Table 1. Basic demographic characteristics and clinical features for breast cancer cases and cancer free-controls.
| Characteristics | Cases (n = 969) no.(%) | Controls (n = 970) no.(%) | P |
|---|---|---|---|
| Age, y (mean ± SD) | 46.9 ± 10.2 | 47.2 ± 11.0 | 0.556 |
| BMI, kg/m2 (mean ± SD) | 22.5 ± 2.6 | 23.1 ± 3.1 | <0.001 |
| Age at menarche, y (mean ± SD) | 15.2 ± 1.7 | 15.5 ± 1.7 | <0.001 |
| Menopausal status | 0.053 | ||
| Premenopausal | 620 | 624 | |
| Postmenopausal | 342 | 327 | |
| Unnatural menopausea | 7 | 19 | |
| Age at menopause, y (mean ± SD) | 50.2 ± 3.0 | 50.3 ± 3.0 | 0.673 |
| Age at first live birth, y (mean ± SD) | 25.0 ± 3.6 | 24.2 ± 3.3 | <0.001 |
| Family history of breast cancer | <0.001 | ||
| Yes | 75 | 12 | |
| No | 894 | 958 | |
| Previous benign breast disease | 0.079 | ||
| Yes | 40 | 26 | |
| No | 929 | 944 | |
| Tumor size | |||
| >2 cm | 584 (60.3) | ||
| ≤2 cm | 385 (39.7) | ||
| Lymph node involvement | |||
| Yes | 490 (50.6) | ||
| No | 479 (49.4) | ||
| Estrogen receptor (ER) status | |||
| Positive | 644 (66.5) | ||
| Negative | 325 (33.5) | ||
| Progestrone receptor (PR) status | |||
| Positive | 566 (58.4) | ||
| Negative | 403 (41.6) | ||
| HER-2 status | |||
| Positive | 315 (32.5) | ||
| Negative | 654 (67.5) | ||
| Molecular subtype | |||
| Luminal type | 644 (66.4) | ||
| HER-2 overexpression | 149 (15.4) | ||
| TNBCb | 176 (18.2) | ||
| Relapse | |||
| Yes | 337 (34.8) | ||
| No | 632 (65.2) | ||
| Death | |||
| Yes | 217 (22.4) | ||
| No | 752 (77.6) |
aUnnatural menopause consists of hysterectomy operation and other status.
bTNBC for triple negative breast cancer.