Table 1.
Descriptive characteristics of breast cancer cases and controls
| Host factors | RPCI Breast Cancer Study | LCCC Breast Cancer Study | ||||
|---|---|---|---|---|---|---|
| Cases (n=152) | Controls (n=176) | p-value | Cases (n=140) | Controls (n=159) | p-value | |
| Age (years), mean (SD) | 56.1 (12.3) | 56.8 (12.8) | 0.62 | 52.7 (10.6) | 53.3 (9.9) | 0.66 |
| BMI (kg/m2), mean (SD) | 27.9 (8.2) | 27.3 (5.9) | 0.39 | 27.1 (6.6) | 27.3 (6.3) | 0.86 |
| Race, N (%) | ||||||
| Caucasian | 144 (94.7) | 162 (92.1) | 104 (74.2) | 118 (74.2) | ||
| African American | 5 (3.3) | 12 (6.8) | 28 (20.0) | 34 (21.4) | ||
| Other | 3 (2.0) | 2 (1.1) | 0.30 | 8 (5.7) | 7 (4.4) | 0.85 |
| Menopausal status, N (%) | ||||||
| Pre/perimenopausal | 63 (41.5) | 57 (32.4) | 56 (42.8) | 67 (42.4) | ||
| Postmenopausal | 89 (58.6) | 119 (67.6) | 0.09 | 75 (57.3) | 91 (57.6) | 0.95 |
| Cigarette smoking status, N (%) | ||||||
| Never | 82 (53.9) | 89 (50.6) | 81 (60.0) | 93 (58.9) | ||
| Ever | 70 (46.0) | 87 (49.5) | 0.54 | 54 (40.0) | 65 (41.1) | 0.84 |
| Alcohol consumption, N (%) | ||||||
| Never | 42 (27.6) | 33 (18.8) | 15 (11.5) | 12 (7.6) | ||
| Ever | 110 (72.4) | 143 (81.2) | 0.06 | 116 (88.6) | 147 (92.5) | 0.23 |
| HRT§ use, N (%) | ||||||
| Never | 41 (26.9) | 64 (36.4) | 86 (65.7) | 94 (59.1) | ||
| Ever | 108 (71.1) | 112 (63.6) | 0.09 | 45 (34.4) | 65 (40.9) | 0.25 |
| Education, N (%) | ||||||
| High school or less | 53 (34.9) | 31 (17.6) | 18 (13.4) | 9 (5.7) | ||
| Post high school – 4 years college | 99 (65.1) | 145 (82.4) | <0.01 | 60 (44.8) | 73 (45.9) | |
| > 4 years college | 56 (41.8) | 77 (48.4) | 0.06 | |||
| Family history of cancer^ | ||||||
| No | 62 (40.8) | 47 (26.7) | 50 (39.7) | 73 (46.5) | ||
| Yes | 90 (59.2) | 129 (73.3) | 0.007 | 76 (60.3) | 84 (53.5) | 0.25 |
| Household income†, N (%) | ||||||
| Low | 72 (47.4) | 66 (37.5) | 46 (32.9) | 56 (35.2) | ||
| High | 63 (41.5) | 88 (50.0) | 51 (36.4) | 77 (48.4) | ||
| Missing data | 17 (11.2) | 22 (12.5) | 0.18 | 43 (30.7) | 26 (16.4) | 0.01 |
§
hormone replacement therapy
^
defined as any cancer in the first degree blood relatives
†
RPCI study household income low < $50,000, high ≥ $50,000; LCCC study household income low ≤ $100,000 and high > $100,000.