Table 1.
Characteristics of published studies included in this meta-analysis.
| First author | Country | Ethnicity | Cancer type | Sample size | Control source | Casea | Controla | Methods | HWE |
|---|---|---|---|---|---|---|---|---|---|
| de Oliveira 2015 | Brazilian | Caucasian | Gastric cancer | 262/240 | HB | 157/95/10 | 157/64/19 | PCR-RFLP | <0.01 |
| Yang 2009 | Korean | Asian | Gastric cancer | 84/325 | PB | 49/33/2 | 227/92/6 | PCR | 0.34 |
| Hou 2007 | Poland | Caucasian | Gastric cancer | 304/416 | PB | 226/74/4 | 312/99/5 | TaqMan | 0.36 |
| Sugimoto 2007 | Japanese | Asian | Gastric cancer | 105/172 | HB | 66/27/12 | 125/40/7 | PCR-RFLP | 0.11 |
| Shirai 2006 | Japanese | Asian | Gastric cancer | 168/479 | PB | 102/62/4 | 316/146/17 | TaqMan | 0.98 |
| Zambon 2005 | Italian | Caucasian | Gastric cancer | 129/644 | HB | 83/44/2 | 404/227/13 | PCR-RFLP | <0.01 |
| Wu 2004 | Chinese | Asian | Gastric cancer | 204/210 | PB | 148/51/5 | 152/56/2 | PCR | 0.20 |
| Ohyama 2004 | Japanese | Asian | Gastric cancer | 300/472 | HB | 193/98/9 | 312/144/16 | TaqMan | 0.90 |
| Lee 2004 | Korean | Asian | Gastric cancer | 341/261 | PB | 229/97/15 | 185/69/7 | PCR | 0.85 |
| Hamadien 2016 | Arabian | African | Colorectal cancer | 100/100 | HB | 85/15/0 | 85/15/0 | TaqMan | 0.42 |
| Kapitanović 2014 | Croatian | African | Colorectal cancer | 200/200 | PB | 130/64/6 | 126/67/7 | TaqMan | 0.60 |
| Garrity-Park 2008 | American | Caucasian | Colorectal cancer | 114/114 | HB | 98/16/0 | 92/22/0 | PCR | 0.25 |
| Landi 2006 | Spanish | Caucasian | Colorectal cancer | 281/268 | HB | 219/58/4 | 220/45/3 | TaqMan | 0.68 |
| Yang 2015 | Chinese | Asian | HCC | 298/889 | HB | 203/79/16 | 622/228/39 | PCR-RFLP | <0.01 |
| Shin 2015 | Korean | Asian | HCC | 157/201 | PB | 116/35/6 | 142/53/6 | PCR–RFLP | 0.70 |
| Jung 2009 | Korean | Asian | HCC | 227/ 365 | HB | 137/75/15 | 258/100/7 | PCR | 0.45 |
| Wang 2003 | Japanese | Asian | HCC | 125/55 | PB | 80/44/1 | 35/19/1 | PCR | 0.38 |
| Kohaar 2014 | Indian | Caucasian | Cervical cancer | 150/200 | HB | 99/44/7 | 102/85/13 | PCR-RFLP | 0.40 |
| Nieves-Ramirez 2011 | Mexican | Caucasian | Cervical cancer | 191/205 | PB | 93/82/16 | 114/76/15 | PCR | 0.64 |
| Deshpande 2005 | Hispanic | Caucasian | Cervical cancer | 139/115 | HB | 116/22/1 | 84/26/5 | PCR | 0.12 |
| Kesarwani 2009 | Indian | Caucasian | Prostate cancer | 197/256 | PB | 136/57/4 | 196/56/4 | PCR | 1.00 |
| Danforth 2008 | Hispanic | Caucasian | Prostate cancer | 1139/1378 | HB | 923/203/13 | 1110/254/14 | TaqMan | 0.90 |
a(A/B/C): A, B, and C represented the number of genotypes CC, TC, and TT, respectively; HCC, hepatocellular cancer; HWE, P value for Hardy-Weinberg equilibrium for TNF-α T-857C polymorphism among controls; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; TaqMan, a fluorogenic exonuclease assay.