Characteristics of breast cancer cases and controls in the BWHS
| Characteristic | Cases (n = 1199) | Controls (n = 1948) |
|---|---|---|
| Mean age, y | 47 | 47 |
| Region of residence, % | ||
| Northeast | 27 | 25 |
| South | 31 | 31 |
| Midwest | 25 | 25 |
| West | 17 | 18 |
| US born, % | 97.7 | 97.5 |
| First-degree family history of breast cancer, % | 13.4 | 8.2 |
| Global percent African ancestry, % | 80.6 | 80.5 |