From: Nighttime eating and breast cancer among Chinese women in Hong Kong
Variables | Case participants (n = 922) | Controls (n = 913) |
---|---|---|
Age at interview (years) | 56.0 ± 11.8 | 53.7 ± 11.7 |
Age at menarche (years) | 13.6 ± 2.0 | 13.8 ± 2.3 |
Age at first birth (years) | 26.4 ± 4.9 | 25.6 ± 4.7 |
BMI (kg/m2) | 23.5 ± 3.7 | 23.0 ± 3.9 |
BMIa | ||
 Underweight (<18.5) | 44 (4.8) | 74 (8.1) |
 Normal (18.5–22.9) | 329 (35.7) | 350 (38.3) |
 Overweight (23.0–24.9) | 160 (17.4) | 157 (17.2) |
 Obesity I (25–29.9) | 205 (22.2) | 162 (17.7) |
 Obesity II (≥30) | 45 (4.9) | 40 (4.4) |
 Unknown | 139 (15.1) | 130 (14.2) |
First-degree family cancer history | ||
 Yes | 323 (35.0) | 246 (26.9) |
 No | 572 (62.0) | 652 (71.4) |
 Unknown | 27 (2.9) | 15 (1.6) |
Family history of breast cancer | ||
 Yes | 70 (7.6) | 28 (3.1) |
 No | 825 (89.5) | 870 (95.3) |
 Unknown | 27 (2.9) | 15 (1.6) |
Parity, number of births | ||
 0 | 164 (17.8) | 154 (16.8) |
 1–2 | 484 (52.5) | 473 (51.8) |
 ≥3 | 228 (24.7) | 269 (29.5) |
 Unknown | 46 (5.0) | 17 (1.9) |
Smoking | ||
 Ever | 63 (6.8) | 69 (7.6) |
 Never | 859 (93.2) | 844 (92.4) |
Alcohol drinking | ||
 Yes | 47 (5.1) | 41 (4.5) |
 No | 875 (94.9) | 872 (95.5) |
Shift work | ||
 Yes | 111 (12.0) | 150 (16.4) |
 No | 771 (83.6) | 737 (80.7) |
 Unknown | 40 (4.3) | 26 (2.8) |
Histological type | ||
 Ductal | 809 (87.7) |  |
 Lobular | 30 (3.3) |  |
 Mucinous | 36 (3.9) |  |
 Medullary | 3 (0.3) |  |
 Others | 44 (4.8) |  |
Tumor stage | ||
 Stage I | 240 (31.8) |  |
 Stage II | 298 (39.4) |  |
 Stage III | 96 (12.7) |  |
 Stage IV | 42 (5.6) |  |
 Un-staged | 79 (10.5) |  |
Estrogen receptor status | ||
 Positive | 601 (76.7) |  |
 Negative | 183 (23.3) |  |
Progesterone receptor status | ||
 Positive | 450 (59.5) |  |
 Negative | 306 (40.5) |  |
C-erbB2/HER2 | ||
 Negative(IHC score 0/1) | 351 (45.8) |  |
 Weakly positive (IHC score 2) | 268 (35.0) |  |
 Positive (IHC score 3) | 147 (19.2) |  |