TABLE 1.
Descriptive characteristics of breast cancer cases and controls, Roswell Park Cancer Institute Data Bank and BioRepository, 2003–20141
| Premenopausal | Postmenopausal | |||
|---|---|---|---|---|
| Cases (n = 601) | Controls (n = 470) | Cases (n = 1256) | Controls (n = 732) | |
| Age, y | 45.5 ± 5.9* | 44.7 ± 5.9 | 64.6 ± 8.9** | 62.3 ± 8.6 |
| BMI, kg/m2 | 27.0 ± 6.3 | 27.4 ± 6.0 | 29.2 ± 6.4 | 28.4 ± 6.1 |
| Age at menarche, y | ||||
| ≤11 | 96 (16.0) | 94 (20.0) | 259 (20.6) | 146 (20.0) |
| 12 | 202 (33.6) | 153 (32.6) | 390 (31.1) | 230 (31.4) |
| 13 | 177 (29.5) | 123 (26.2) | 356 (28.3) | 212 (29.0) |
| 14 | 60 (10.0) | 61 (13.0) | 140 (11.2) | 81 (11.1) |
| 15 | 36 (6.0) | 20 (4.3) | 57 (4.5) | 29 (4.0) |
| ≥16 or never had period | 30 (5.0) | 19 (4.0) | 54 (4.3) | 34 (4.6) |
| Age at first birth, y | ||||
| Nulliparous | 133 (22.1)* | 131 (27.9) | 203 (16.2)* | 134 (18.3) |
| ≤19 | 53 (8.8) | 57 (12.1) | 205 (16.3) | 80 (10.9) |
| 20–24 | 149 (24.8) | 100 (21.3) | 466 (37.1) | 258 (35.3) |
| 25–29 | 140 (23.3) | 102 (21.7) | 250 (19.9) | 175 (23.9) |
| 30–34 | 99 (16.5) | 58 (12.3) | 99 (7.9) | 64 (8.7) |
| ≥35 | 27 (4.5) | 22 (4.7) | 33 (2.6) | 21 (2.9) |
| Smoking status | ||||
| Never | 353 (58.7)** | 262 (55.7) | 613 (48.8)* | 387 (52.9) |
| Former | 166 (27.6) | 144 (30.6) | 531 (42.3) | 300 (41.0) |
| Current | 82 (13.6) | 64 (13.6) | 112 (8.9) | 45 (6.2) |
| Family history of breast cancer | ||||
| No | 471 (78.4)** | 403 (85.7) | 950 (75.6) | 603 (82.4) |
| Yes | 130 (21.6) | 67 (14.3) | 306 (24.4) | 129 (17.6) |
1
Values are means ± SDs or n (%). Excludes women with implausible dietary data. Differences between cases and controls assessed with Student's t test for continuous variables and Pearson's chi-square for categorical variables. *P < 0.05; **P < 0.01.