Table 1. Characteristics of study population in the Komen Tissue Bank, stratified by race and menopausal status, N=998.
| Characteristics | Premenopausal | Postmenopausal | ||||
|---|---|---|---|---|---|---|
|
|
||||||
| Caucasians (N=544) | African Americans (N=203) | P-value | Caucasians (N=171) | African Americans (N=80) | P-value | |
| N (%) | N (%) | |||||
| Age | ||||||
| <30 years | 164 (30.2) | 45 (22.2) | 0.13 | 0 (0.0) | 0 (0.0) | 0.58 |
| 30-39 years | 173 (31.8) | 78 (38.4) | 5 (2.9) | 2 (2.5) | ||
| 40-49 years | 162 (30.0) | 65 (32.0) | 23 (13.5) | 11 (13.8) | ||
| 50-59 years | 45 (8.3) | 15 (7.4) | 83 (48.5) | 32 (40.0) | ||
| ≥60 years | 0 (0.0) | 0 (0.0) | 60 (35.1) | 35 (43.8) | ||
| Menstrual phase | ||||||
| Follicular | 178 (32.7) | 63 (31.0) | 0.49 | NA | NA | NA |
| Peri-ovulatory | 72 (13.2) | 21 (10.3) | NA | NA | ||
| Luteal | 142 (26.1) | 52 (25.6) | NA | NA | ||
| Unknown | 152 (27.9) | 67 (33.0) | NA | NA | ||
| Body mass index | ||||||
| <25 kg/m2 | 197 (36.2) | 36 (17.7) | <0.0001 | 47 (27.5) | 13 (16.3) | 0.15 |
| 25.0-29.9 kg/m2 | 131 (24.1) | 51 (25.1) | 46 (26.9) | 25 (31.3) | ||
| ≥30 kg/m2 | 216 (39.7) | 116 (57.1) | 78 (45.6) | 42 (52.5) | ||
| Height | ||||||
| <160.0 cm | 83 (15.3) | 37 (18.2) | 0.73 | 36 (21.1) | 17 (21.3) | 0.99 |
| 160.0-164.9 cm | 154 (28.3) | 58 (28.6) | 60 (35.1) | 29 (36.3) | ||
| 165.0-169.9 cm | 156 (28.7) | 52 (25.6) | 44 (25.7) | 19 (23.8) | ||
| ≥170 cm | 151 (27.8) | 56 (27.6) | 31 (18.1) | 15 (18.8) | ||
| Age at menarche | ||||||
| ≤12 years | 276 (50.7) | 127 (62.6) | 0.01 | 79 (46.2) | 41 (51.3) | 0.70 |
| 13 years | 150 (27.6) | 40 (19.7) | 46 (26.9) | 21 (26.3) | ||
| ≥14 years | 118 (21.7) | 36 (17.7) | 46 (26.9) | 18 (22.5) | ||
| Parity/age at first birth | ||||||
| Nulliparous | 272 (50.0) | 83 (40.9) | 0.0002 | 30 (17.5) | 15 (18.8) | 0.008 |
| Parous, <25 years | 94 (17.3) | 63 (31.0) | 56 (32.8) | 41 (51.3) | ||
| Parous, ≥25 years | 178 (32.7) | 57 (28.1) | 85 (49.7) | 24 (30.0) | ||
| Breastfeeding (among parous women) | ||||||
| Never | 56 (20.6) | 36 (30.0) | 0.04 | 45 (31.9) | 31 (47.7) | 0.03 |
| Ever | 216 (79.4) | 84 (70.0) | 96 (68.1) | 34 (52.3) | ||
| Years since menopause | ||||||
| <5 years | NA | NA | NA | 48 (28.1) | 21 (26.3) | 0.02 |
| 5-10 years | NA | NA | 42 (24.6) | 15 (18.8) | ||
| 11-15 years | NA | NA | 50 (29.2) | 21 (26.3) | ||
| >15 years | NA | NA | 18 (10.5) | 21 (26.3) | ||
| Unknown | NA | NA | 13 (7.6) | 2 (2.5) | ||
| Use of hormone therapy (among postmenopausal women) | ||||||
| Never | NA | NA | NA | 107 (62.6) | 58 (72.5) | 0.12 |
| Past | NA | NA | 64 (37.4) | 22 (27.5) | ||
| Smoking status | ||||||
| Never | 380 (69.9) | 186 (91.6) | <0.0001 | 112 (65.5) | 44 (55.0) | 0.23 |
| Former | 113 (20.8) | 12 (5.9) | 50 (29.2) | 32 (40.0) | ||
| Current | 51 (9.4) | 5 (2.5) | 9 (5.3) | 4 (5.0) | ||
| Current alcohol consumption | ||||||
| 0 drink/wk | 148 (27.2) | 81 (39.9) | <0.0001 | 65 (38.0) | 38 (47.5) | 0.15 a |
| <7 drinks/wk | 349 (64.2) | 120 (59.1) | 88 (51.5) | 42 (52.5) | ||
| ≥7 drinks/wk | 47 (8.6) | 2 (1.0) | 18 (10.5) | 0 (0.0) | ||
| First-degree relative with breast cancer | ||||||
| No | 439 (80.7) | 179 (88.2) | 0.02 | 130 (76.0) | 60 (75.0) | 0.86 |
| Yes | 105 (19.3) | 24 (11.8) | 41 (24.0) | 20 (25.0) | ||
| Percent fat on H&E slide | ||||||
| ≤75% | 264 (48.5) | 69 (34.0) | 0.0004 | 57 (33.3) | 21 (26.3) | 0.26 |
| >75% | 280 (51.5) | 134 (66.0) | 114 (66.7) | 59 (73.8) | ||
| Median (IQR) | Median (IQR) | |||||
| IGF measures | ||||||
| IGF-I | 151 (118-190) | 148 (118-184) | 108 (88-125) | 110 (95-140) | ||
| IGFBP-3 | 4919 (4417-5459) | 4306 (3787-4780) | 4483 (3876-4962) | 4080 (3676-4542) | ||
| IGF-I:IGFBP-3 molar ratio | 0.11 (0.09-0.14) | 0.13 (0.10-0.15) | 0.09 (0.08-0.10) | 0.10 (0.09-0.12) | ||
| Lobular involution measures among women with ≥1 observed TDLU | ||||||
| Number of TDLU | 8 (3-17) | 7 (3-14) | 5 (3-12) | 5 (2-10) | ||
| Number of acini/TDLU | 13 (8-20) | 16 (9-26) | 7 (4-10) | 8 (4-14) | ||
| Product of TDLU count and acini count/TDLU | 112 (35-252) | 128 (39-280) | 28 (12-76) | 35 (12-88) | ||
Abbreviations: H & E=hematoxylin & eosin, IGF-I=insulin-like growth factor-I, IGFBP-3=insulin-like growth factor binding protein-3, IQR=interquartile range, NA=not applicable, TDLU=terminal duct lobular unit
Note: P-values were estimated using chi-square test.
a
P-values were estimated for 0 drink/wk and >0 drink/wk categories