Table 1. Characteristics of 403 268 Women by Family History of Breast Cancer in the Breast Cancer Surveillance Consortium.
| Characteristic | No. (%)a | ||||
|---|---|---|---|---|---|
| All Mammograms (N = 472 220) | First-Degree Family History | ||||
| None (n = 397 040) | Any (n = 75 180) | Relative’s Diagnosis Age <50 y (n = 15 388) | Relative’s Diagnosis Age ≥50 y (n = 31 208) | ||
| Age at study entry, y | |||||
| 65-74 | 294 735 (60) | 249 875 (61) | 44 860 (57) | 9128 (56) | 18 699 (56) |
| ≥75 | 177 485 (38) | 147 165 (37) | 30 320 (40) | 6260 (41) | 12 509 (40) |
| BI-RADS densityb | |||||
| a | 70 122 (15) | 59 466 (15) | 10 656 (14) | 2147 (14) | 4276 (14) |
| b | 252 267 (53) | 212 562 (54) | 39 705 (53) | 8068 (52) | 16 081 (52) |
| c or d | 149 831 (32) | 125 012 (31) | 24 819 (33) | 5173 (34) | 10 851 (35) |
| Race/ethnicity | |||||
| White, non-Hispanic | 335 734 (71) | 278 081 (70) | 57 653 (77) | 11 976 (78) | 25 062 (80) |
| Black, non-Hispanic | 26 267 (6) | 23 005 (6) | 3262 (4) | 621 (4) | 991 (3) |
| Asian/Pacific islander | 23 589 (5) | 21 329 (5) | 2260 (3) | 717 (5) | 1219 (4) |
| Hispanic | 29 300 (6) | 25 578 (6) | 3722 (5) | 1038 (7) | 1483 (5) |
| Other or mixed | 4272 (1) | 3589 (1) | 683 (1) | 223 (1) | 338 (1) |
| Unknown | 53 058 (11) | 45458 (11) | 7600 (10) | 813 (5) | 2115 (7) |
| Benign breast disease | |||||
| None (no prior biopsy) | 374 462 (79) | 318 710 (80) | 55 752 (74) | 11 176 (73) | 23 025 (74) |
| Prior biopsy, unknown diagnosis | 81 540 (17) | 65 305 (16) | 16 235 (22) | 3399 (22) | 6639 (21) |
| Nonproliferative | 10 329 (2) | 8382 (2) | 1947 (3) | 473 (3) | 956 (3) |
| Proliferative without atypia | 4598 (1) | 3644 (1) | 954 (1) | 260 (2) | 448 (1) |
| Proliferative with atypia | 1014 (0.2) | 798 (0.2) | 216 (0.3) | 58 (0.4) | 105 (0.3) |
| Lobular carcinoma in situ | 277 (0.1) | 201 (0.1) | 76 (0.1) | 22 (0.1) | 35 (0.1) |
| Postmenopausal hormone therapy use | |||||
| No | 311 956 (66) | 261 732 (66) | 50 224 (67) | 10 578 (69) | 21 430 (69) |
| Yes | 92 365 (20) | 78 187 (20) | 14 178 (19) | 2629 (17) | 5650 (18) |
| Unknown | 67 899 (14) | 57 121 (14) | 10 778 (14) | 2181 (14) | 4128 (13) |
| BMI | |||||
| <18.5 | 4738 (1) | 3965 (1) | 773 (1) | 164 (1) | 348 (1) |
| 18.5-24.9 | 92 171 (20) | 76 219 (19) | 15 952 (21) | 3714 (24) | 7633 (24) |
| 25.0-29.9 | 73 905 (16) | 61 039 (15) | 12 866 (17) | 3389 (22) | 6085 (19) |
| 30.0-34.9 | 34 016 (7) | 28 030 (7) | 5986 (8) | 1608 (10) | 2968 (10) |
| ≥35.0 | 16 884 (4) | 13 794 (3) | 3090 (4) | 882 (6) | 1606 (5) |
| Unknown | 250 506 (53) | 213 993 (54) | 36 513 (49) | 5631 (37) | 12 568 (40) |
Abbreviations: BI-RADS, Breast Imaging Reporting and Data System; BMI, body mass index, calculated as weight in kilograms divided by height in meters squared.
a
Some columns do not sum to 100% due to rounding.
b
a Indicates almost entirely fat; b, scattered fibroglandular; c, heterogeneously dense; d, extremely dense. We grouped c and d categories together because they are not prevalent in older women.