Table 1. Main characteristics of all studies included in the meta-analysis.
| First author | Year | Country | Ethnicity | Cancer type | Sourceof controls | Genotyping method | Cases | Controls | Case | Control | G alleleincontrols(%) | HWE | ||||
| AA | AG | GG | AA | AG | GG | |||||||||||
| Hu | 2008 | China | Asian | Breast | PB | PCR-RFLP | 1009 | 1093 | 707 | 258 | 44 | 816 | 248 | 29 | 0.14 | 0.06 |
| Tian | 2009 | China | Asian | Lung | PB | PCR-RFLP | 1058 | 1035 | 781 | 253 | 24 | 755 | 254 | 26 | 0.15 | 0.40 |
| Catucci | 2010 | Italy | Caucasian | Breast | HB | Sequencing | 756 | 1242 | 414 | 295 | 47 | 704 | 452 | 86 | 0.25 | 0.25 |
| Catucci | 2010 | Germany | Caucasian | Breast | HB | Sequencing | 823 | 925 | 536 | 250 | 37 | 601 | 290 | 34 | 0.19 | 0.89 |
| Srivastava | 2010 | India | Caucasian | Gallbladder | PB | PCR-RFLP | 230 | 230 | 112 | 97 | 21 | 121 | 94 | 15 | 0.27 | 0.57 |
| Liu | 2010 | America | Caucasian | SCCHN | HB | PCR-RFLP | 1109 | 1130 | 745 | 309 | 55 | 710 | 366 | 54 | 0.21 | 0.44 |
| George | 2010 | India | Caucasian | Prostate | HB | PCR-RFLP | 159 | 230 | 48 | 98 | 13 | 104 | 92 | 34 | 0.35 | 0.07 |
| Okubo | 2010 | Japan | Asian | Gastric | HB | PCR-RFLP | 552 | 697 | 364 | 151 | 37 | 466 | 198 | 33 | 0.19 | 0.05 |
| Zhou | 2011 | China | Asian | CSCC | HB | PCR-RFLP | 226 | 309 | 134 | 84 | 8 | 223 | 71 | 15 | 0.16 | 0.00 |
| Mittal | 2011 | India | Caucasian | Bladder | HB | PCR-RFLP | 212 | 250 | 95 | 92 | 25 | 121 | 94 | 35 | 0.33 | 0.02 |
HB: hospital-based of control; PB: population-based of control; PCR-RFLP: polymerase chain reaction-restriction fragment length polymorphism; HWE: Hardy -Weinberg equilibrium; SCCHN: squamous cell carcinoma of the head and neck; CSCC: cervical squa-mous cell carcinoma.