Table 1. Characteristics of 1149 young women with unilateral and bilateral breast cancer included in this study.
| Characteristic | Bilateral (N=511) | Unilateral (N=638) | ||
|---|---|---|---|---|
| Age at diagnosis (mean and range) | ||||
| First primary | 46 | (25, 54) | 46 | (25, 54) |
| Second primary | 50 | (28, 68) | NA | NA |
| Follow-up (years) after diagnosisa(mean and range) | 10.8 | (2.4, 17.1) | 10.5 | (3.6, 16.9) |
| Race (N and %) | ||||
| White | 486 | 95.1% | 603 | 94.5% |
| Black | 10 | 2.0 | 13 | 2.0 |
| Asian or Pacific Islander | 2 | 0.4 | 8 | 1.3 |
| Native American, Aleut, or Eskimo | 3 | 0.6 | 3 | 0.5 |
| Other | 10 | 2.0 | 11 | 1.7 |
| Family history of breast cancer (N and %) | ||||
| Any first-degree relative | 161 | 31.5% | 128 | 20.1% |
| Mother | 108 | 21.1 | 86 | 13.5 |
| ⩾One sister | 76 | 14.9 | 53 | 8.3 |
| ⩾One daughter | 1 | 0.2 | 1 | 0.2 |
| Any second-degree relative | 148 | 29.0% | 149 | 23.4% |
| Maternal grandmother | 27 | 5.3 | 30 | 4.7 |
| Paternal grandmother | 25 | 4.9 | 21 | 3.3 |
| ⩾One maternal aunt | 63 | 12.3 | 70 | 11.0 |
| ⩾One paternal aunt | 54 | 10.6 | 56 | 8.8 |
a
Time between first primary diagnosis and interview date.