Characteristics | Whole cohort | One woman per family sample cohort | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 |  | All women (N = 1337) | With BC (N = 499) | Without BC (N = 838) | All women (N = 990) | With BC (N = 379) | Without BC (N = 611) | ||||||
 |  | No | % | No | % | No | % | No | % | No | % | No | % |
Mutation | |||||||||||||
 | BRCA1 | 863 | 64.5 | 332 | 66.5 | 531 | 63.4 | 635 | 64.1 | 240 | 63.3 | 395 | 64.6 |
 | BRCA2 | 474 | 35.5 | 167 | 33.5 | 307 | 36.6 | 355 | 35.9 | 139 | 36.7 | 216 | 35.4 |
Age at interview, years | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | Â | |
 | Mean | 44.1 |  | 49.4 |  | 41.0 |  | 43.7 |  | 48.6 |  | 40.7 |  |
 | SD | 0.3 |  | 0.5 |  | 0.4 |  | 0.4 |  | 0.5 |  | 0.5 |  |
Age at diagnosis/censoring, years | |||||||||||||
 | Mean | 40.4 |  | 41.0 |  | 40.0 |  | 40.1 |  | 40.4 |  | 39.8 |  |
 | SD | 0.3 |  | 0.4 |  | 0.4 |  | 0.3 |  | 0.5 |  | 0.5 |  |
 | <30 | 196 | 14.7 | 34 | 6.8 | 162 | 19.3 | 142 | 14.3 | 29 | 7.7 | 113 | 18.5 |
 | 30 to 39 | 487 | 36.4 | 205 | 41.1 | 282 | 33.7 | 371 | 37.5 | 159 | 42.0 | 212 | 34.7 |
 | 40 to 49 | 403 | 30.1 | 176 | 35.3 | 227 | 27.1 | 306 | 30.9 | 133 | 35.1 | 173 | 28.3 |
 | 50 to 59 | 180 | 13.5 | 67 | 13.4 | 113 | 13.5 | 126 | 12.7 | 47 | 12.4 | 79 | 12.9 |
 | ≥60 | 71 | 5.3 | 17 | 3.4 | 54 | 6.4 | 45 | 4.5 | 11 | 2.9 | 34 | 5.6 |
Year of birth | |||||||||||||
 | <1950 | 354 | 26.5 | 201 | 40.3 | 153 | 18.3 | 237 | 23.9 | 139 | 36.7 | 98 | 16.0 |
 | 1950 to 1959 | 324 | 24.2 | 165 | 33.1 | 159 | 19.0 | 248 | 25.1 | 128 | 33.8 | 120 | 19.6 |
 | 1960 to1969 | 351 | 26.3 | 119 | 23.8 | 232 | 27.7 | 282 | 28.5 | 99 | 26.1 | 183 | 30.0 |
 | ≥1970 | 308 | 23.0 | 14 | 2.8 | 294 | 35.1 | 223 | 22.5 | 13 | 3.4 | 210 | 34.4 |
Oral contraceptive use | |||||||||||||
 | Never | 261 | 19.5 | 122 | 24.4 | 139 | 16.6 | 180 | 18.2 | 86 | 22.7 | 94 | 15.4 |
 | Ever | 1,058 | 79.1 | 373 | 74.7 | 685 | 81.7 | 798 | 80.6 | 290 | 76.5 | 508 | 83.1 |
 | Missing | 18 | 1.3 | 4 | 0.8 | 14 | 1.7 | 12 | 1.2 | 3 | 0.8 | 9 | 1.5 |
Number of full-term pregnancies | |||||||||||||
 | 0 | 293 | 21.9 | 68 | 13.6 | 225 | 26.8 | 217 | 21.9 | 58 | 15.3 | 159 | 26.0 |
 | 1 | 250 | 18.7 | 108 | 21.6 | 142 | 16.9 | 196 | 19.8 | 90 | 23.7 | 106 | 17.3 |
 | 2 | 452 | 33.8 | 182 | 36.5 | 270 | 32.2 | 346 | 34.9 | 139 | 36.7 | 207 | 33.9 |
 | ≥3 | 342 | 25.6 | 141 | 28.3 | 201 | 24.0 | 231 | 23.3 | 92 | 24.3 | 139 | 22.7 |
 | Missing | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 | 0 | 0.0 |
Induced abortion | |||||||||||||
 | 0 | 1,060 | 79.3 | 383 | 76.8 | 677 | 80.8 | 776 | 78.4 | 286 | 75.5 | 490 | 80.2 |
 | 1 | 213 | 15.9 | 81 | 16.2 | 132 | 15.8 | 168 | 17.0 | 67 | 17.7 | 101 | 16.5 |
 | 2 | 44 | 3.3 | 22 | 4.4 | 22 | 2.6 | 31 | 3.1 | 15 | 4.0 | 16 | 2.6 |
 | ≥3 | 12 | 0.9 | 8 | 1.6 | 4 | 0.5 | 9 | 0.9 | 7 | 1.8 | 2 | 0.3 |
 | Missing | 8 | 0.6 | 5 | 1.0 | 3 | 0.4 | 6 | 0.6 | 4 | 1.1 | 2 | 0.3 |
Spontaneous abortion | |||||||||||||
 | 0 | 1,085 | 81.2 | 387 | 77.6 | 698 | 83.3 | 791 | 79.9 | 293 | 77.3 | 498 | 81.5 |
 | 1 | 173 | 12.9 | 78 | 15.6 | 95 | 11.3 | 144 | 14.5 | 64 | 16.9 | 80 | 13.1 |
 | 2 | 50 | 3.7 | 22 | 4.4 | 28 | 3.3 | 34 | 3.4 | 12 | 3.2 | 22 | 3.6 |
 | ≥3 | 21 | 1.6 | 8 | 1.6 | 13 | 1.6 | 16 | 1.6 | 7 | 1.8 | 9 | 1.5 |
 | Missing | 8 | 0.6 | 4 | 0.8 | 4 | 0.5 | 5 | 0.5 | 3 | 0.8 | 2 | 0.3 |
Breast-feeding | |||||||||||||
 | Never | 439 | 32.8 | 187 | 37.5 | 252 | 30.1 | 308 | 31.1 | 130 | 34.3 | 178 | 29.1 |
 | Ever | 568 | 42.5 | 230 | 46.1 | 338 | 40.3 | 442 | 44.6 | 182 | 48.0 | 260 | 42.6 |
 | Missing | 37 | 2.8 | 14 | 2.8 | 23 | 2.7 | 23 | 2.3 | 9 | 2.4 | 14 | 2.3 |
 | Nulliparous | 293 | 21.9 | 68 | 13.6 | 225 | 26.8 | 217 | 21.9 | 58 | 15.3 | 159 | 26.0 |
Menopausal status | |||||||||||||
 | Premenopausal | 1,068 | 79.9 | 404 | 81.0 | 664 | 79.2 | 795 | 80.3 | 312 | 82.3 | 483 | 79.1 |
 | Postmenopausal | 240 | 18.0 | 86 | 17.2 | 154 | 18.4 | 171 | 17.3 | 60 | 15.8 | 111 | 18.2 |
 | Unknown | 29 | 2.2 | 9 | 1.8 | 20 | 2.4 | 24 | 2.4 | 7 | 1.8 | 17 | 2.8 |