Table 3

Joint association of MTHFR genotype and folate intake with breast cancer risk among Chinese women, Shanghai Breast Cancer Study, 1996–1998

GenotypeDaily Folate IntakeaP for trend
Q4 (High)Q3Q2Q1
Cases/ controlsAdjusted OR (95% CI)aCases/ controlsAdjusted OR (95% CI)aCases/ controlsAdjusted OR (95% CI)aCases/ controlsAdjusted OR (95% CI)a
C677T b
CC69/881.00 (reference)96/861.76 (1.12–2.77)90/911.75 (1.08–2.83)81/861.94 (1.15–3.26)0.02
CT103/1171.16 (0.76–1.77)135/1421.50 (0.99–2.29)133/1371.73 (1.11–2.70)145/1362.17 (1.34–3.51)0.06
TT29/530.70 (0.40–1.23)47/441.66 (0.97–2.85)49/392.17 (1.23–3.81)47/382.51 (1.37–4.60)0.003
P for trend0.510.710.490.31
A1298C c
AA140/1921.00 (reference)184/1921.59 (1.15–2.20)195/1851.94 (1.36–2.76)194/1862.18 (1.46–3.25)0.0006
AC/CC63/811.05 (0.70–1.57)92/841.80 (1.22–2.67)79/911.59 (1.04–2.44)85/921.94 (1.23–3.05)0.18
A1298C-AA d
C677T-CC42/451.00 (reference)43/431.26 (0.68–2.34)48/381.81 (0.95–3.44)43/401.85 (0.94–3.67)0.07
C677T-CT67/810.86 (0.49–1.48)94/1011.18 (0.69–2.01)90/981.35 (0.77–2.36)100/981.74 (0.96–3.16)0.08
C677T-TT29/520.56 (0.30–1.05)45/411.40 (0.75–2.60)48/361.87 (0.98–3.57)46/362.16 (1.09–4.28)0.002
P for trend0.130.630.810.70
  • a All ORs are adjusted for age, waist-to-hip ratio, age at first live birth, physical activity, and total energy, meat, vitamin B12, vitamin B6, and methionine intakes. OR, odds ratio; CI, confidence interval.

  • b P for interaction, 0.048.

  • c P for interaction, 0.71.

  • d P for interaction, 0.06.