile 3: 1445.65 to <1452.81 | Quartile 4: ≥1452.81 | ||||||
| Participant Characteristics | N | % | N | % | N | % | N | % | p-Value * |
| Age: Median (range) | 54.2 | (32.7, 67) | 50.9 | (40.7, 67.7) | 49.6 | (35.4, 69.2) | 48.4 | (36.8, 64.8) | 0.03 ** |
| Race | |||||||||
| White | 12 | 30.0 | 11 | 25.6 | 12 | 29.3 | 16 | 39.0 | |
| Black | 27 | 67.5 | 30 | 69.8 | 28 | 68.3 | 24 | 58.5 | 0.91 † |
| Other | 1 | 2.5 | 2 | 4.7 | 1 | 2.4 | 1 | 2.4 | |
| BMI, kg/m2 | |||||||||
| <25 | 3 | 7.5 | 6 | 14.3 | 6 | 14.6 | 21 | 51.2 | <0.0001 |
| 25–30 | 10 | 25.0 | 12 | 28.6 | 12 | 29.3 | 12 | 29.3 | |
| 30+ | 27 | 67.5 | 24 | 57.1 | 23 | 56.1 | 8 | 19.5 | |
| Education | |||||||||
| At most, high school/GED | 14 | 35.0 | 14 | 32.6 | 7 | 17.1 | 11 | 26.8 | 0.54 |
| Some college/postsecondary courses | 11 | 27.5 | 16 | 37.2 | 18 | 43.9 | 14 | 34.2 | |
| College/graduate school | 15 | 37.5 | 13 | 30.2 | 16 | 39.0 | 16 | 39.0 | |
| Age at menarche | |||||||||
| ≤12 | 26 | 66.7 | 27 | 62.8 | 22 | 53.7 | 19 | 46.3 | 0.34 |
| 13 | 9 | 23.1 | 6 | 14.0 | 11 | 26.8 | 12 | 29.3 | |
| 14+ | 4 | 10.3 | 10 | 23.3 | 8 | 19.5 | 10 | 24.4 | |
| Age at first birth | |||||||||
| Nulliparous/≥30 | 13 | 32.5 | 14 | 32.6 | 12 | 29.3 | 15 | 36.5 | 0.92 |
| <30 | 27 | 67.5 | 29 | 67.4 | 29 | 70.7 | 26 | 63.4 | |
| Menopausal status | |||||||||
| Premenopausal | 14 | 35.0 | 22 | 51.2 | 26 | 63.4 | 31 | 75.6 | 0.0019 |
| Postmenopausal | 26 | 65.0 | 21 | 48.8 | 15 | 36.6 | 10 | 24.4 | |
| Any first degree relative with breast cancer | |||||||||
| No | 30 | 75.0 | 32 | 74.4 | 39 | 95.1 | 32 | 78.1 | 0.056 |
| Yes | 10 | 25.0 | 11 | 25.6 | 2 | 4.9 | 9 | 22.0 | |
| BI-RADS breast density | |||||||||
| a (entirely fat) | 20 | 50.0 | 14 | 32.6 | 6 | 14.6 | 1 | 2.4 | <0.0001 |
| b (scattered densities) | 19 | 47.5 | 27 | 62.8 | 26 | 63.4 | 7 | 17.1 | |
| c (heterogeneously dense) | 1 | 2.5 | 2 | 4.7 | 8 | 19.5 | 26 | 63.4 | |
| d (extremely dense) | 0 | 0.0 | 0 | 0.0 | 1 | 2.4 | 7 | 17.1 | |
| Mammographic percent density, quartiles | |||||||||
| <7.8% | 17 | 42.5 | 18 | 41.9 | 6 | 14.6 | 0 | 0.0 | <0.0001 |
| 7.8 to <16.9% | 16 | 40.0 | 12 | 27.9 | 13 | 31.7 | 1 | 2.4 | |
| 16.9 to <30.8% | 7 | 17.5 | 8 | 18.6 | 15 | 36.6 | 10 | 24.4 | |
| ≥30.8% | 0 | 0.0 | 5 | 11.6 | 7 | 17.1 | 30 | 73.2 | |
Quartiles based upon distribution among controls; * p-values from Chi-square test except where noted; ** Kruskal–Wallis test; † Fisher’s exact test. BI-RADS: Breast Imaging Reporting and Data System.