Table 2.
Distributions of quantitative tissue composition metrics according to 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 | Epithelium (%) | Stroma (%) | Adipose tissue (%) | Fibroglandular tissue (%) | Epithelium-to-stroma proportion (%) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | Median (range) | Mean | Median (range) | Mean | Median (range) | Mean | Median (range) | Mean | Median (range) | |
| Overall | 2.1 | 0.89 (0.0–70.4) | 24.6 | 17.2 (0.0–95.7) | 73.3 | 81.0 (0.0–100.0) | 26.7 | 18.9 (0.0–97.2) | 9.2 | 5.9 (0.0–100.0) |
| Age, years | ||||||||||
| < 30 | 3.0 | 1.46 (0.0–25.1) | 35.3 | 29.0 (0.0–93.5) | 61.8 | 68.0 (5.1–100.0) | 38.3 | 32.0 (0.0–94.9) | 9.0 | 5.6 (0.0–85.2) |
| 30–39 | 2.8 | 1.31 (0.0–53.4) | 25.9 | 18.7 (0.0–92.2) | 71.3 | 79.1 (6.1–100.0) | 28.7 | 20.9 (0.0–93.9) | 10.1 | 7.7 (0.0–98.7) |
| 40–49 | 2.2 | 1.02 (0.0–70.4) | 22.4 | 16.3 (0.0–91.8) | 75.4 | 82.3 (7.3–100.0) | 24.6 | 17.7 (0.0–92.7) | 9.8 | 6.6 (0.0–100.0) |
| 50–59 | 1.3 | 0.65 (0.0–18.4) | 21.0 | 14.7 (0.0–91.3) | 77.7 | 84.2 (6.4–100.0) | 22.3 | 15.8 (0.0–93.6) | 8.3 | 5.2 (0.0–100.0) |
| 60–75 | 1.0 | 0.49 (0.0–13.0) | 17.9 | 11.0 (0.0–95.8) | 81.1 | 88.4 (2.8–100.0) | 18.9 | 11.6 (0.0–97.2) | 9.0 | 4.7 (0.0–93.8) |
| P value | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | |||||
| Race/ethnicity | ||||||||||
| Non-Hispanic Caucasian | 2.0 | 0.90 (0.0–53.4) | 25.3 | 18.0 (0.0–95.8) | 72.7 | 80.5 (2.8–100.0) | 27.3 | 19.5 (0.0–97.2) | 8.9 | 5.7 (0.0–100.0) |
| Black/African American | 2.2 | 0.89 (0.0–70.4) | 21.5 | 15.1 (0.0–88.9) | 76.3 | 83.3 (6.1–100.0) | 23.7 | 16.7 (0.0–93.9) | 9.9 | 6.7 (0.0–92.2) |
| Asian/other | 2.2 | 0.89 (0.0–25.1) | 25.8 | 17.6 (0.0–91.8) | 72.0 | 81.3 (6.1–100.0) | 28.0 | 18.7 (0.0–93.9) | 10.4 | 6.5 (0.0–92.9) |
| P value | 0.98 | 0.02 | 0.08 | 0.08 | 0.01 | |||||
| Education | ||||||||||
| High school/GED or less | 2.4 | 0.96 (0.0–70.4) | 29.0 | 20.5 (0.0–93.3) | 68.6 | 77.5 (5.1–100.0) | 31.4 | 22.5 (0.0–94.9) | 9.6 | 5.7 (0.0–100.0) |
| Vocation/tech school or associates degree | 1.9 | 0.84 (0.0–21.3) | 21.2 | 14.9 (0.0–95.8) | 76.9 | 83.7 (2.8–100.0) | 23.1 | 16.3 (0.0–97.2) | 9.2 | 6.6 (0.0–100.0) |
| College degree | 2.1 | 0.94 (0.0–26.6) | 35.6 | 18.6 (0.0–92.7) | 72.3 | 79.9 (5.7–100.0) | 27.7 | 20.1 (0.0–94.3) | 9.0 | 5.8 (0.0–93.7) |
