Table 1.
Characteristics of subjects by study and case–control status*
| Variable | MMHS | MCBCS | MCMAM study | |||
|---|---|---|---|---|---|---|
| Case subjects | Subcohort (Control subjects) | Case subjects | Control subjects | Case subjects | Control subjects | |
| Number of women | 217 | 2094 | 928 | 1039 | 246 | 515 |
| Mean age at mammogram, y (SD) | 55.3 (10.7) | 51.6 (11.0) | 59.3 (11.8) | 61.4 (11.0) | 64.9 (10.1) | 64.1 (10.2) |
| Mean BMI at mammogram, kg/m2 (SD) | 28.2 (5.7) | 27.7 (6.7) | 27.6 (5.6) | 27.0 (5.3) | 27.9 (5.0) | 27.5 (5.2) |
| Menopausal status at mammogram, No. (%) | ||||||
| Premenopausal | 93 (43) | 1121 (54) | 238 (25) | 201 (19) | 21 (8) | 40 (8) |
| Postmenopausal | 124 (57) | 973 (46) | 676 (73) | 831 (80) | 223 (91) | 471 (91) |
| Unknown | 0 (0) | 0 (0) | 14 (2) | 7 (1) | 2 (1) | 4 (1) |
| Invasive cancer, No. (%) | 155 (71) | – | 748 (81) | – | 193 (78) | – |
| Mean density, % (SD) | 21.6 (15.3) | 19.7 (15.1) | 27.4 (15.1) | 21.4 (14.0) | 22.5 (15.0) | 18.3 (13.6) |
| Mean variation† (SD) | 383.3 (145.1) | 305.33 (125.1) | 435.3 (146.5) | 311.5 (109.3) | 320.4 (126.3) | 285.0 (115.8) |
* MMHS = Mayo Mammography Health Study; MCBCS = Mayo Clinic Breast Cancer Study; MCMAM = Mayo Clinic Mammography; BMI = body mass index; – = not applicable.
† In grayscale units.