Table 3. Meta-analysis of the MTHFR gene polymorphisms on HCC risk.
| Comparison | Population | No. of studies | Test of association | Mode | Test of heterogeneity | ||||
| OR | 95% CI | P Value | χ2 | PQ Value | I2 | ||||
| C677T | |||||||||
| TT vs. CC | Overall | 12 | 1.213 | 0.946–1.555 | 0.128 | R | 22.04 | 0.024 | 50.1 |
| Caucasian | 5 | 1.351 | 0.640–2.853 | 0.430 | R | 19.08 | 0.001 | 79.0 | |
| Asian | 7 | 1.192 | 0.988–1.439 | 0.067 | F | 2.82 | 0.831 | 0.0 | |
| PB | 6 | 1.211 | 0.777–1.889 | 0.398 | R | 13.87 | 0.016 | 64.0 | |
| HB | 6 | 1.190 | 0.956–1.482 | 0.119 | F | 8.12 | 0.150 | 38.4 | |
| CT vs. CC | Overall | 12 | 1.001 | 0.884–1.134 | 0.984 | F | 11.34 | 0.415 | 3.0 |
| Caucasian | 5 | 0.896 | 0.701–1.146 | 0.383 | F | 2.48 | 0.649 | 0.0 | |
| Asian | 7 | 1.040 | 0.900–1.202 | 0.593 | F | 7.85 | 0.250 | 23.5 | |
| PB | 6 | 1.081 | 0.902–1.295 | 0.399 | F | 7.65 | 0.177 | 34.6 | |
| HB | 6 | 0.934 | 0.787–1.109 | 0.436 | F | 2.43 | 0.787 | 0.0 | |
| TT vs. CT+CC | Overall | 12 | 1.194 | 0.979–1.457 | 0.080 | R | 19.01 | 0.061 | 42.1 |
| Caucasian | 5 | 1.406 | 0.740–2.672 | 0.298 | R | 16.88 | 0.002 | 76.3 | |
| Asian | 7 | 1.151 | 0.987–1.343 | 0.073 | F | 1.20 | 0.977 | 0.0 | |
| PB | 6 | 1.133 | 0.792–1.621 | 0.493 | R | 11.58 | 0.041 | 56.8 | |
| HB | 6 | 1.252 | 0.981–1.598 | 0.070 | F | 7.16 | 0.209 | 30.2 | |
| TT+CT vs. CC | Overall | 12 | 1.058 | 0.905–1.237 | 0.481 | R | 18.16 | 0.078 | 39.4 |
| Caucasian | 5 | 1.048 | 0.712–1.542 | 0.812 | R | 10.47 | 0.033 | 61.8 | |
| Asian | 7 | 1.072 | 0.935–1.228 | 0.319 | F | 7.34 | 0.290 | 18.3 | |
| PB | 6 | 1.111 | 0.837–1.475 | 0.467 | R | 12.54 | 0.028 | 60.1 | |
| HB | 6 | 1.004 | 0.856–1.179 | 0.960 | F | 5.01 | 0.415 | 0.2 | |
| A1298C | |||||||||
| CC vs. AA | Overall | 6 | 0.660 | 0.460–0.946 | 0.024 | F | 7.19 | 0.207 | 30.5 |
| Caucasian | 1 | 0.720 | 0.309–1.677 | 0.446 | – | – | – | – | |
| Asian | 5 | 0.647 | 0.435–0.963 | 0.032 | F | 7.20 | 0.126 | 44.4 | |
| PB | 4 | 0.519 | 0.327–0.823 | 0.005 | F | 3.78 | 0.286 | 20.7 | |
| HB | 2 | 1.045 | 0.567–1.927 | 0.888 | F | 0.62 | 0.432 | 0.0 | |
| AC vs. AA | Overall | 6 | 1.055 | 0.900–1.236 | 0.510 | F | 3.44 | 0.633 | 0.0 |
| Caucasian | 1 | 0.828 | 0.513–1.336 | 0.440 | – | – | – | – | |
| Asian | 5 | 1.087 | 0.919–1.286 | 0.331 | F | 2.33 | 0.676 | 0.0 | |
| PB | 4 | 1.033 | 0.860–1.241 | 0.725 | F | 1.15 | 0.756 | 0.0 | |
| HB | 2 | 1.121 | 0.817–1.538 | 0.480 | F | 2.08 | 0.149 | 32.1 | |
| CC vs. AC+AA | Overall | 6 | 0.667 | 0.470–0.948 | 0.024 | F | 8.13 | 0.149 | 38.5 |
| Caucasian | 1 | 0.780 | 0.343–1.774 | 0.554 | – | – | – | – | |
| Asian | 5 | 0.627 | 0.330–1.192 | 0.154 | R | 8.07 | 0.089 | 50.4 | |
| PB | 4 | 0.522 | 0.332–0.821 | 0.005 | F | 4.34 | 0.227 | 30.8 | |
| HB | 2 | 1.054 | 0.583–1.903 | 0.863 | F | 0.82 | 0.365 | 0.0 | |
| CC+AC vs. AA | Overall | 6 | 0.995 | 0.855–1.159 | 0.953 | F | 2.73 | 0.742 | 0.0 |
| Caucasian | 1 | 0.808 | 0.513–1.270 | 0.355 | – | – | – | – | |
| Asian | 5 | 1.023 | 0.870–1.202 | 0.788 | F | 1.80 | 0.772 | 0.0 | |
| PB | 4 | 0.958 | 0.803–1.143 | 0.634 | F | 0.67 | 0.881 | 0.0 | |
| HB | 2 | 1.113 | 0.823–1.506 | 0.485 | F | 1.33 | 0.249 | 24.8 | |
OR, odds ratio; CI, confidence intervals; R, random effects model; F, fixed effects model; PB, Population–based; HB, Hospital–based.