Table 1.
Characteristics of women volunteers who donated normal breast tissue to the US-based Susan G. Komen Tissue Bank that were included in the current study (N = 4108)
| Characteristic | Overall, N (%) |
|---|---|
| Age, years | |
| < 30 | 819 (20.0) |
| 30–39 | 822 (20.0) |
| 40–49 | 909 (22.1) |
| 50–59 | 913 (22.2) |
| 60–75 | 645 (15.7) |
| Race/ethnicity | |
| Non-Hispanic White | 2953 (71.9) |
| Non-Hispanic Black/African American | 756 (18.4) |
| Asian/other | 381 (9.3) |
| Education | |
| High school/GED or less | 687 (16.7) |
| Vocation/tech school or associates degree | 694 (16.9) |
| College degree | 1331 (32.4) |
| Graduate/professional degree | 1037 (25.2) |
| Other | 338 (8.2) |
| Smoking | |
| Never | 2780 (67.7) |
| Former | 842 (20.5) |
| Current | 137 (3.3) |
| Currently drink alcohol | |
| No | 1372 (33.4) |
| Yes | 2699 (65.7) |
| Alcoholic drinks per week | |
| < 1 | 284 (6.9) |
| 1–6 | 1976 (48.1) |
| ≥ 7 | 252 (6.1) |
| Body mass index, kg/m2 | |
| < 25 | 1294 (31.5) |
| 25–29 | 1102 (26.8) |
| ≥ 30 | 1708 (41.6) |
| Age at menarche, years | |
| ≤ 12 | 2180 (53.1) |
| 13 | 1098 (26.7) |
| ≥ 14 | 826 (20.1) |
| Current hormonal birth control usea | |
| No | 2255 (83.6) |
| Yes | 441 (16.4) |
| Pregnancy | |
| Nulligravid | 1258 (30.6) |
| Gravid | 2849 (69.4) |
| Number of live births | |
| 0 | 197 (6.9) |
| 1 | 582 (20.4) |
| 2 | 1184 (41.6) |
| ≥ 3 | 719 (25.2) |
| Age at first full-term birth, years | |
| < 25 | 645 (22.6) |
| 25–29 | 428 (15.0) |
| ≥ 30 | 356 (12.5) |
| Breastfeeding | |
| Never | 810 (28.4) |
| Ever | 1818 (63.8) |
| Duration of breastfeeding, months | |
| Never | 810 (28.4) |
| < 12 | 971 (34.1) |
| ≥ 12– < 24 | 484 (17.0) |
| ≥ 24 | 359 (12.6) |
| Bilateral oophorectomyb | |
| No | 752 (53.2) |
| Yes | 295 (20.9) |
| Menopausal status | |
| Premenopausal | 2696 (65.6) |
| Postmenopausal | 1412 (34.4) |
| Menopausal hormone therapy usec | |
| Nonuser | 779 (55.2) |
| Current user | 217 (15.4) |
| Former user | 115 (8.1) |
| Type of current menopausal hormone therapy | |
| Estrogen only | 79 (36.4) |
| Progesterone only | 0 (0.0) |
| Combined estrogen and progesterone | 87 (40.1) |
| Type of former menopausal hormone therapy | |
| Estrogen only | 54 (46.9) |
| Progesterone only | 0 (0.0) |
| Combined estrogen and progesterone | 38 (33.0) |
| Family history of breast cancer | |
| Negative | 3006 (73.2) |
| Positive | 8.7 (20.4) |
Asian/Other category comprised women who self-identified as Asian, Chinese, Filipino, Japanese, “Other” Asian, Asian/Native Hawaiian or Pacific Islander, etc. Pregnant: Gravid = women who had previously been pregnant, irrespective of the outcome; nulligravid = women who had never been pregnant. Number of Live Births (0 = previous pregnancies did not result in a live birth). Percentages shown might not total to 100 due to missingness
aCurrent hormonal birth control use among pre-menopausal women. bFrequency of bilateral oophorectomy among postmenopausal women. cFrequency of menopausal hormone therapy use among postmenopausal women