Table 1.
Characteristics of Women With Breast Cancer and Controls Included in the Study Population, Breast Cancer Surveillance Consortium (1996–2015)
| Characteristic | Women, No. (%) | |||
|---|---|---|---|---|
| Premenopausal | Postmenopausal | |||
| Control (n = 52 860) |
Invasive and In Situ Cancer (n = 5286) |
Control (n = 131 449) |
Invasive and In Situ Cancer (n = 13 151) |
|
| Age, y | ||||
| 40–49 | 41 120 (77.8) | 4114 (77.8) | 4711 (3.6) | 471 (3.6) |
| 50–59 | 11 740 (22.2) | 1172 (22.2) | 48 868 (37.2) | 4882 (37.1) |
| 60–69 | NA | NA | 54 153 (41.2) | 5415 (41.2) |
| 70–74 | NA | NA | 23 717 (18.0) | 2383 (18.1) |
| Race/ethnicity | ||||
| White | 40 054 (75.8) | 4091 (77.4) | 104 157 (79.2) | 10 832 (82.4) |
| Black | 1295 (2.4) | 122 (2.3) | 3323 (2.5) | 279 (2.1) |
| Asian | 5670 (10.7) | 548 (10.4) | 11 177 (8.5) | 894 (6.8) |
| Hispanic | 2719 (5.1) | 208 (3.9) | 5105 (3.9) | 395 (3.0) |
| Other/mixed | 3122 (5.9) | 317 (6.0) | 7687 (5.8) | 751 (5.7) |
| Family history of breast cancer | ||||
| No | 46 020 (87.1) | 4181 (79.1) | 109 827 (83.6) | 10 035 (76.3) |
| Yes | 6840 (12.9) | 1105 (20.9) | 21 622 (16.4) | 3116 (23.7) |
| History of benign breast biopsy | ||||
| No | 45 658 (86.4) | 4193 (79.3) | 102 741 (78.2) | 9252 (70.4) |
| Yes | 7202 (13.6) | 1093 (20.7) | 28 708 (21.8) | 3899 (29.6) |
| Age at first live birth, y | ||||
| Nulliparous | 11 729 (22.2) | 1240 (23.5) | 20 236 (15.4) | 2350 (17.9) |
| Age <30 y | 29 060 (55.0) | 2615 (49.5) | 97 101 (73.9) | 9168 (69.7) |
| Age ≥30 y | 12 071 (22.8) | 1431 (27.1) | 14 112 (10.7) | 1633 (12.4) |
| BMI | ||||
| <18.5 | 924 (1.7) | 106 (2.0) | 2223 (1.7) | 173 (1.3) |
| 18.5–24.9 | 23 739 (44.9) | 2642 (50.0) | 45 341 (34.5) | 4194 (31.9) |
| 25.0–29.9 | 15 123 (28.6) | 1456 (27.5) | 43 937 (33.4) | 4476 (34.0) |
| 30.0–34.9 | 7192 (13.6) | 616 (11.7) | 23 321 (17.7) | 2493 (19.0) |
| ≥35.0 | 5882 (11.1) | 466 (8.8) | 16 627 (12.6) | 1815 (13.8) |
| BI-RADS breast density | ||||
| Almost entirely fat (a) | 2764 (5.2) | 95 (1.8) | 16 852 (12.8) | 1014 (7.7) |
| Scattered fibroglandular densities (b) | 17 256 (32.6) | 1248 (23.6) | 62 743 (47.7) | 5749 (43.7) |
| Heterogeneously dense (c) | 24 479 (46.3) | 2803 (53.0) | 44 686 (34.0) | 5448 (41.4) |
| Extremely dense (d) | 8361 (15.8) | 1140 (21.6) | 7168 (5.5) | 940 (7.1) |
| Type of cancer | ||||
| Invasive | NA | 3890 (73.6) | NA | 10 313 (78.4) |
| In situ | 1396 (26.4) | 2838 (21.6) | ||
| No. of risk factors | ||||
| None | 9749 (18.4) | 539 (10.2) | 11 222 (8.5) | 649 (4.9) |
| 1 | 20 793 (39.3) | 1759 (33.3) | 49 661 (37.8) | 3803 (28.9) |
| 2 | 17 509 (33.1) | 2039 (38.6) | 46 076 (35.1) | 4807 (36.6) |
| 3 | 4365 (8.3) | 821 (15.5) | 19 744 (15.0) | 2914 (22.2) |
| ≥4 | 444 (0.8) | 128 (2.4) | 4746 (3.6) | 978 (7.4) |
Abbreviations: BI-RADS, Breast Imaging Reporting and Data System; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); NA, not applicable.