From: Breastfeeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers
Breastfeeding duration | N (cases/controls) | Univariate OR (95% CI) | P | Multivariate1 OR (95% CI) | P |
---|---|---|---|---|---|
All subjects | 1,665/1,665 | Â | Â | Â | Â |
Never | 389/327 | 1.00 (reference) | Â | 1.00 (reference) | Â |
Ever | 1,276/1,338 | 0.79 (0.67 to 0.94) | 0.007 | 0.81 (0.68 to 0.97) | 0.02 |
> 0 to ≤ 12 months | 846/845 | 0.83 (0.69 to 0.99) | 0.04 | 0.84 (0.70 to 1.02) | 0.08 |
> 12 to ≤ 24 months | 285/318 | 0.72 (0.58 to 0.90) | 0.005 | 0.73 (0.58 to 0.93) | 0.01 |
> 24 months | 145/175 | 0.65 (0.49 to 0.86) | 0.003 | 0.66 (0.49 to 0.89) | 0.007 |
Per year | Â | 0.90 (0.84 to 0.97) | 0.008 | 0.87 (0.79 to 0.95) | 0.002 |
BRCA1 | 1,243/1,343 | Â | Â | Â | Â |
Never | 267/213 | 1.00 (reference) | Â | 1.00 (reference) | Â |
Ever | 976/1,030 | 0.74 (0.61 to 0.92) | 0.005 | 0.76 (0.61 to 0.95) | 0.02 |
> 0 to ≤ 12 months | 669/658 | 0.79 (0.64 to 1.00) | 0.03 | 0.81 (0.64 to 1.01) | 0.06 |
> 12 to ≤ 24 months | 212/236 | 0.68 (0.52 to 0.88) | 0.004 | 0.68 (0.52 to 0.91) | 0.008 |
> 24 months | 94/136 | 0.50 (0.35 to 0.70) | < 0.0001 | 0.51 (0.35 to 0.74) | 0.0003 |
Per year | Â | 0.84 (0.77 to 0.93) | 0.0003 | 0.81 (0.73 to 0.91) | 0.002 |
BRCA2 | 422/422 | Â | Â | Â | Â |
Never | 122/114 | 1.00 (reference) | Â | 1.00 (reference) | Â |
Ever | 300/308 | 0.91 (0.67 to 1.23) | 0.53 | 0.90 (0.64 to 1.25) | 0.51 |
> 0 to ≤ 12 months | 177/187 | 0.89 (0.64 to 1.23) | 0.47 | 0.89 (0.63 to 1.25) | 0.49 |
> 12 to ≤ 24 months | 72/82 | 0.84 (0.54 to 1.28) | 0.40 | 0.83 (0.53 to 1.31) | 0.43 |
> 24 months | 51/39 | 1.21 (0.72 to 2.03) | 0.48 | 1.20 (0.68 to 2.11) | 0.53 |
Per year | Â | 1.05 (0.91 to 1.21) | 0.51 | 1.02 (0.85 to 1.21) | 0.87 |