Table 4.
Characteristics of populations and cancer types of the individual studies included in the meta-analysis
| Study | Year | Ethnicity | Country | Sample size (case/control) | Histologic subtype | Genotype method | Case | Control | Case | Control | HWE | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
|
|
|
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| GG | GA | AA | GG | GA | AA | G | A | G | A | ||||||||
| Cheng et al. | 2011 | Asians | China | 205/205 | ESCC | PCR-RFLP | 54 | 105 | 46 | 90 | 79 | 36 | 213 | 197 | 259 | 151 | no |
| Cai et al. | 2011 | Asians | China | 125/250 | ESCC | PCR-RFLP | 30 | 68 | 27 | 70 | 133 | 47 | 128 | 122 | 273 | 227 | Yes |
| Sun et al. | 2008 | Asians | China | 1010/1008 | ESCC | PCR-RFLP | 448 | 434 | 128 | 529 | 406 | 73 | 1330 | 690 | 1464 | 552 | Yes |
| Our study | 2013 | Asians | China | 629/686 | ESCC | PCR-LDR | 307 | 254 | 43 | 310 | 296 | 58 | 868 | 340 | 916 | 412 | Yes |
ESCC, esophageal squamous cell carcinoma. PCR-RFLP, polymerase chain reaction-restriction fragment length polymorphism. PCR-LDR, polymerase chain reaction-ligase detection reaction. HWE, Hardy-Weinberg equilibrium.