Table I.
Main characteristics of studies included in the meta-analysis.
| Author, year | Population (countrol of origin) | Characteristics of control (matched for) | Source of control | Genotyping method | Sample size (case/control) | Genotype distribution (TT/GT/GG) | HWE | Refs. | |
|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||
| Case | Control | ||||||||
| Er et al, 2012 | Chinese (Hebei, China) | Healthy (age, gender) | HCC | PCR-RFLP | 158/142 | 34/74/50 | 41/78/23 | Yes | (19) |
| Zhang et al, 2011 | Chinese (Nanjing, China) | Healthy (age, gender, sample size) | PCC | PCR-RFLP | 574/574 | 173/260/141 | 179/316/79 | Yes | (13) |
| Er et al, 2009 | Chinese (Hebei, China) | Healthy (age, gender) | HCC | PCR-RFLP | 106/106 | 23/51/32 | 39/46/21 | No | (20) |
| Cho et al, 2008 | Korean (Seoul, Korea) | Healthy | PCC | PCR-RFLP | 239/299 | 64/110/65 | 61/152/86 | Yes | (15) |
| Yang et al, 2007 | Chinese (Beijing, China) | Healthy (age, gender) | PCC | PCR-RFLP | 500/1000 | 107/250/143 | 298/498/204 | DNRa | (22) |
| Cao et al, 2007 | Chinese (Hebei, China) | Healthy | PCC | PIRA-PCR | 212/642 | 21/91/100 | 117/299/226 | Yes | (21) |
| Ohmiya et al, 2006 | Japanese (Nagoya, Japan) | Subjects without gastric tumors (ethnicity, gender) | HCC | PCR-RFLP | 410/438 | 98/188/124 | 99/241/98 | Yes | (23) |
a
?; HWE, Hardy-Weinberg equilibrium; HCC, hospital-based case-control; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; PCC, population-based case-control; DNR, data not reported; PIRA, primer-introduced restriction analysis.