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Parous women: multivariate analysis of the effects of risk factors for BRCA2-positive cases and BRCA2-negative cases separately |
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| BRCA2-positive cases (n = 100) versus matched controls (n = 1000) |
BRCA2-negative cases (n versus = 361) matched controls (n = 1000) |
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| Risk factor |
Odds ratio (95% confidence interval) |
P value |
Odds ratio (95% confidence interval) |
P value |
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| Age at menarche |
0.92 (0.74–1.14) |
0.430 |
0.87 (0.77–0.99) |
0.030 |
| Age at first birth |
1.01 (0.93–1.10) |
0.738 |
1.02 (0.97–1.07) |
0.352 |
| Number of births |
1.17 (0.95–1.43)* |
0.132 |
0.87 (0.75–1.00)* |
0.057 |
| Total duration of breast-feeding (unit, 6 months) |
0.96 (0.91–1.01)** |
0.141 |
1.01 (0.98–1.03)** |
0.579 |
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Odds ratios are presented per unit increment of the variables. * P = 0.007, odds ratio = 1.49 for the interaction between the number of births and the mutation status. ** P = 0.045, odds ratio = 0.93 for the interaction between the total duration of breast feeding and the mutation status. When testing for interaction between the other variables and the mutation status, P > 0.4. | ||||
Tryggvadottir et al. Breast Cancer Res 2003 5:R121 doi:10.1186/bcr619 |
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