|
Comparison of age at menarche and reproductive factors between BRCA2-positive cases, BRCA2-negative cases and controls |
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| BRCA2-positive cases (n = 100) |
BRCA2-negative cases (n = 361) |
Matched controls (n = 1000) |
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|
|
|
|
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| Risk factor |
% distribution |
Mean |
% distribution |
Mean |
% distribution |
Mean |
|
|
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| Age at menarche |
n = 85 (85%)* |
n = 313 (87%)* |
n = 860 (86%)* |
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| < 13 years |
25.9 |
13.2 years |
31.3 |
13.1 years |
27.4 |
13.3 years |
| 13 years |
35.3 |
29.1 |
28.9 |
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| > 13 years |
38.8 |
39.6 |
43.6 |
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| Parous |
n = 99 (99%) |
n = 355 (98%) |
n = 991 (99%) |
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| Yes |
89.9 |
88.2 |
93.0 |
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| No |
10.0 |
11.8 |
7.0 |
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| Parous women |
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| Age at first birth |
n = 85 (96%) |
n = 300 (96%) |
n = 880 (95%) |
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| < 20 years |
16.5 |
22.2 years |
22.3 |
23.0 years |
25.0 |
22.3 years |
| 20–29 years |
80.0 |
69.3 |
69.6 |
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| > 29 years |
3.5 |
8.3 |
5.4 |
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| Number of births |
n = 89 (100%) |
n = 313 (100%) |
n = 922 (100%) |
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| 1–2 |
32.6 |
3.3 births |
40.9 |
3.0 births |
39.7 |
3.2 births |
| 3–4 |
46.1 |
45.7 |
42.5 |
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| 5+ |
21.3 |
13.4 |
17.8 |
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| Total duration of breastfeeding |
n = 58 (65%) |
n = 209 (67%) |
n = 640 (69%) |
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| 0 months |
1.7 |
8.5 months |
2.9 |
9.2 months |
1.9 |
9.3 months |
| < 1 months |
1.7 |
5.3 |
6.9 |
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| 1–6 months |
44.8 |
37.3 |
38.4 |
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| 7–12 months |
29.3 |
31.1 |
28.8 |
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| 13–24 months |
19.0 |
18.7 |
17.2 |
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| > 24 months |
3.4 |
4.8 |
6.9 |
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|
*Percentages with recorded responses for each item. | ||||||
Tryggvadottir et al. Breast Cancer Res 2003 5:R121 doi:10.1186/bcr619 |
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