Table 1. Characteristics of 42 included studies in this meta-analysis.
| Author | Year | Country | Ethnicity | Cases/Control | Sample size | Control source | Cancer type | Genotyping method | Quality score |
|---|---|---|---|---|---|---|---|---|---|
| Lin | 2006 | China | Asian | 212/201 | 413 | HB | OSCC | PCR-PAGE | 6 |
| Riemann | 2006 | Germany | Caucasian | 139/307 | 446 | HB | CRC | pyrosequencing | 7 |
| Riemann | 2006 | Germany | Caucasian | 72/307 | 379 | HB | BCCLL | pyrosequencing | 7 |
| Riemann | 2006 | Germany | Caucasian | 140/307 | 447 | HB | RCC | pyrosequencing | 7 |
| Riemann | 2007 | Germany | Caucasian | 242/307 | 549 | HB | BC | pyrosequencing | 7 |
| Lehnerdt | 2008 | Germany | Caucasian | 364/307 | 671 | HB | HNSCC | PCR-RFLP | 7 |
| Lo | 2009 | China | Asian | 182/116 | 298 | HB | GC | PCR-RFLP | 6 |
| He | 2009 | China | Asian | 202/404 | 606 | HB | HCC | PCR-RFLP | 7 |
| Zhang | 2009 | China | Asian | 117/143 | 260 | HB | PC | PCR-PAGE | 8 |
| Zhou | 2010 | China | Asian | 233/365 | 598 | Mixed | CSCC | PCR-PAGE | 7 |
| Andersen | 2010 | Denmark | Caucasian | 378/756 | 1134 | PB | CRC | TaqMan | 8 |
| Tang | 2010 | China | Asian | 207/228 | 435 | HB | BC | PCR-PAGE | 7 |
| Song | 2011 | China | Asian | 1,001/1,005 | 2006 | PB | CRC | PCR-RFLP | 8 |
| Fan | 2011 | China | Asian | 179/223 | 402 | PB | OC | PCR-CGE | 7 |
| Lin | 2012 | China | Asian | 462/520 | 982 | HB | OSCC | TaqMan | 8 |
| Ungerback | 2012 | Sweden | Caucasian | 348/622 | 966 | PB | CRC | TaqMan | 8 |
| Huang | 2013 | China | Asian | 1056/1056 | 2112 | HB | LC | TaqMan | 7 |
| Huang | 2013 | China | Asian | 503/623 | 1126 | HB | LC | TaqMan | 7 |
| Cheng | 2013 | China | Asian | 135/520 | 655 | HB | HCC | TaqMan | 8 |
| Li | 2013 | China | Asian | 609/640 | 1249 | HB | BC | TaqMan | 8 |
| Oltulu | 2014 | Turkey | Caucasian | 95/99 | 194 | NA | LC | PCR-RFLP | 7 |
| Kopp | 2013 | Denmark | Caucasian | 334/334 | 668 | PB | PC | TaqMan | 8 |
| Huo | 2013 | China | Asian | 187/221 | 408 | HB | OC | MassARRAY | 7 |
| Vangsted | 2012 | Denmark | Caucasian | 328/1696 | 2024 | PB | MM | Taqman | 6 |
| Zhou | 2009 | China | Asian | 163/203 | 366 | HB | NPC | PCR-PAGE | 8 |
| Han | 2015 | China | Asian | 936/936 | 1872 | PB | PC | PCR-RFLP | 8 |
| Li | 2015 | China | Asian | 220/222 | 442 | HB | Osteosarcoma | PCR-RFLP | 7 |
| Liu | 2015 | China | Asian | 906/1072 | 1978 | HB | NPC | TaqMan | 7 |
| Liu | 2015 | China | Asian | 684/907 | 1591 | HB | NPC | TaqMan | 7 |
| Wang | 2015 | China | Asian | 421/425 | 846 | HB | LC | PCR-RFLP | 8 |
| Lu | 2015 | China | Asian | 687/687 | 1374 | HB | OC | PCR-RFLP | 7 |
| Kopp | 2015 | Denmark | Caucasian | 1,010/1,829 | 2634 | PB | CRC | PCR-KASP | 6 |
| Chen | 2015 | China | Asian | 411/438 | 852 | HB | OC | MassARRAY | 7 |
| Zhang | 2014 | China | Asian | 208/1606 | 2230 | HB | HCC | PCR-RFLP | 6 |
| Hua | 2014 | China | Asian | 401/433 | 834 | HB | GC | MassARRAY | 8 |
| Wang | 2015 | China | Asian | 352/459 | 811 | HB | PTC | PCR-PAGE | 8 |
| Li | 2015 | China | Asian | 730/780 | 1510 | HB | BC | TaqMan | 8 |
| Li | 2015 | China | Asian | 1216/1588 | 2804 | HB | RCC | TaqMan | 8 |
| Li | 2015 | China | Asian | 820/945 | 1765 | HB | PC | TaqMan | 8 |
| Rybka | 2016 | Poland | Caucasian | 62/126 | 188 | NA | AML | PCR-CGE | 6 |
| Eskandari | 2016 | Iran | Asian | 236/203 | 439 | PB | BC | AS-PCR | 9 |
| Zhang | 2015 | China | Asian | 718/718 | 1436 | PB | LC | PCR-RFLP | 8 |
AS-PCR, Allele-Specific polymerase chain reaction; PCR-CGE, polymerase chain reaction with capillary gel electrophoresis; PCR-RFLP, polymerase chain reaction-restriction fragment length polymorphism; PCR-PAGE, polymerase chain reaction-polyacrylamide gel electrophoresis; HB, hospital-based study; PB, population-based study; NA, not available; BC, bladder cancer; PC, prostate cancer; OC, ovarian cancer; LC, lung cancer; HCC, hepatocellular carcinoma; MM, multiple myeloma; OSCC, oral squamous cell carcinoma; CSCC, cervical squamous cell carcinoma; CRC, colorectal cancer; NPC, nasopharyngeal carcinoma; GC, gastric cancer; GNT, gastroenteropancreatic neuroendocrine tumor; HNSCC, squamous cell carcinomas of the head and neck region; BCLL, B cell chronic lymphocytic leukemia; RCC, renal cell carcinoma; ESCC, esophageal squamous cell carcinoma; BRC, breast cancer; PTC, papillary thyroid carcinoma; AML, acute myeloid leukaemia.