Table 1.
Selected characteristics of study participants by case and control status in individual studies and the AMBER Consortium
| BWHS | WCHS | MEC | AMBER (total) | |||||
|---|---|---|---|---|---|---|---|---|
| Characteristic | Cases | Controls | Cases | Controls | Cases | Controls | Cases | Controls |
| Participants, n | 1984 | 7900 | 772 | 830 | 808 | 3113 | 3564 | 11843 |
| Age, years | 53.4 (10.7) | 52.5 (10.9) | 51.2 (10.3) | 49.8 (9.8) | 68.4 (9.4) | 67.8 (9.3) | 56.4 (12.2) | 56.3 (12.5) |
| Education | ||||||||
| 12 years | 43 (2.2) | 194 (2.5) | 109 (14.1) | 94 (11.3) | 91 (11.3) | 414 (13.3) | 243 (6.8) | 702 (5.9) |
| 12 years | 308 (15.5) | 1205 (15.3) | 233 (30.2) | 213 (25.7) | 200 (24.8) | 904 (29.0) | 741 (20.8) | 2322 (19.6) |
| Some college | 583 (29.4) | 2376 (30.1) | 206 (26.7) | 241 (29.0) | 302 (37.4) | 1149 (36.9) | 1091 (30.6) | 3766 (31.8) |
| College graduate | 449 (22.6) | 1814 (23.0) | 137 (17.7) | 174 (21.0) | 100 (12.4) | 338 (10.9) | 686 (19.2) | 2326 (19.6) |
| Any graduate or professions | 601 (30.3) | 2311 (29.3) | 87 (11.3) | 108 (13.0) | 115 (14.2) | 308 (9.9) | 803 (22.5) | 2727 (23.0) |
| BMI, kg/m2 | ||||||||
| 25.0 | 507 (25.6) | 1942 (24.6) | 152 (19.7) | 172 (20.7) | 191 (23.6) | 761 (24.4) | 850 (23.8) | 2875 (24.3) |
| 25.0–29.9 | 685 (34.5) | 2644 (33.5) | 235 (30.4) | 252 (30.4) | 277 (34.3) | 1173 (37.7) | 1197 (33.6) | 4069 (34.4) |
| ≥30.0 | 792 (39.9) | 3314 (41.9) | 385 (49.9) | 406 (48.9) | 340 (42.1) | 1179 (37.9) | 1517 (42.6) | 4899 (41.4) |
| First-degree family history of breast cancer | ||||||||
| No | 1671 (84.2) | 7157 (90.6) | 657 (85.1) | 731 (88.1) | 671 (83.0) | 2793 (89.7) | 2999 (84.1) | 10681 (90.2) |
| Yes | 313 (15.8) | 743 (9.4) | 115 (14.9) | 99 (11.9) | 137 (17.0) | 320 (10.3) | 565 (15.9) | 1162 (9.8) |
| Menopausal status | ||||||||
| Premenopausal | 788 (45.3) | 3263 (46.1) | 396 (54.4) | 429 (54.1) | 95 (12.2) | 298 (10.0) | 1279 (39.4) | 3990 (36.7) |
| Postmenopausal | 951 (54.7) | 3821 (53.9) | 332 (45.6) | 364 (45.9) | 683 (87.8) | 2695 (90.0) | 1966 (60.6) | 6880 (63.3) |
| Alcohol use | ||||||||
| Ever | 1176 (59.3) | 4835 (61.2) | 254 (32.9) | 289 (34.8) | 319 (39.5) | 1204 (38.7) | 1749 (49.1) | 6328 (53.4) |
| Never | 808 (40.7) | 3065 (38.8) | 518 (67.1) | 541 (65.2) | 489 (60.5) | 1909 (61.3) | 1815 (50.9) | 5515 (46.6) |
| Cigarette use | ||||||||
| Current smoker | 354 (17.8) | 1426 (18.1) | 111 (14.4) | 165 (19.9) | 165 (20.4) | 621 (19.9) | 630 (17.7) | 2212 (18.7) |
| Past smoker | 460 (23.2) | 1897 (24.0) | 177 (22.9) | 179 (21.6) | 290 (35.9) | 1075 (34.5) | 927 (26.0) | 3151 (26.6) |
| Never smoked | 1170 (59.0) | 4577 (57.9) | 484 (62.7) | 486 (58.6) | 353 (43.7) | 1417 (45.5) | 2007 (56.3) | 6480 (54.7) |
| Multivitamin use | ||||||||
| Current use | 977 (57.0) | 4270 (60.7) | — | — | 350 (84.5) | 1328 (82.2) | 1327 (62.4) | 5598 (64.7) |
| Past | 190 (11.1) | 925 (13.2) | — | — | 54 (13.0) | 248 (15.3) | 244 (11.5) | 1173 (13.6) |
| Never | 546 (31.9) | 1833 (26.1) | — | — | 10 (2.5) | 40 (2.5) | 556 (26.1) | 1873 (21.7) |
| Duration of multivitamin use, years | ||||||||
| 2 | 104 (6.6) | 400 (6.3) | — | — | 82 (20.5) | 396 (26.3) | 186 (9.5) | 796 (10.1) |
| 2–4 | 548 (34.9) | 2149 (33.5) | — | — | 97 (24.3) | 372 (24.7) | 645 (32.7) | 2521 (31.8) |
| 5–9 | 493 (31.4) | 2202 (34.3) | — | — | 221 (55.2) | 738 (49.0) | 714 (36.2) | 2940 (37.1) |
| ≥10 | 426 (27.1) | 1662 (25.9) | — | — | 0 | 0 | 426 (21.6) | 1662 (21.0) |
| Tumor ER status | ||||||||
| ER+ | 807 (65.2) | — | 415 (68.9) | — | 479 (74.0) | — | 1701 (68.4) | — |
| ER− | 431 (34.8) | — | 187 (31.1) | — | 168 (26.0) | — | 786 (32.6) | — |
Numbers are n (column %) or means (SD). Abbreviations: AMBER, African American Breast Cancer Epidemiology and Risk; BWHS, Black Women's Health Study; ER−, estrogen receptor negative; ER+, estrogen receptor positive; MEC, Multiethnic Cohort Study; WCHS, Women's Circle of Health Study.