Table 1. Characteristics of included studies.
| Author | Year | Study type | Ethnicity (Country) | Cancer type | Source of control | Genotyping | Matching Y/N | Sample size Case/Control | Qualitya control | PHWE |
|---|---|---|---|---|---|---|---|---|---|---|
| Peng[15] | 2014 | Case-control | Asian (China) | ESCC | Population | Sequenom | N | 50/50 | N | NA |
| Peng[15] | 2014 | Case-control | Asian (China) | GCA | Population | Sequenom | N | 50/50 | N | NA |
| Piao [16] | 2014 | Case-control | Asian (Korea) | ESCC | Population | HRM | Y | 321/1700 | Y | 0.724 |
| Gu [17] | 2012 | Case-control | Asian (China) | ESCC | Hospital | MassArray | Y | 379/375 | Y | 0.648 |
| Wei [18] | 2012 | Case-control | Asian (China) | ESCC | Population | PCR-RFLP | Y | 240/198 | Y | 0.354 |
| Dura [19] | 2012 | Case-control | Caucasian (Netherland) | ESCC | Population | Real-Time PCR | Y | 344/580 | N | 0.267 |
| Zhou [20] | 2012 | Case-control | Asian (China) | ESCC | Population | Chips | Y | 4722/4732 | Y | 0.639 |
| Ren [21] | 2011 | Case-control | Asian (China) | GCA | Population | Chips | Y | 2748/10136 | Y | 0.407 |
| Shang [22] | 2011 | Case-control | Asian (China) | ESCC | Population | MALDI-TOF-MS | Y | 190/211 | N | 0.336 |
| Zhang [23] | 2011 | Case-control | Asian (China) | GCA | Population | TaqMan | Y | 1668/1841 | Y | 0.284 |
| Wang [10] | 2010 | GWAS | Asian (China) | ESCC | Population | Chips | Y | 9053/13283 | Y | NA |
| Wang [10] | 2010 | GWAS | Asian (China) | GCA | Population | Chips | Y | 2766/11013 | Y | NA |
ESCC, Esophageal squamous cell carcinoma; GCA, Gastric cardia adenocarcinoma; NA: Not applicable for the lack of C allele;
HRM, High-resolution melting; MALDI-TOF-MS, Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry;
aQuality control was conducted when sample of cases and controls was genotyped.