Table 2.
Association between early life exposures and promoter methylation of E-cadherin, p16, and RAR-β2 genes in breast tumors among premenopausal women: case-case comparisons
| E-cadherin | p16 | RAR-β2 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| M | UM | OR (95% CI) 1 | M | UM | OR (95% CI) 1 | M | UM | OR (95% CI) 1 | |
| Birth weight (kg) | |||||||||
| ≤2.5 | 10 | 18 | 2.79 (1.15–6.82) | 6 | 22 | 0.70 (0.27–1.85) | 7 | 21 | 1.00 (0.39–2.57) |
| 2.6–3.9 | 28 | 135 | 1.0 | 45 | 118 | 1.0 | 42 | 121 | 1.0 |
| >3.9 | 9 | 26 | 1.69 (0.70–4.05) | 8 | 27 | 0.79 (0.33–1.88) | 12 | 23 | 1.61 (0.72–3.60) |
| Birth order | |||||||||
| First born | 14 | 49 | 1.0 | 20 | 43 | 1.0 | 23 | 40 | 1.0 |
| Other than first born | 35 | 134 | 0.83 (0.40–1.69) | 40 | 129 | 0.68 (0.35–1.30) | 40 | 129 | 0.52 (0.27–1.02) |
| Maternal age at delivery (yrs) | |||||||||
| <25 | 15 | 70 | 1.0 | 27 | 58 | 1.0 | 22 | 63 | 1.0 |
| 25–30 | 18 | 53 | 1.85 (0.81–4.20) | 12 | 59 | 0.41 (0.18–0.90) | 18 | 53 | 0.76 (0.35–1.63) |
| >30 | 13 | 54 | 1.25 (0.54–2.89) | 19 | 48 | 0.82 (0.41–1.67) | 20 | 47 | 1.21 (0.58–2.49) |
| Having been breastfed | |||||||||
| Yes | 9 | 43 | 1.0 | 9 | 43 | 1.0 | 12 | 40 | 1.0 |
| No | 34 | 119 | 1.21 (0.50–2.93) | 45 | 108 | 2.75 (1.14–6.62) | 47 | 106 | 1.18 (0.53–2.62) |
| Age at menarche (yrs) | |||||||||
| <12 | 11 | 48 | 0.81 (0.37–1.81) | 18 | 41 | 1.66 (0.81–3.38) | 15 | 44 | 0.83 (0.40–1.75) |
| 12–13 | 27 | 95 | 1.0 | 27 | 95 | 1.0 | 32 | 90 | 1.0 |
| >13 | 12 | 44 | 0.97 (0.44–2.14) | 16 | 40 | 1.42 (0.68–2.96) | 17 | 39 | 1.28 (0.62–2.64) |
| Age at first live birth (yrs) | |||||||||
| <23 | 18 | 51 | 1.0 | 16 | 53 | 1.0 | 20 | 49 | 1.0 |
| 23–29 | 20 | 70 | 0.92 (0.42–2.00) | 23 | 67 | 0.81 (0.41–1.61) | 23 | 67 | 0.63 (0.30–1.33) |
| ≥30 | 5 | 34 | 0.48 (0.15–1.50) | 11 | 28 | 1.28 (0.61–2.66) | 11 | 28 | 0.80 (0.31–2.04) |
| Adult height (m) | |||||||||
| <1.60 | 10 | 40 | 1.02 | 11 | 39 | 1.02 | 7 | 43 | 1.02 |
| 1.60–1.64 | 16 | 62 | 0.94 (0.37–2.37) | 19 | 59 | 1.11 (0.46–2.68) | 23 | 55 | 3.00 (1.13–7.97) |
| ≥1.65 | 24 | 85 | 1.04 (0.40–2.74) | 31 | 78 | 1.39 (0.56–3.46) | 34 | 75 | 3.34 (1.19–9.39) |
| Weight at 20 years (kg) | |||||||||
| <54.4 | 22 | 79 | 1.0 | 23 | 78 | 1.0 | 27 | 74 | 1.0 |
| ≥54.4 | 28 | 108 | 0.97 (0.51–1.85) | 38 | 98 | 1.29 (0.71–2.37) | 37 | 99 | 1.08 (0.59–1.96) |
M – methylated; UM – un-methylated
1
Odds ratios and 95% confidence intervals adjusted for age, race, education, and ER status.
2
Odds ratios and 95% confidence intervals adjusted for age, race, education, ER status, weight at 20s, weight 2 years ago, and maternal height.