Table 1 Characteristics of the breast cancer case – control sample in the European Prospective into Cancer-Norfolk cohort
| Â | Cases (n = 237) | Controls (n = 952) | P valuea |
|---|---|---|---|
Age (years) | 58.5 (8.6) | 58.7 (8.9) | 0.791 |
Weight (kg) | 69.2 (11.4) | 67.7 (11.2) | 0.068 |
Energy intake (kcal/day) | 1745.9 (386.6) | 1678.6 (385.2) | 0.022 |
Fat intake (g/day) | 66.5 (19.7) | 63.5 (20.1) | 0.038 |
Alcohol intake (g/day) | 8.6 (12.1) | 7.8 (11.2) | 0.179 |
Oestradiol (pmol/l)b | 173.1 (341.3) | 136.9 (259.4) | 0.066 |
Age at menarche (years) | 12.8 (1.6) | 13.0 (1.5) | 0.058 |
Family history of breast cancer: yes | 23 (10%) | 74 (8%) | 0.216 |
Breastfed children: yes | 155 (65%) | 617 (65%) | 0.865 |
Number of children | Â | Â | Â |
   0 | 38 (16%) | 117 (12%) | 0.174 |
   1 | 26 (11%) | 134 (14%) |  |
   2 | 103 (43%) | 398 (42%) |  |
   3 | 57 (24%) | 218 (23%) |  |
   4+ | 13 (6%) | 85 (9%) |  |
Menopausal statusc | Â | Â | Â |
   Premenopausal | 28 (12%) | 123 (13%) | 0.569 |
   Perimenopausal | 15 (6%) | 51 (5%) |  |
   Postmenopausal 1 | 57 (24%) | 195 (21%) |  |
   Postmenopausal 2 | 137 (58%) | 583 (61%) |  |
Menopausal hormone therapy use | Â | Â | Â |
   Current | 63 (27%) | 207 (22%) | 0.256 |
   Former | 30 (13%) | 118 (12%) |  |
   Never | 144 (61%) | 627 (66%) |  |
Oral contraceptive use | Â | Â | Â |
   Current | 9 (4%) | 13 (1%) | 0.041 |
   Former | 98 (41%) | 419 (44%) |  |
   Never | 130 (55%) | 520 (55%) |  |
Social class | Â | Â | Â |
   Professional/manager | 105 (45%) | 405 (42%) | 0.620 |
   Skilled nonmanual | 46 (20%) | 171 (18%) |  |
   Skilled manual | 51 (22%) | 197 (21%) |  |
   Semi-skilled/nonskilled | 20 (9%) | 112 (12%) |  |
   Missing/unclassified | 15 (4%) | 67 (7%) |  |
Smoking status | Â | Â | Â |
   Current | 26 (11%) | 94 (10%) | 0.822 |
   Former | 70 (30%) | 297 (32%) |  |
   Never | 137 (59%) | 550 (59%) |  |