| Graduate/professional degree | 2.1 | 0.87 (0.0–53.4) | 23.2 | 16.1 (0.0–93.1) | 74.7 | 82.8 (6.4–100.0) | 25.3 | 17.2 (0.0–93.6) | 9.6 | 6.0 (0.0–98.7) |
| Other | 1.9 | 0.85 (0.0–17.6) | 24.0 | 17.3 (0.0–93.5) | 74.1 | 80.8 (5.6–100.0) | 25.9 | 19.2 (0.0–94.4) | 8.5 | 5.7 (0.0–87.1) |
| P value | 0.58 | < 0.0001 | < 0.0001 | < 0.0001 | 0.34 | |||||
| Smoking | ||||||||||
| Never | 2.2 | 0.95 (0.0–53.4) | 25.1 | 18.1 (0.0–95.8) | 72.7 | 80.4 (2.8–100.0) | 27.3 | 19.6 (0.0–97.2) | 9.1 | 6.0 (0.0–100.0) |
| Former | 1.6 | 0.72 (0.0–70.4) | 22.9 | 15.7 (0.0–92.1) | 75.5 | 83.3 (6.3–100.0) | 24.5 | 16.7 (0.0–93.7) | 9.0 | 5.3 (0.0–100.0) |
| Current | 1.9 | 0.96 (0.0–9.76) | 27.7 | 22.1 (0.0–92.5) | 70.4 | 77.0 (5.7–100.0) | 29.6 | 23.0 (0.0–94.8) | 10.0 | 6.1 (0.0–93.7) |
| P value | 0.008 | 0.13 | 0.02 | 0.02 | 0.03 | |||||
| Currently drink alcohol | ||||||||||
| No | 2.0 | 0.86 (0.0–70.4) | 23.1 | 15.3 (0.0–95.8) | 74.8 | 83.2 (2.8–100.0) | 25.2 | 16.8 (0.0–97.2) | 9.6 | 6.3 (0.0–100.0) |
| Yes | 2.1 | 0.92 (0.0–53.4) | 25.4 | 18.4 (0.0–93.1) | 72.5 | 80.2 (5.1–100.0) | 27.5 | 19.8 (0.0–94.9) | 9.0 | 5.8 (0.0–100.0) |
| P value | 0.73 | 0.02 | 0.69 | 0.03 | 0.06 | |||||
| Average number of alcoholic drinks per week | ||||||||||
| < 1 | 2.0 | 0.84 (0.0–23.3) | 22.9 | 13.8 (0.0–84.6) | 75.1 | 84.1 (10.5–100.0) | 24.9 | 15.9 (0.0–89.5) | 10.9 | 7.0 (0.2–93.7) |
| 1–6 | 2.2 | 0.91 (0.0–53.4) | 25.6 | 18.8 (0.0–93.1) | 72.2 | 79.1 (5.1–100.0) | 27.8 | 20.3 (0.0–95.9) | 8.8 | 5.6 (0.0–100.0) |
| ≥ 7 | 1.7 | 0.92 (0.0–15.4) | 26.8 | 18.7 (0.0–91.9) | 71.5 | 69.9 (6.9–100.0) | 28.5 | 20.1 (0.0–93.0) | 7.2 | 4.7 (0.0–62.4) |
| P value | 0.69 | 0.003 | 0.006 | 0.006 | < 0.0001 | |||||
| Body mass index | ||||||||||
| < 25 | 2.6 | 1.25 (0.0–53.4) | 32.4 | 26.1 (0.0–95.8) | 65.0 | 71.9 (2.8–100.0) | 35.0 | 28.1 (0.0–97.2) | 8.0 | 5.1 (0.0–98.7) |
| 25–29 | 1.9 | 0.79 (0.0–36.2) | 23.6 | 15.8 (0.0–93.5) | 74.5 | 82.4 (5.6–100.0) | 25.5 | 17.6 (0.0–94.4) | 9.2 | 5.9 (0.0–100.0) |
| ≥ 30 | 1.8 | 0.74 (0.0–70.4) | 19.5 | 12.9 (0.0–92.4) | 78.7 | 85.6 (6.1–100.0) | 21.3 | 14.4 (0.0–93.9) | 1.0 | 6.9 (0.0–97.5) |
| P value | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | |||||
