Table 3.
Effect of folate treatment on the risk of adenomas, by MTHFR genotype
| Genotype | Any Adenoma | Advanced Adenoma† | ||
|---|---|---|---|---|
| Ns § | Folate/Placebo RR* (95% CI) | Ns § | Folate/Placebo RR (95% CI) | |
| 677C>T (n) Folate/Placebo§ | Folate /Placebo§ | Folate/Placebo | ||
| CC (204/201) | 96/86 | 1.09 (0.87–1.36) | 21/22 | 0.96 (0.54–1.68) |
| CT (203/197) | 93/84 | 1.06 (0.85–1.33) | 22/15 | 1.48 (0.78–2.79) |
| TT (43/50) | 16/20 | 0.93 (0.57–1.53) | 4/4 | 1.30 (0.34–4.96) |
| C.1298A>C (n) | ||||
| AA (218/226) | 91/91 | 1.01 (0.81–1.26) | 22/21 | 1.11 (0.62–1.98) |
| AC (189/190) | 94/84 | 1.11 (0.89–1.39) | 21/17 | 1.22 (0.66–2.27) |
| CC (44/33) | 20/16 | 1.02 (0.62–1.68) | 6/3 | 1.40 (0.36–5.38) |
| MTHFR 677/1298 Genotype§ | ||||
| CC/AA (69/68) | 27/28 | 0.90 (0.60–1.35) | 4/10 | 0.39 (0.13–1.19) |
| CC/AC (92/100) | 49/42 | 1.25 (0.92–1.72) | 13/9 | 1.41 (0.62–3.22) |
| CC/CC (43/33) | 20/16 | 1.04 (0.63–1.72) | 6/3 | 1.44 (0.37–5.54) |
| CT/AA (106/108) | 48/43 | 1.12 (0.82–1.53) | 14/7 | 2.05 (0.85–4.95) |
| CT/AC (97/89) | 45/41 | 0.99 (0.72–1.37) | 8/8 | 0.99 (0.38–2.55) |
| TT/CC (43/50) | 16/20 | 0.93 (0.56–1.53) | 4/4 | 1.30 (0.34–4.95) |
*
RR = risk ratio for effect of 1 mg/day folate supplement versus placebo on adenoma recurrence risk; CI = confidence interval. RRs were adjusted for age, sex, clinical center, and aspirin treatment assignment.
§
Number of subjects in folate/placebo treatment groups.
†
Advanced adenoma defined as tubulovillous or villous adenoma, large adenoma (≥ 1 cm), carcinoma in situ, or invasive cancer.