Table 6.
Odds ratios (OR) and 95% confidence intervals (CI) estimating the association between ESR1 rs9340799 and endometrial cancer by subgroups of other endometrial cancer risk factors
| ORs and CIs for rs9340799 genotypea | |||||
| Covariate | Case/contl | A/A | A/G | GG | P for interaction |
| Use of oral low potency estrogen (estriol) | |||||
| Never | 533/1213 | 1 (ref) | 0.79 (0.64–0.99) | 0.55 (0.37–0.81) | |
| Ever | 127/153 | 1.77 (1.20–2.61) | 1.28 (0.86–1.92) | 1.52 (0.74–3.15) | 0.50 |
| BMI (kg/m2) | |||||
| < 25 | 265/698 | 1 (ref) | 0.83 (0.61–1.13) | 0.62 (0.37–1.03) | |
| 25–28 | 136/387 | 1.01 (0.71–1.45) | 0.70 (0.48–1.02) | 0.59 (0.27–1.27) | |
| > 28 | 261/283 | 2.90 (2.05–4.11) | 2.05 (1.46–2.87) | 1.39 (0.80–2.43) | p = 0.93 |
| Smokingb | |||||
| Never | 434/783 | 1 (ref) | 0.84 (0.05–1.08) | 0.51 (0.33–0.80) | |
| Ever | 228/585 | 0.75 (0.56–1.00) | 0.50 (0.37–0.68) | 0.59 (0.35–0.98) | p = 0.17 |
| Use of combined oral contraceptives | |||||
| Never | 500/863 | 1 (ref) | 0.86 (0.68–1.09) | 0.58 (0.38–0.87) | |
| Ever | 162/505 | 0.63 (0.46–0.87) | 0.38 (0.27–0.54) | 0.43 (0.24–0.78) | p = 0.19 |
| Parity | |||||
| 0 childbirths | 94/137 | 1 (ref) | 0.78 (0.44–1.38) | 0.44 (0.16–1.24) | |
| 1 childbirth | 135/251 | 0.69 (0.41–1.18) | 0.62 (0.37–1.04) | 0.51 (0.23–1.11) | |
| ≥ 2 childbirths | 433/980 | 0.62 (0.39–0.96) | 0.45 (0.29–0.70) | 0.37 (0.21–0.65) | p = 0.88 |
| At at menopause (years) | |||||
| < 50 | 157/447 | 1 (ref) | 0.81 (0.53–1.20) | 0.51 (0.25–1.05) | |
| 50–51.5 | 125/393 | 0.98 (0.64–1.48) | 0.68 (0.45–1.04) | 0.79 (0.40–1.55) | |
| > 51.5 | 294/470 | 1.75 (1.23–2.51) | 1.48 (1.03–2.12) | 0.95 (0.54–1.66) | p = 0.72 |
| Age at last birth (years, among parous only) | |||||
| ≤ 27 | 209/364 | 1 (ref) | 0.66 (0.46–0.97) | 0.75 (0.40–1.41) | |
| 27.5–32.5 | 194/452 | 0.75 (0.52–1.09) | 0.53 (0.36–0.79) | 0.33 (0.17–0.64) | |
| ≥ 33 | 165/415 | 0.55 (0.37–0.81) | 0.52 (0.35–0.77) | 0.39 (0.20–0.75) | p = 0.46 |
| Family history of endometrial cancerc | |||||
| No | 564/1262 | 1 (ref) | 0.78 (0.63–0.97) | 0.63 (0.44–0.90) | |
| Yes | 65/67 | 2.56 (1.47–4.46) | 1.28 (0.76–2.18) | 1.48 (0.39–5.66) | p = 0.51 |
a Analyses were conditioned on age, hormone use for more than two years, and diabetes mellitus b Smoking is defined as having smoked at least 100 cigarettes or having smoked regularly for at least one year c Family history is defined as having a mother or a sister with endometrial cancer.