Table 1. Main characteristics of included studies.
| Author | Year | Country | Methods | Histology | Tumor location | Stage (TNM) | Grade | Smoking status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NCT | Ade | CRC | Proximal | Distal | I+II | III+IV | L | H | + | - | ||||
| Michailidi [33] | 2015 | Greece | MSP | 12/14 | - | 18/61 | - | - | - | - | - | - | - | - |
| Samaei [34] | 2014 | Iran | MSP | 0/125 | - | 44/125 | 29/36 | 18/50 | 24/56 | 22/69 | 34/100 | 10/25 | - | - |
| Dimberg [35] | 2013 | Sweden/Vietnam | MSP | 66/101 | - | 50/101 | - | - | - | - | - | - | - | - |
| Pack [36] | 2013 | Korea | MSP | 2/10 | 6/10 | - | - | - | - | - | - | - | - | - |
| Qiu [37] | 2014 | China | MSP | 1/10 | 45/67 | 44/70 | 21/35 | 23/35 | - | - | - | - | - | - |
| Gay [38] | 2012 | UK | Pyrosequencing | - | - | - | 22/59 | 48/112 | 22/87 | 14/69 | 61/141 | 6/25 | - | - |
| Kang [39] | 2012 | Korea | Q-MSP | 2/14 | - | 52/100 | - | - | 28/52 | 24/48 | - | - | 12/20 | 40/80 |
| Leong [40] | 2011 | UK | Q-MSP | 1/19 | 22/51 | - | - | |||||||
| Naghibalhossaini [41] | 2011 | Iran | MSP | - | - | - | 30/30 | 73/80 | 66/71 | 26/28 | 48/49 | 42/48 | 53/56 | 50/54 |
| Sameer [42] | 2011 | Kashmir | MSP | - | - | - | - | - | - | - | 9/38 | 38/48 | 33/55 | 14/31 |
| Vasovcak [43] | 2011 | Czech Republic | MS-MLPA | - | - | - | 26/34 | 45/60 | 38/56 | 30/44 | - | - | - | - |
| Belshaw [44] | 2010 | UK | Q-MSP | 2/8 | - | 2/5 | - | - | - | - | - | - | - | - |
| Kim [45] | 2010 | Korea | Pyrosequencing | - | - | - | 9/68 | 36/217 | 28/169 | 24/116 | 40/253 | 5/32 | - | - |
| Kamiyama [46] | 2009 | Japan | Q-MSP | - | - | - | 6/20 | 10/25 | - | - | - | - | - | - |
| Derks [47] | 2006 | European/USA | MSP | 3/18 | 17/34 | 10/18 | - | - | - | - | - | - | ||
| Iacopetta [27] | 2006 | Australia | Q-MSP | - | - | - | 24/90 | 33/106 | - | - | 41/122 | 6/28 | - | - |
| Brandes [48] | 2005 | Netherlands | MSP | - | - | - | - | - | 19/30 | 6/14 | - | - | - | - |
| Chen [49] | 2005 | Germany | MSP | 0/14 | - | 17/34 | - | - | - | - | - | - | - | - |
| Ebert [50] | 2005 | Germany | MSP | 0/21 | 10/47 | - | - | - | - | - | - | - | - | |
| Kim [51] | 2005 | Korea | MSP | 6/40 | 7/36 | - | - | - | - | - | - | - | - | |
| Bai [52] | 2004 | China | MSP | 1/34 | 28/47 | - | - | - | - | - | - | - | - | |
| Lee [53] | 2004 | Korea | MSP | 3/24 | 34/95 | 76/149 | 29/56 | 47/93 | - | - | - | - | - | - |
| Lind [54] | 2004 | Norway | MSP | - | - | - | 7/18 | 13/37 | 13/31 | 8/26 | 16/44 | 4/11 | - | - |
| Xu [55] | 2004 | China | MSP | 0/6 | 2/8 | 5/65 | - | - | - | - | - | - | - | - |
MSP: methylation-specific PCR; MS-MLPA: methylation specific multiplex ligation-dependent probe amplification, NCT: normal control tissue; Ade: adenoma; CRC: colorectal carcinoma; L: low grade; H: high grade.