| Age at menarche, years | ||||||||||
| ≤ 12 | 2.1 | 0.89 (0.0–70.4) | 23.5 | 16.1 (0.0–92.7) | 74.4 | 82.4 (5.1–100.0) | 25.6 | 17.6 (0.0–94.9) | 9.5 | 6.3 (0.0–100.0) |
| 13 | 2.1 | 0.95 (0.0–53.4) | 25.7 | 18.2 (0.0–95.8) | 72.1 | 80.3 (2.8–100.0) | 27.9 | 19.7 (0.0–97.2) | 8.9 | 5.4 (0.0–89.7) |
| ≥ 14 | 2.0 | 0.86 (0.0–24.9) | 26.2 | 19.2 (0.0–93.1) | 71.9 | 79.2 (5.2–100.0) | 28.1 | 20.8 (0.0–94.8) | 9.0 | 5.6 (0.0–100.0) |
| P value | 0.54 | 0.009 | 0.01 | 0.01 | 0.002 | |||||
| Current hormonal birth control use | ||||||||||
| No | 2.6 | 1.18 (0.0–70.4) | 27.3 | 19.9 (0.0–93.5) | 70.1 | 77.8 (5.1–100.0) | 29.9 | 22.2 (0.0–94.9) | 9.6 | 6.5 (0.0–100.0) |
| Yes | 2.7 | 1.48 (0.0–24.7) | 29.2 | 21.2 (0.0–92.7) | 68.2 | 76.4 (6.3–99.9) | 27.0 | 23.6 (0.0–93.7) | 9.7 | 6.8 (0.0–85.2) |
| P value | 0.10 | 0.29 | 0.28 | 0.28 | 0.29 | |||||
| Parity | ||||||||||
| Nulliparous | 2.2 | 0.88 (0.0–25.1) | 27.9 | 18.9 (0.0–93.5) | 70.0 | 79.4 (5.1–100.0) | 30.0 | 20.6 (0.0–94.9) | 8.9 | 5.3 (0.0–100.0) |
| Parous | 2.1 | 0.91 (0.0–70.4) | 23.2 | 16.6 (0.0–95.8) | 74.8 | 81.8 (2.8–100.0) | 25.2 | 18.2 (0.0–97.2) | 9.4 | 6.3 (0.0–100.0) |
| P value | 0.44 | 0.13 | 0.06 | 0.06 | < 0.0001 | |||||
| Number of live births | ||||||||||
| 0 | 1.9 | 0.74 (0.0–21.3) | 26.8 | 21.2 (0.02–87.5) | 71.3 | 76.7 (9.1–100.0) | 28.7 | 23.3 (0.0–90.9) | 7.6 | 5.3 (0.0–51.1) |
| 1 | 1.8 | 0.91 (0.0–26.6) | 23.4 | 16.8 (0.0–89.7) | 74.8 | 81.8 (6.1–100.0) | 25.2 | 18.2 (0.0–93.9) | 8.9 | 5.8 (0.0–97.5) |
| 2 | 2.1 | 0.98 (0.0–36.2) | 22.7 | 15.6 (0.0–91.3) | 75.2 | 82.5 (6.4–100.0) | 24.8 | 17.5 (0.0 93.6) | 9.8 | 6.7 (0.0–100.0) |
| ≥ 3 | 2.1 | 0.87 (0.0–70.4) | 21.1 | 15.0 (0.0–95.8) | 76.9 | 83.6 (2.8–100.0) | 23.1 | 16.4 (0.0–97.2) | 10.1 | 6.9 (0.0–82.5) |
| P value | 0.69 | < 0.0001 | 0.0003 | 0.0003 | < 0.0001 | |||||
| Age at first full-term birth, years | ||||||||||
| < 25 | 2.0 | 0.83 (0.0–26.6) | 21.6 | 15.0 (0.0–95.8) | 76.4 | 84.1 (2.8–100.0) | 23.6 | 15.9 (0.0–97.2) | 8.7 | 6.3 (0.0–88.0) |
| 25–29 | 2.1 | 1.06 (0.0–53.4) | 23.4 | 18.7 (0.0–85.9) | 74.4 | 79.9 (7.7–100.0) | 25.6 | 20.1 (0.0–92.2) | 8.9 | 5.9 (0.0–100.0) |
| ≥ 30 | 2.1 | 1.08 (0.0–36.2) | 23.4 | 17.2 (0.0–91.3) | 74.5 | 81.2 (6.4–100.0) | 25.5 | 18.8 (0.0–93.6) | 9.1 | 5.7 (0.0–68.6) |
