Table 2.
Summary of the meta-analysis results.
| Polymorphism | Genetic model | Cancer type | N | OR (95%CI) | POR | Effect model | I2 (%) | PHeter | PBegg | PEgger |
|---|---|---|---|---|---|---|---|---|---|---|
| MTHFR C677T | C vs. T | All | 7 | 1.178 (0.855–1.624) | 0.317 | R | 53.6 | 0.044 | 0.230 | 0.562 |
| Rectal cancer | 6 | 1.223 (0.860–1.738) | 0.263 | R | 58.7 | 0.033 | ||||
| Esophageal cancer | 1 | |||||||||
| TRG 1–2 vs. 3–5 | 6 | 1.097 (0.779–1.544) | 0.596 | R | 53.9 | 0.055 | ||||
| TRG 1 vs. 2–5 | 2 | 1.590 (0.967–2.614) | 0.068 | R | 45.9 | 0.074 | ||||
| CC vs. TT | All | 7 | 1.185 (0.603–2.328) | 0.623 | R | 51.2 | 0.056 | 0.548 | 0.835 | |
| Rectal cancer | 6 | 1.274 (0.576–2.817) | 0.550 | R | 57.8 | 0.037 | ||||
| Esophageal cancer | 1 | |||||||||
| TRG 1–2 vs. 3–5 | 6 | 1.063 (0.558–2.027) | 0.852 | R | 48.2 | 0.086 | ||||
| TRG 1 vs. 2–5 | 2 | 2.221 (0.084–58.420) | 0.632 | R | 76.0 | 0.041 | ||||
| CT vs. TT | All | 6 | 0.727 (0.378–1.401) | 0.341 | R | 44.2 | 0.096 | 0.548 | 0.746 | |
| Rectal cancer | 5 | 0.776 (0.369–1.633) | 0.504 | R | 52.0 | 0.064 | ||||
| Esophageal cancer | 1 | |||||||||
| TRG 1–2 vs. 3–5 | 6 | 0.689 (0.443–1.074) | 0.100 | F | 31.9 | 0.197 | ||||
| TRG 1 vs. 2–5 | 2 | 1.233 (0.015–98.183) | 0.925 | R | 85.5 | 0.009 | ||||
| CC vs. CTTT | All | 7 | 1.426 (1.074–1.894) | 0.014 | F | 18.6 | 0.283 | 0.386 | 0.363 | |
| Rectal cancer | 6 | 1.483 (1.102–1.996) | 0.009 | F | 35.6 | 0.170 | ||||
| Esophageal cancer | 2 | 0.953 (0.365–2.492) | 0.922 | F | 0.0 | 0.770 | ||||
| TRG 1–2 vs. 3–5 | 6 | 1.423 (1.046–1.936) | 0.025 | F | 37.8 | 0.154 | ||||
| TRG 1 vs. 2–5 | 3 | 1.619 (0.899–2.915) | 0.108 | F | 0.0 | 0.664 | ||||
| Rectal cancer | 2 | 1.766 (0.947–3.291) | 0.074 | F | 0.0 | 0.750 | ||||
| CCCT vs. TT | All | 7 | 0.913 (0.501–1.664) | 0.767 | R | 46.8 | 0.080 | 0.764 | 0.742 | |
| Rectal cancer | 6 | 0.968 (0.476–1.970) | 0.929 | R | 54.4 | 0.052 | ||||
| Esophageal cancer | 1 | |||||||||
| TRG 1–2 vs. 3–5 | 6 | 0.863 (0.580–1.283) | 0.466 | F | 39.1 | 0.145 | ||||
| TRG 1 vs. 2–5 | 2 | 1.773 (0.041–76.720) | 0.766 | R | 82.2 | 0.018 | ||||
| MTHFR A1298C | A vs. C | Rectal cancer | 5 | 0.978 (0.771–1.241) | 0.857 | F | 21.0 | 0.281 | 0.806 | 0.976 |
| AA vs. CC | Rectal cancer | 5 | 1.169 (0.683–2.002) | 0.569 | F | 37.7 | 0.170 | 0.462 | 0.550 | |
| AC vs. CC | Rectal cancer | 5 | 1.418 (0.824–2.439) | 0.207 | F | 34.2 | 0.194 | 0.221 | 0.504 | |
| AA vs. ACCC | Rectal cancer | 5 | 0.875 (0.639–1.199) | 0.406 | F | 0.0 | 0.458 | 0.806 | 0.912 | |
| AAAC vs. CC | Rectal cancer | 5 | 1.285 (0.768–2.148) | 0.340 | F | 36.4 | 0.179 | 0.462 | 0.492 | |
| EGFR G497A | G vs. A | All | 2 | 0.812 (0.561–1.176) | 0.271 | F | 25.1 | 0.248 | ||
| GG vs. AA | All | 2 | 1.244 (0.519–2.982) | 0.624 | F | 5.9 | 0.303 | |||
| GA vs. AA | All | 2 | 0.994 (0.398–2.486) | 0.990 | F | 0.0 | 0.610 | |||
| GG vs. GAAA | All | 3 | 0.930 (0.431–2.007) | 0.853 | R | 60.9 | 0.078 | 1.000 | 0.423 | |
| TRG 1–2 vs. 3–5 | 2 | 1.267 (0.762–2.106) | 0.362 | F | 15.6 | 0.276 | ||||
| TRG 1 vs. 2–5 | 2 | 0.913 (0.472–1.765) | 0.362 | R | 76.3 | 0.040 | ||||
| GGGA vs. AA | All | 2 | 1.139 (0.488–2.662) | 0.763 | F | 0.0 | 0.384 | |||
| EGFR CA repeat | S vs. L | All | 4 | 0.639 (0.397–1.030) | 0.066 | F | 38.3 | 0.182 | 1.000 | 0.938 |
| Rectal Cancer | 3 | 0.708 (0.299–1.677) | 0.433 | R | 54.8 | 0.109 |