Table 1.
Characteristics of breast cancer cases and controls.a
| Risk factors | Controls n = 1416 | Luminal n = 898 | HER2-enriched n = 55 | Triple-negative n = 303 | P-valueb |
|---|---|---|---|---|---|
| Age, years | 47.96 (10.07) | 47.73 (10.93) | 48.62 (8.97) | 49.54 (10.74) | 0.06 |
| BMI, kg/m2 | 22.32 (2.66) | 23.01 (2.88) | 22.65 (2.26) | 23.20 (3.03) | <0.001 |
| Age at menarche | 14.28 (1.68) | 14.27 (1.82) | 14.87 (1.78) | 14.49 (1.84) | 0.02 |
| Age at first live birth | 25.04 (2.68) | 24.50 (2.78) | 24.51 (2.50) | 24.18 (2.69) | <0.001 |
| Age at menopause | 48.98 (2.97) | 48.97 (4.29) | 49.24 (4.12) | 48.52 (4.35) | 0.44 |
| Menopause status | |||||
| No | 831 (58.8) | 554 (61.7) | 30 (54.5) | 154 (50.8) | 0.01 |
| Yes | 585 (41.2) | 344 (38.3) | 25 (45.5) | 149 (49.2) | |
| Parity | |||||
| 0 | 39 (2.8) | 28 (3.1) | 0 (0.0) | 15 (5.0) | 0.11 |
| ≥1 | 1377 (97.2) | 870 (96.9) | 55 (100.0) | 288 (95.0) | |
| Breastfeedingc | |||||
| No | 95 (6.9) | 49 (5.6) | 5 (9.1) | 21 (7.3) | 0.51 |
| Yes | 1282 (93.1) | 821 (94.4) | 50 (90.9) | 267 (92.7) | |
| Family history of breast cancer | |||||
| No | 1391 (98.2) | 860 (95.8) | 54 (98.2) | 290 (95.7) | 0.002 |
| Yes | 25 (1.8) | 38 (4.2) | 1 (1.8) | 13 (4.3) | |
BMI, body mass index.
a
Mean (standard deviation): age, BMI, age at menarche, age at fist live birth, age at menopause. n (%): menopause status, parity, breast feeding, tumor subtype, family history of breast cancer.
b
One-way analysis of variance: age, BMI, age at menarche, age at first live birth, age at menopause; Chi-square test: menopause status; Fisher's exact test: parity, breast feeding, family history of breast cancer.
c
Among parous women.