Table 1.
Characteristics at blood draw of 1215 participants of the Nurses’ Health Study who were included in this nested case-control study population and information on cancer grade among women with invasive breast cancer
| Cases (n = 405) |
Controls (n = 810) |
|
|---|---|---|
| Age diagnosis (y), mean (sd) | 46.0 (4.6) | - |
| Age blood draw (y), mean (sd) | 44.8 (4.1) | 44.6 (4.0) |
| Log10 (Leptin) (pg/ml), mean (sd) | 4.17 (0.3) | 4.17 (0.3) |
| Height (cm), mean (sd) | 165.6 (6.5) | 165.1 (6.5) |
| BMI at age 18 (kg/m2), mean (sd) | 20.9 (2.9) | 21.1 (2.9) |
| BMI at blood draw (kg/m2), mean (sd) | 25.4 (5.2) | 25.8 (5.9) |
| Age at menarche (y), mean (sd) | 12.4 (1.4) | 12.4 (1.4) |
| Parity, median (interquartile range) | 2 (1–2) | 2 (1–3) |
| Age at first birth (y), mean (sd) | 26.8 (4.6) | 26.2 (4.4) |
| Family history n (%) | ||
| Yes | 73. (18.0) | 79 (9.8) |
| No | 332 (82.0) | 731 (90.3) |
| Benign breast disease n (%) | ||
| Yes | 101 (24.9) | 148 (18.3) |
| No | 304 (75.1) | 662 (81.7) |
| Grade, n (%a) | ||
| Total number = 267 | ||
| Well differentiated | 42 (15.7) | |
| Moderately differentiated | 123 (46.1) | |
| Poorly differentiated | 102 (38.2) | |
a
Percentage based on 267 cases with this information