| P value | 0.35 | 0.38 | 0.3612 | 0.36 | 0.0038 | |||||
| Breastfeeding | ||||||||||
| Never | 1.6 | 0.68 (0.0–70.4) | 20.2 | 13.5 (0.0–95.8) | 78.2 | 85.6 (2.8–100.0) | 21.8 | 14.4 (0.0–97.2) | 9.8 | 6.2 (0.0–97.5) |
| Ever | 2.2 | 1.05 (0.0–53.4) | 23.5 | 17.5 (0.0–91.3) | 74.3 | 80.9 (6.1–100.0) | 25.7 | 19.1 (0.0–93.9) | 9.5 | 6.6 (0.0–100.0) |
| P value | 0.0002 | < 0.0001 | < 0.0001 | < 0.0001 | 0.0002 | |||||
| Breastfeeding duration, months | ||||||||||
| Never | 1.6 | 0.7 (0.0–70.4) | 20.2 | 13.5 (0.0–95.8) | 78.2 | 85.6 (2.8–100.0) | 21.8 | 14.4 (0.0–97.2) | 9.8 | 6.2 (0.0–97.5) |
| < 12 | 2.1 | 1.04 (0.0–26.6) | 23.2 | 18.0 (0.0–91.3) | 74.7 | 80.5 (6.1–100.0) | 25.3 | 19.5 (0.0–93.9) | 9.4 | 6.5 (0.0–100.0) |
| ≥ 12– < 24 | 2.2 | 1.02 (0.0–36.2) | 23.9 | 16.2 (0.0–89.3) | 73.9 | 82.3 (8.6–100.0) | 26.1 | 17.7 (0.0–91.4) | 9.2 | 6.6 (0.0–65.9) |
| ≥ 24 | 2.5 | 1.15 (0.0–53.4) | 23.8 | 17.0 (0.0–90.5) | 73.7 | 81.0 (7.7–100.0) | 26.3 | 19.0 (0.0–92.2) | 10.1 | 7.0 (0.0–91.0) |
| P value | 0.0016 | < 0.0001 | < 0.0001 | < 0.0001 | 0.002 | |||||
| Bilateral oophorectomy | ||||||||||
| No | 1.2 | 0.60 (0.0–18.4) | 20.5 | 13.9 (0.0–90.6) | 78.3 | 85.2 (9.2–100.0) | 21.7 | 14.8 (0.0–90.8) | 8.5 | 5.2 (0.0–93.7) |
| Yes | 1.0 | 0.47 (0.0–12.0) | 17.5 | 11.6 (0.0–79.3) | 81.8 | 87.6 (20.4–100.0) | 18.2 | 12.4 (0.0–79.6) | 8.5 | 4.7 (0. 0–97.5) |
| P value | 0.01 | 0.02 | 0.02 | 0.02 | 0.12 | |||||
| Menopausal status | ||||||||||
| Premenopausal | 2.6 | 1.26 (0.0–70.4) | 28.1 | 20.6 (0.0–93.5) | 69.3 | 77.1 (5.1–100.0) | 30.7 | 22.9 (0.0–94.9) | 9.7 | 6.6 (0.0–100.0) |
| Postmenopausal | 1.2 | 0.56 (0.0–21.3) | 19.1 | 12.6 (0.0–95.8) | 79.7 | 86.2 (2.8–100.0) | 20.3 | 13.8 (0.0–97.2) | 8.4 | 5.0 (0.0–100.0) |
| Uterine Ablation | 2.3 | 1.07 (0.0–18.4) | 25.7 | 20.6 (0.0–89.9) | 72.0 | 77.5 (7.8–80.5) | 28.0 | 22.5 (0.0–92.1) | 10.2 | 7.6 (0.12–74.0) |
| P value | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | < 0.0001 | |||||
| Menopausal hormone therapy | ||||||||||
| Nonuser | 1.2 | 0.53 (0.0–18.4) | 18.6 | 12.7 (0.0–91.3) | 80.2 | 86.2 (6.4–100.0) | 19.8 | 13.8 (0.0–93.6) | 8.8 | 5.2 (0.0–100.0) |
| Current user | 0.8 | 0.45 (0.0 10.0) | 20.3 | 12.2 (0.0–95.8) | 78.9 | 87.2 (2.7–100.0) | 21.1 | 12.8 (0.0–97.2) | 6.2 | 3.1 (0.0–87.1) |
