Table 1. Number of subjects and median age in each group based on age at first pregnancy and the occurrence of subsequent breast cancer.
| Groups | Number of patients | Age at first pregnancy (median) | Age at cancer diagnosis (median) |
|---|---|---|---|
| 1 (nulliparous, no subsequent cancer) |
25 | - | - |
| 2 (nulliparous, subsequent cancer) |
10 | - | 35-79 (51) |
| 3 (early pregnancy, subsequent cancer) |
16 | 18-29 (23) | 34-71 (52) |
| 4 (early pregnancy, no subsequent cancer) |
36 | 18-27 (21) | - |
| 5 (late pregnancy, subsequent cancer) |
16 | 33-38 (36) | 39-69 (56) |
| 6 (late pregnancy, no subsequent cancer) |
22 | 32-39 (37) | - |