Table 1 Characteristics of 297 cases and 1149 controls
From: Case-control study of mammographic density and breast cancer risk using processed digital mammograms
Cases | Controls | |||
|---|---|---|---|---|
N = 297 | % | N = 1149 | % | |
Age at mammogram | ||||
Mean (SD) | 63.79 | 7.21 | 63.95 | 7.00 |
Categories: | ||||
40–49 years | 9 | 3.0 % | 33 | 2.9 % |
50–59 years | 67 | 22.6 % | 238 | 20.7 % |
60–69 years | 149 | 50.2 % | 600 | 52.2 % |
70+ years | 72 | 24.2 % | 278 | 24.2 % |
Body mass index (kg/m2) | ||||
Mean (SD) | 28.71 | 6.88 | 27.48 | 5.88 |
Categories: | ||||
24 or less | 97 | 32.7 % | 471 | 41.0 % |
25–29 | 99 | 33.3 % | 347 | 30.2 % |
30–34 | 53 | 17.8 % | 213 | 18.5 % |
35–39 | 22 | 7.4 % | 71 | 6.2 % |
40+ | 26 | 8.8 % | 47 | 4.1 % |
First-degree family history of breast cancer | ||||
No | 257 | 86.5 % | 1058 | 92.1 % |
Yes | 40 | 13.5 % | 91 | 7.9 % |
Use of postmenopausal hormonesa | ||||
None | 237 | 79.8 % | 939 | 81.7 % |
Estrogen alone | 28 | 9.4 % | 106 | 9.2 % |
Estrogen + progestin | 32 | 10.8 % | 104 | 9.1 % |
Parity | ||||
Nulliparous | 18 | 6.1 % | 65 | 5.7 % |
Parous | 229 | 77.1 % | 916 | 79.7 % |
Missing | 50 | 16.8 % | 168 | 14.6 % |
Percent densityb | ||||
Mean (SD) | 22.00 | 13.81 | 19.51 | 14.77 |
Quintiles: | ||||
Q1: 6.08 or less | 40 | 13.5 % | 229 | 19.9 % |
Q2: 6.09–11.94 | 49 | 16.5 % | 230 | 20.0 % |
Q3: 11.95–20.04 | 60 | 20.2 % | 230 | 20.0 % |
Q4: 20.05–31.56 | 69 | 23.2 % | 230 | 20.0 % |
Q5: 31.57+ | 79 | 26.6 % | 230 | 20.0 % |
Area of densityb | ||||
Mean (SD) | 32.66 | 20.13 | 26.33 | 17.47 |
Quintiles: | ||||
Q1: 11.95 or less | 30 | 10.1 % | 229 | 19.9 % |
Q2: 11.96–19.09 | 45 | 15.2 % | 230 | 20.0 % |
Q3: 19.10–26.96 | 66 | 22.2 % | 230 | 20.0 % |
Q4: 26.97–37.78 | 68 | 22.9 % | 230 | 20.0 % |
Q5: 37.79+ | 88 | 29.6 % | 230 | 20.0 % |
Total breast area | ||||
Mean (SD) | 175.92 | 81.23 | 167.67 | 74.01 |