| Former user | 1.4 | 0.52 (0.0–13.0) | 19.9 | 15.3 (0.0–90.6) | 78.7 | 83.5 (9.3–100.0) | 21.3 | 16.5 (0.0–90.7) | 8.0 | 5.3 (0.0–55.9) |
| P value | 0.0006 | 0.63 | 0.67 | 0.67 | < 0.0001 | |||||
| Menopausal hormone therapy type-current user | ||||||||||
| Nonuser | 1.2 | 0.53 (0.0–18.4) | 18.6 | 12.6 (0.0–91.3) | 80.3 | 86.2 (6.4–100.0) | 19.7 | 13.8 (0.0–93.6) | 8.8 | 5.1 (0.0–100.0) |
| Estrogen only | 0.8 | 0.60 (0.0–5.2) | 17.8 | 11.0 (0.0–71.6) | 81.4 | 88.7 (25.1–100.0) | 18.6 | 11.3 (0.0–74.9) | 6.5 | 4.0 (0.0–87.1) |
| Combined estrogen and progesterone | 0.8 | 0.32 (0.0–9.1) | 22.9 | 14.7 (0.1–86.7) | 76.3 | 85.1 (12.2–99.9) | 23.7 | 14.9 (0.1–87.8) | 6.3 | 2.5 (0.0–57.6) |
| P value | 0.04 | 0.54 | 0.61 | 0.61 | < 0.0001 | |||||
| Menopausal hormone therapy type-former user | ||||||||||
| Nonuser | 1.2 | 0.53 (0.0–18.4) | 18.6 | 12.6 (0.0–91.3) | 80.3 | 86.2 (6.4–100.0) | 19.7 | 13.8 (0.0–93.6) | 8.8 | 5.1 (0.0–100.0) |
| Estrogen only | 1.2 | 0.60 (0.0–6.3) | 19.4 | 15.8 (0.02–68.4) | 79.5 | 83.3 (30.5–100.0) | 20.5 | 16.7 (0.0–69.5) | 8.0 | 5.5 (0.0–42.7) |
| Combined estrogen and progesterone | 1.2 | 0.51 (0.0–6.2) | 21.0 | 9.8 (0.0–90.6) | 77.8 | 89.7 (9.3–100.0) | 22.2 | 10.3 (0.0–90.7) | 6.8 | 4.2 (0.0–55.9) |
| P value | 0.68 | 0.76 | 0.77 | 0.77 | 0.33 | |||||
| Family history of breast cancer | ||||||||||
| Negative | 2.1 | 0.92 (0.0–53.4) | 25.4 | 18.0 (0.0–95.8) | 72.5 | 80.5 (2.8–100.0) | 27.5 | 19.5 (0.0–97.2) | 9.1 | 5.8 (0.0–100.0) |
| Positive | 1.9 | 0.78 (0.0–70.4) | 22.0 | 15.3 (0.0–93.3) | 76.0 | 83.0 (5.3–100.0) | 24.0 | 17.0 (0.0–94.7) | 9.7 | 6. 2 (0.0–92.9) |
| P value | 0.40 | 0.002 | 0.003 | 0.003 | 0.06 | |||||
Asian/Other category comprised women who self-identified as Asian, Chinese, Filipino, Japanese, “Other” Asian, Asian/Native Hawaiian or Pacific Islander, etc. Parity: parous = women who had previously been pregnant, irrespective of the outcome; nulliparous = women who had never been pregnant. NLB = Number of Live Births (0 = previous pregnancies did not result in a live birth). P values were obtained using Kruskal–Wallis’s test. P values <0.05 were considered statistically significant and are indicated using bold fonts