Table 1. Study Characteristics of genotypes in gastric cancer cases and controls in the analysis of XPD Lys751Gln polymorphism.
| First author | Year of publication | Quality assessment scores | Genotyping method | Total sample size | Number of controls | Number of cases | Study location | Ethnic group | P values for HWE | Controls, genotypes(n) Lys/Gln | All Cases, genotypes(n) Lys/Gln | ||||
| Lys/Lys | Lys/Gln | Gln/Gln | Lys/Lys | Lys/Gln | Gln/Gln | ||||||||||
| Huang WY | 2005 | 8.5 | MALDI-TOF/hME | 660 | 381 | 279 | Poland | Caucasian | 0.027863595 | 145 | 163 | 73 | 107 | 126 | 46 |
| Ye W# | 2006 | 8 | PCR–RFLP | 598 | 472 | 126 | Sweden | Caucasian | 0.114253032 | 198 | 203 | 71 | 49 | 61 | 16 |
| Lou Y | 2006 | 6 | PCR–RFLP | 438 | 200 | 238 | China | Asian | 0.377267735 | 164 | 33 | 3 | 205 | 30 | 3 |
| Ruzzo A* | 2007 | 7 | PCR–RFLP | 183 | 94 | 89 | Italy | Caucasian | 0.180617442 | 25 | 53 | 16 | 29 | 44 | 16 |
| Zhou RM# | 2007 | 7 | PCR–RFLP | 865 | 612 | 253 | China | Asian | 0.82380608 | 522 | 86 | 4 | 224 | 26 | 3 |
| Capella G# ∧ ¶ ★ | 2008 | 9 | Lightcycler | 1417 | 1172 | 245 | 10 European countries | Caucasian | 0.914544475 | 447 | 555 | 170 | 99 | 105 | 41 |
| Doecke J# | 2008 | 9 | Sequenom iPLEX | 1640 | 1337 | 303 | Australia | Caucasian | 0.220947678 | 575 | 588 | 174 | 127 | 140 | 36 |
| Zhang CZ | 2009 | 6.5 | PCR–RFLP | 419 | 212 | 207 | China | Asian | 0.439890159 | 172 | 39 | 1 | 166 | 39 | 2 |
| Canbay E | 2010 | 7 | PCR–RFLP | 287 | 247 | 40 | Turkey | Turkish population□ | 0.922153834 | 102 | 114 | 31 | 14 | 18 | 8 |
| Long XD∧ + | 2010 | 7.5 | TaqMan-PCR | 977 | 616 | 361 | China | Asian | 6.33741E-08 | 400 | 164 | 52 | 139 | 151 | 71 |
| Palli D | 2010 | 8 | TaqMan-PCR | 841 | 546 | 295 | Italy | Caucasian | 0.098569581 | 177 | 284 | 85 | 90 | 157 | 48 |
| Chen Z | 2011 | 6.5 | PCR–RFLP | 547 | 339 | 208 | China | Asian | 0.698246164 | 282 | 55 | 2 | 166 | 40 | 2 |
| Engin AB | 2011 | 4 | PCR–RFLP | 222 | 116 | 106 | Turkey | Turkish□ population | 0.005846887 | 40 | 43 | 33 | 30 | 56 | 20 |
Data of cardia type of gastric cancer were accessible;
Data of noncardia type of gastric cancer were accessible;
Data of sporadic diffuse-type of gastric cancer were accessible;
esophago-gastric junction adenocarcinoma (EGJAC) was treated as cardia type of gastric cancer in our meta-analysis.
Data of the status of Helicobacter pylori of gastric cancer were accessible.
Three kinds of controls (controls with severe chronic atrophic gastritis, controls without severe chronic atrophic gastritis, and total controls regardless of severe chronic atrophic gastritis) were presented in the study and total controls regardless of severe chronic atrophic gastritis were finally extracted into our database.
Here participants should be better considered as separate Turkish population conducted in our subgroup analysis due to their unknown ethnic backgrounds. RFLP: Restriction fragment length polymorphisms; TaqMan: TaqMan polymerase chain reaction method; MALDI-TOF/hME: SNPs were analyzed using Assisted Laser Desorption Ionization-Time of Flight mass spectrometry (MALDI-TOF MS) and homogeneous MassExtend (hME) chemistry (Sequenom Inc., San Diego, CA); Lightcycler: Polymorphisms were analysed in a LightCycler instrument by melting curve analysis of a fluorescently labelled sensor probe specific for each analysed variant, following manufacturer instructions (Roche Diagnostics, Mannheim, Germany), the results that were confirmed by a second genotyping method, such as restriction analysis, SSCP analysis or direct sequencing; Sequenom iPLEX : SNP typing was conducted using the Sequenom iPLEX protocol (Sequenom, San Diego, CA).