| Cases (n = 318) | Controls (n = 647) | P value †|
---|---|---|---|
Demographics | Â | Â | Â |
   Age, years (mean ± SD) | 64.4 ± 6.88 | 64.2 ± 6.86 | 0.67 |
   White,% | 95.0 | 95.1 | 0.95 |
Family history/breast-related procedures | Â | Â | Â |
   Mother or sister with breast cancer,% | 18.6 | 15.6 | 0.25 |
   Mammography in past 2 years,% | 93.1 | 93.7 | 0.73 |
   Prior breast biopsy,% | 28.0 | 21.8 | 0.03 |
Reproductive factors | Â | Â | Â |
   Early age at menarche,% <12 years | 20.1 | 18.1 | 0.44 |
   Nulliparous, % | 12.9 | 9.74 | 0.14 |
   Age at first birth, years (mean ± SD) ‡ | 24.1 ± 4.85 | 23.3 ± 4.39 | 0.05 |
   Parity, number of births (mean ± SD) ‡ | 2.60 ± 1.09 | 2.86 ± 1.21 | <0.01 |
   Age at menopause, years (mean ± SD) | 47.9 ± 5.37 | 47.4 ± 5.84 | 0.37 |
Ever use of estrogen plus progestin postmenopausal hormones, % | 48.1 | 35.2 | <0.01 |
Lifestyle/anthropomorphic factors | Â | Â | Â |
   Height, in (mean ± SD) | 64.9 ± 2.65 | 64.8 ± 2.61 | 0.36 |
   Baseline BMI, kg/m2 (mean ± SD) | 26.9 ± 5.63 | 27.2 ± 5.61 | 0.21 |
   Total physical activity, MET-hour/week (mean ± SD) | 9.44 ± 11.9 | 10.1 ± 13.9 | 0.90 |
Dietary factors | Â | Â | Â |
   Total folate, DFE/day (mean ± SD) § | 819 ± 420 | 856 ± 419 | 0.15 |
   Dietary methionine, g/day (mean ± SD) | 1.43 ± 0.57 | 1.48 ± 0.61 | 0.32 |
   Total B2, mg/day (mean ± SD) § | 2.53 ± 1.21 | 2.64 ± 1.28 | 0.16 |
   Total B6, mg/day (mean ± SD) § | 10.1 ± 30.3 | 7.97 ± 15.4 | 0.38 |
   Total B12, μg/day (mean ± SD) § | 22.5 ± 40.2 | 18.9 ± 29.3 | 0.57 |
   Alcohol, g/day (mean ± SD) | 5.96 ± 8.91 | 4.76 ± 9.76 | 0.03 |
Multivitamin use, days/week over 10 years (mean ± SD) | 3.29 ± 2.90 | 3.50 ± 2.93 | 0.25 |