Association between MTHFR genotypes and colon cancer risk, stratified by hormone replacement therapy (postmenopausal women)a
| Recent hormone replacement therapy . | MTHFR 677 . | MTHFR 1298 . | . | . | . | . | . | . | . | . | . | . | . | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | . | AA . | . | . | . | AC . | . | . | . | CC . | . | . | . | |||||||||||
| . | . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | |||||||||||
| No | CC | 70 | 61 | 1.0 | — | 107 | 120 | 0.8 | (0.5–1.2) | 35 | 76 | 0.4 | (0.2–0.7) | |||||||||||
| CT | 115 | 127 | 0.8 | (0.5–1.2) | 92 | 100 | 0.8 | (0.5–1.3) | ||||||||||||||||
| TT | 46 | 64 | 0.6 | (0.4–1.1) | ||||||||||||||||||||
| Yes | CC | 10 | 31 | 0.3 | (0.1–0.6) | 41 | 61 | 0.6 | (0.3–1.0) | 12 | 23 | 0.5 | (0.2–1.1) | |||||||||||
| CT | 33 | 58 | 0.5 | (0.3–0.9) | 31 | 43 | 0.6 | (0.4–1.1) | ||||||||||||||||
| TT | 17 | 26 | 0.6 | (0.3–1.2) | ||||||||||||||||||||
| Recent hormone replacement therapy . | MTHFR 677 . | MTHFR 1298 . | . | . | . | . | . | . | . | . | . | . | . | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | . | AA . | . | . | . | AC . | . | . | . | CC . | . | . | . | |||||||||||
| . | . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | Cases (n) . | Ctrls (n) . | Odds ratio . | 95% confidence interval . | |||||||||||
| No | CC | 70 | 61 | 1.0 | — | 107 | 120 | 0.8 | (0.5–1.2) | 35 | 76 | 0.4 | (0.2–0.7) | |||||||||||
| CT | 115 | 127 | 0.8 | (0.5–1.2) | 92 | 100 | 0.8 | (0.5–1.3) | ||||||||||||||||
| TT | 46 | 64 | 0.6 | (0.4–1.1) | ||||||||||||||||||||
| Yes | CC | 10 | 31 | 0.3 | (0.1–0.6) | 41 | 61 | 0.6 | (0.3–1.0) | 12 | 23 | 0.5 | (0.2–1.1) | |||||||||||
| CT | 33 | 58 | 0.5 | (0.3–0.9) | 31 | 43 | 0.6 | (0.4–1.1) | ||||||||||||||||
| TT | 17 | 26 | 0.6 | (0.3–1.2) | ||||||||||||||||||||
Adjusted for age, body mass index, lifetime vigorous activity, energy intake, diet fiber, calcium, usual number of cigarettes smoked. Relative excess risk due to interaction P < 0.01. Wald χ2 test of slopes, A1298C/HRT use relationship P = 0.04. Wald χ2 test of slopes, C677T/HRT use relationship P = 0.09.