Table V.
Adjusted odds ratios for polymorphisms in folate-related genes and colorectal cancer, stratified by plasma folate concentrationsa.
| Plasma folate quintiles, ng/ml | |||||
| Genotypes | >11 | >7.72 to ≤11 | >5.76 to ≤7.72 | >4.12 to ≤5.76 | ≤4.12 |
| N | 170 | 170 | 172 | 170 | 172 |
| Total | 1.00 (reference) | 1.10 (0.69–1.73) | 1.34 (0.85–2.11) | 1.54 (0.98–2.42) | 3.34 (2.06–5.43) |
| MTHFR 677C>T | |||||
| CC | 1.00 (reference) | 0.62 (0.29–1.32) | 1.09 (0.50–2.35) | 1.12 (0.51–2.47) | 3.23 (1.24–8.39) |
| CT+TT | 1.00 (reference) | 1.53 (0.85–2.78) | 1.48 (0.83–2.62) | 1.85 (1.06–3.25) | 3.68 (2.04–6.63) |
| MTHFR 1298A>C | |||||
| AA | 1.00 (reference) | 1.25 (0.72–2.18) | 1.31 (0.76–2.25) | 1.38 (0.81–2.38) | 2.69 (1.52–4.77) |
| AC+CC | 1.00 (reference) | 0.67 (0.28–1.62) | 1.41 (0.61–3.28) | 1.85 (0.77–4.44) | 6.10 (2.27–16.44) |
| TSER 2R/3R | |||||
| 3R3R | 1.00 (reference) | 1.19 (0.68–2.09) | 1.11 (0.63–1.95) | 1.62 (0.93–2.83) | 3.09 (1.72–5.55) |
| 2R3R+2R2R | 1.00 (reference) | 0.96 (0.43–2.16) | 1.96 (0.90–4.27) | 1.38 (0.62–3.04) | 3.99 (1.63–9.74) |
| TS 1494 0bp/6bp | |||||
| 0bp0bp | 1.00 (reference) | 1.32 (0.66–2.65) | 1.40 (0.72–2.69) | 1.35 (0.72–2.54) | 3.57 (1.71–7.47) |
| 0bp6bp+6bp6bp | 1.00 (reference) | 1.01 (0.54–1.90) | 1.33 (0.70–2.51) | 1.65 (0.85–3.21) | 3.45 (1.77–6.73) |
| MTHFR 677/1298 | |||||
| CC/AA | 1.00 (reference) | 0.50 (0.16–1.55) | 0.47 (0.13–1.66) | 0.35 (0.09–1.27) | 2.59 (0.51–13.12) |
| CC/AC+CC | 1.00 (reference) | 0.59 (0.19–1.87) | 1.90 (0.61–5.90) | 2.69 (0.85–8.56) | 4.79 (1.34–17.13) |
| CT+TT/AA | 1.00 (reference) | 1.70 (0.87–3.33) | 1.56 (0.82–2.98) | 1.95 (1.04–3.64) | 3.13 (1.64–5.98) |
| CT/AC | 1.00 (reference) | 0.92 (0.22–3.92) | 1.08 (0.27–4.34) | 1.14 (0.27–4.82) | 8.99 (1.76–45.93) |
| MTHFR 677/TSER | |||||
| CC/3R3R | 1.00 (reference) | 0.88 (0.35–2.18) | 0.65 (0.24–1.78) | 1.91 (0.70–5.19) | 2.19 (0.73–6.62) |
| CC/2R3R+2R2R | 1.00 (reference) | 0.22 (0.03–1.66) | 2.50 (0.60–10.49) | 0.40 (0.09–1.81) | 10.35 (0.83–129.72) |
| CT+TT/3R3R | 1.00 (reference) | 1.49 (0.71–3.12) | 1.34 (0.66–2.74) | 1.60 (0.81–3.20) | 3.66 (1.78–7.50) |
| CT+TT/2R3R+2R2R | 1.00 (reference) | 1.67 (0.59–4.70) | 1.83 (0.67–4.99) | 2.71 (0.97–7.61) | 4.96 (1.51–16.28) |
| MTHFR 1298/TSER | |||||
| AA/3R3R | 1.00 (reference) | 1.64 (0.82–3.27) | 1.24 (0.62–2.49) | 1.48 (0.75–2.89) | 2.86 (1.42–5.73) |
| AA/2R3R+2R2R | 1.00 (reference) | 0.82 (0.30–2.25) | 1.60 (0.64–3.97) | 1.19 (0.47–3.04) | 2.54 (0.87–7.39) |
| AC+CC/3R3R | 1.00 (reference) | 0.55 (0.18–1.67) | 1.02 (0.36–2.84) | 2.03 (0.70–5.86) | 4.48 (1.37–14.70) |
| AC+CC/2R3R | 1.00 (reference) | 0.89 (0.17–4.65) | 6.97 (0.89–54.71) | 1.57 (0.28–8.86) | 10.80 (1.39–83.76) |
| MTHFR 1298/TS 1494 | |||||
| AA/0bp0bp | 1.00 (reference) | 1.47 (0.65–3.33) | 1.35 (0.62–2.95) | 1.35 (0.63–2.88) | 3.47 (1.44–8.34) |
| AA/0bp6bp+6bp6bp | 1.00 (reference) | 1.13 (0.52–2.46) | 1.30 (0.59–2.87) | 1.32 (0.60–2.93) | 2.23 (0.99–5.04) |
| AC+CC/0bp0bp | 1.00 (reference) | 0.81 (0.17–3.91) | 1.30 (0.36–4.68) | 1.52 (0.44–5.28) | 4.24 (0.93–19.38) |
| AC+CC/0bp6bp+6bp6bp | 1.00 (reference) | 0.69 (0.21–2.25) | 1.45 (0.45–4.62) | 2.48 (0.61–10.04) | 8.85 (2.23–35.16) |
| TSER/TS 1494 | |||||
| 3R3R/0bp0bp | 1.00 (reference) | 1.79 (0.79–4.07) | 1.43 (0.66–3.07) | 1.76 (0.85–3.65) | 4.07 (1.75–9.47) |
| 3R3R/0bp6bp+6bp6bp | 1.00 (reference) | 0.99 (0.42–2.38) | 0.82 (0.34–1.98) | 1.22 (0.47–3.18) | 2.70 (1.07–6.79) |
| 2R3R+2R2R/0bp0bp | 1.00 (reference) | 0.63 (0.11–3.69) | 2.79 (0.53–14.67) | 0.42 (0.08–2.11) | 2.79 (0.40–19.67) |
| 2R3R+2R2R/0bp6bp+6bp6bp | 1.00 (reference) | 1.15 (0.44–3.04) | 2.38 (0.90–6.29) | 2.39 (0.88–6.47) | 4.77 (1.64–13.86) |
a
Models adjusted for age, gender, hypertension, diabetes mellitus and plasma folate concentrations. Results for genetic combinations associated with ORs lower than that found for the total sample in the lowest quintile (folate ≤4.12 ng/ml) are not shown. MTHFR, methylenetetrahydrofolate reductase; TS, thymidylate synthase; TSER, TS enhancer region; ORs, odds ratios.