Table 2.
Distribution of Breast Cancer Risk Factors Among all Women and by Education Among EPIC Women.
| All women | Education
|
||||||
|---|---|---|---|---|---|---|---|
| Primary | Vocational secondary | Other secondary | University or post-secondary vocational | ||||
| Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | Mean (±SD) | |||
| Age at recruitment | 50.3 (±10.2) | 54.1 (±8.9) | 50.2 (±9.5) | 47.7 (±10.2) | 46.2 (±10.7) | ||
| Number of full term pregnancies | 2.3 (±1.0) | 2.5 (±1.2) | 2.2 (±0.9) | 2.2 (±1.0) | 2.1 (±0.9) | ||
| Age at first full term pregnancy | 24.8 (±4.4) | 23.7 (±4.2) | 24.3 (±4.2) | 25.7 (±4.2) | 27.3 (±4.6) | ||
| Age at menopausea | 48.7 (±4.7) | 48.6 (±4.8) | 48.8 (±4.7) | 48.8 (±4.7) | 49.0 (±4.6) | ||
| Height (cm) | 162.5 (±7.0) | 159.1 (±6.8) | 164.0 (±6.2) | 164.1 (±6.6) | 164.5 (±6.4) | ||
| Median (IQ range) | Median (IQ range) | Median (IQ range) | Median (IQ range) | Median (IQ range) | |||
| Alcohol consumption in g/day | 3.2 (10.1) | 1.4 (7.4) | 4.1 (9.9) | 3.7 (10.2) | 6.2 (11.5) | ||
| NI | NIS | % | % | % | % | % | |
| Duration of breast feeding | |||||||
| Nulliparous | 664 | 63 | 16.7 | 8.6 | 14.6 | 20.2 | 30.6 |
| Parous: Never breastfed | 460 | 53 | 9.7 | 11.2 | 10.8 | 8.8 | 6.1 |
| Parous: 0–6 months | 1376 | 135 | 28.4 | 30.0 | 32.4 | 24.6 | 23.1 |
| Parous: 6–12 months | 836 | 93 | 18.7 | 21.0 | 19.0 | 17.6 | 15.6 |
| Parous: >12 months | 957 | 72 | 22.9 | 26.5 | 18.7 | 24.0 | 21.7 |
| Parous: Missing information | 176 | 17 | 3.6 | 2.7 | 4.5 | 4.8 | 2.9 |
| Age at menarche | |||||||
| <12 | 577 | 67 | 14.1 | 13.9 | 12.6 | 15.3 | 15.9 |
| 12–14 | 3032 | 294 | 67.8 | 65.7 | 67.5 | 69.6 | 70.0 |
| >14 | 788 | 63 | 16.9 | 19.4 | 18.3 | 14.0 | 13.2 |
| Missing | 72 | 9 | 1.2 | 1.1 | 1.6 | 1.1 | 0.9 |
| Duration of use of oral contraceptive | |||||||
| Never | 1928 | 188 | 41.4 | 60.6 | 31.7 | 34.6 | 28.0 |
| 1 year or less | 473 | 42 | 11.0 | 10.6 | 10.4 | 12.5 | 11.2 |
| 2–4 years | 567 | 49 | 13.2 | 9.4 | 14.2 | 15.4 | 16.3 |
| 5–9 years | 501 | 48 | 12.2 | 7.2 | 14.1 | 13.4 | 17.0 |
| 10–14 years | 381 | 44 | 8.6 | 5.1 | 11.1 | 8.6 | 11.3 |
| 15+ years | 403 | 40 | 7.7 | 4.7 | 11.1 | 6.3 | 9.0 |
| Missing | 216 | 22 | 5.9 | 2.4 | 7.4 | 9.2 | 7.2 |
| Duration of use of hormonal replacement therapy | |||||||
| No treatment | 2615 | 257 | 70.7 | 72.9 | 63.2 | 76.4 | 72.9 |
| 1 year or less | 361 | 36 | 6.8 | 7.3 | 7.5 | 6.0 | 5.4 |
| 2–4 years | 408 | 40 | 6.6 | 5.5 | 8.6 | 6.3 | 5.9 |
| 5–9 years | 357 | 26 | 4.4 | 3.7 | 6.2 | 3.6 | 3.7 |
| 10+ years | 225 | 18 | 2.4 | 2.4 | 3.5 | 1.7 | 1.5 |
| Missing | 503 | 56 | 9.1 | 8.2 | 11.1 | 5.9 | 10.6 |
| BMI (kg/m2) | |||||||
| <18.5 | 47 | 4 | 1.5 | 0.7 | 1.5 | 1.9 | 2.5 |
| 18.5–24 | 2261 | 227 | 51.6 | 33.9 | 55.9 | 61.7 | 67.3 |
| 25–29 | 1501 | 143 | 31.9 | 39.7 | 31.1 | 27.6 | 23.4 |
| 30+ | 660 | 59 | 15.0 | 25.7 | 11.5 | 8.8 | 6.8 |
| Total physical activity | |||||||
| Inactive | 612 | 58 | 11.4 | 4.0 | 13.9 | 12.2 | 20.1 |
| Moderately inactive | 1071 | 102 | 21.6 | 17.4 | 22.1 | 20.3 | 29.5 |
| Moderately active | 1826 | 200 | 41.6 | 57.4 | 34.0 | 33.6 | 31.9 |
| Active | 444 | 66 | 9.7 | 10.9 | 10.2 | 7.9 | 8.3 |
| Missing | 516 | 7 | 15.7 | 10.3 | 19.8 | 26.0 | 10.2 |
BMI body mass index; IQ range inter-quartile range; NI=number of invasive breast cancers; NIS=number of in situ breast cancers SD standard deviation;
a
Among postmenopausal women