Table 1. Characteristics of the studies included in the meta-analysis.
| Study | Year | Ethnicity | Cases | Controls source | Genotypingmethod | No. ofcases/controls | Mean age ofcases/controls | Sex distribution in cases/controls (male %) |
| Ma [20] | 1999 | American | CRC | Population | RFLP | 356/476 | NA/NA | 100/100 |
| Matsuo [21] | 2002 | Japanese | CRC | Hospital | RFLP | 142/241 | NA/NA | 58.9/49.0 |
| Le Marchand [22] | 2002 | American | CRC | Population | RFLP | 539/652 | 66.0/67.0 | 60.8/57.9 |
| Ulvik [23] | 2004 | Norwegian | CRC | Population | Taqman | 2168/2192 | NA/NA | 63.5/63.5 |
| Ulrich [24] | 2005 | American | CRC | Population | Taqman | 1600/1962 | 64.9/65.0 | 56.0/53.0 |
| Matsuo [25] | 2005 | Japanese | CRC | Hospital | RFLP | 257/771 | 58.8/59.0 | 63.0/63.0 |
| Chen [26] | 2006 | Chinese | CRC | Population | RFLP | 199/413 | 62.5/61.9 | 50.8/51.7 |
| Koushik [27] | 2006 | American | CRC | Population | Taqman | 363/804 | 68.2/68.0 | 47.6/42.0 |
| Curtin [28] | 2007 | American | CRC | Population | Taqman | 916/1974 | NA/NA | NA/NA |
| Steck [29] | 2008 | American | CRC | Population | Taqman | 546/855 | 63.8/65.9 | NA/NA |
| Zhang [30] | 2008 | Chinese | CRC | Hospital | RFLP | 298/300 | 57.7/57.6 | 56.3/56.7 |
| Guerreiro [31] | 2008 | Portuguese | CRC | Population | Taqman | 196/200 | 64.2/62.2 | 53.1/53.0 |
| Theodoratou [32] | 2008 | Scottish | CRC | Population | Array | 999/1010 | 62.3/62.7 | 57.3/56.9 |
| Zhang [33] | 2009 | Chinese | CRC | Hospital | RFLP | 476/835 | 54.3/52.0 | 57.1/55.1 |
| de Vogel [34] | 2009 | Dutch | CRC | Population | SNaPShot | 696/1805 | NA/NA | 55.0/50.2 |
| Levine [35] | 2010 | American | CRC | Population | iPLEX | 1806/2879 | 53.5/54.0 | 51.3/44.4 |
| Eussen [36] | 2010 | European | CRC | Population | Mass spectrometry | 1329/2364 | 58.9/58.7 | 51.0/53.0 |
| Guimarães [37] | 2011 | Brazilian | CRC | Population | RFLP | 113/188 | 59.0/54.0 | 53.1/64.4 |
| Jokić [38] | 2011 | Croatian | CRC | Population | Taqman | 300/300 | 62.2/61.4 | 54.0/50.6 |
| Kim [39] | 2011 | Korean | CRC | Hospital | RFLP | 67/53 | 61.8/58.7 | 52.2/43.4 |
| Martinelli [40] | 2012 | Italian | CRC | Population | RFLP | 71/80 | 69.0/58.0 | 59.2/53.8 |
| Pufulete [41] | 2003 | British | CRC, CRA | Hospital | RFLP | 63/76 | 68.9/58.0 | 46.0/45.0 |
| Goode [42] | 2004 | American | CRA | Population | Taqman | 513/609 | NA/NA | 63.0/38.8 |
| Hazra [43] | 2007 | American | CRA | Population | Taqman | 529/532 | NA/NA | 0/0 |
| Yamaji [44] | 2009 | Japanese | CRA | Population | Taqman | 723/607 | 61.0/60.0 | 67.5/65.4 |
| de Vogel [45] | 2011 | Norwegian | CRA | Population | Mass spectrometry | 1713/8355 | 56.9/56.1 | 60.6/47.0 |
| Han [46] | 2012 | American | CRA | Population | Taqman | 1331/1501 | NA/NA | NA/NA |