Table 1. General characteristics of the included studies.
| First author | Country | Ethnicity | Age | Stage | Method | Sample | Cancer | Benign lesions | Normal | OS | Expression |
|---|---|---|---|---|---|---|---|---|---|---|---|
| N (M %) | N (M %) | N (M %) | |||||||||
| Ferguson 2000 [17] | USA | European | NA | NA | MSP | Tissue | 82 (91.5) | 6 (0) | NA | Negative | |
| Umbricht 2001 [28] | USA | European | NA | NA | MSP | Tissue | 43 (90.7) | 8 (37.5) | 10 (0) | NA | ND |
| Jing 2007 [23] | China | Asian | 32–73 | 0–3 | MSP | Tissue | 38 (86.8) | 20 (0) | 20 (0) | NA | ND |
| Jing 2007 [23] | China | Asian | 32–73 | 0–3 | MSP | Blood | 38 (55.3) | 50 (0) | NA | ND | |
| Jeronimo 2008 [22] | Portugal | European | 63 | 1–4 | qMSP | Tissue | 66 (100) | 24 (79.2) | 12 (100) | NA | ND |
| Jing 2008 [27] | China | Asian | 49.1 | NA | MSP | Blood | 102 (82.4) | 20 (0) | NS | ND | |
| Luo 2010 [16] | China | Asian | 33–74 | NA | MSP | Tissue | 68 (89.7) | 13 (15.4) | 10 (0) | NS | Negative |
| Mirza 2010 [21] | India | European | 50 | 1–3 | MSP | Tissue | 100 (61) | 15 (20) | NA | NS | |
| Mirza 2010 [21] | India | European | 50 | 1–3 | MSP | Blood | 100 (56) | 30 (6.7) | NA | ND | |
| Gheibi 2012 [25] | Iran | European | 51.7 | NA | MSP | Tissue | 20 (70) | 20 (20) | NA | ND | |
| Sharma 2012 [26] | India | European | 32–76 | NA | MSP | Blood | 30 (83.3) | 30 (0) | NA | ND | |
| Wang 2014 [24] | China | Asian | 56.2 | NA | MSP | Blood | 108 (58.3) | 180 (10) | NA | ND | |
| Shan 2016 [20] | China | Asian | NA | NA | qMSP | Blood | 268 (73.5) | 236 (61) | 245 (58.4) | NA | ND |
MSP: methylation-specific polymerase chain reaction; qMSP: quantitative methylation-specific polymerase chain reaction; M: methylation; N: sample size, NA: not applicable; NS: not significant; ND: not done; OS: overall survival.