Table 1. Major characteristics of enrolled studies.
| No. | Study | Number | Sex (M/F) | region | Detection method | Target gene | HR | Follow up | AT | SS | ST | BV (ml) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | WK Leung8 | 60 | / | Hongkong | MSP | APC/E-cadherin | OS:3.38(1.42-8.05) (F) | 8 (0–40) | Methylation | Serum | BS | 0.8 |
| 2 | Mohammad R.A.9 | 52 | 38/14 | Iran | MSP | P16 | / | / | Hypermethylation | Serum | BS | / |
| 3 | Wang YC10 | 47 | 29/18 | China | MSP | RASSF1A | / | / | Hypermethylation | serum | BS | 5 |
| 4 | Chouhei.S11 | 65 | 37/28 | Japan | qMSP | RUNX3 | / | / | Methylation | Serum | BS | / |
| 5 | Kenji H.12 | 73 | 57/16 | Japan | qMSP | TFPI2 | / | / | Methylation | Serum | TOS | / |
| 6 | Ioanna B.13 | 73 | 51/22 | Greece | MSP | SOX17 | OS:1.60 (1.0–2.55) (F) | 56 (20–111) | Methylation | Serum | BS | / |
| 7 | Yang QF14 | 40 | 33/7 | China | BGS | BCL6B | OS:1.86 (0.68–5.10) (K) | / | Hypermethylation | Plasma | BS | 1 |
| 8 | Zhi QL15 | 202 | 120/82 | China | MSP | XAF1 | DFS:5.71 (3.474–9.383) (K) | / | Methylation | Serum | BS | / |
| 9 | Han J16 | 92 | 53/39 | China | qMSP | MINT2 | DFS:3.362 (1.779–5.981) (D) | / | Methylation | Serum | BS | / |
| 10 | Wu YC | 92 | 53/39 | China | qMSP | P16 | DFS: 2.31 (1.00–5.37) (K) | / | Methylation | Serum | BS | / |
| 11 | Yu JL17 | 92 | 54/38 | China | MSP | TIMP-3 | DFS:97.376 (8.388–1130.378) (D) | / | Methylation | Serum | BS | / |
| 12 | Zhang H18 | 41 | 30/11 | China | MSP | Spastic paraplegia-20 | / | / | Hypermethylation | BS | 2 | |
| 13 | Chang L19 | 42 | 30/12 | China | MSP | SFRP1 | / | / | Methylation | Serum | BS | 5 |
| 14 | Ioanna B. (APC)20 | 73 | 51/22 | Greece | MSP | APC | OS: 2.94(1.33-6.53) (F) | 56 (12–111) | Methylation | Serum | BS | / |
| Ioanna B.(RASSF1A)20 | 73 | 51/22 | Greece | MSP | RASSF1A | OS: 0.87(0.46-1.66) (F) |
56 (12–111) | Methylation | Serum | BS | / | |
| 15 | Charinya P (PCDH10)21 | 101 | 44/57 | Tailand | MSP | PCDH10 | OS:3.47(1.69-7.11) (F) | / | Methylation | plasma | BS | / |
| Charinya P (RASSF1A) 21 | 101 | 44/57 | Thailand | MSP | RASSF1A | OS:1.66(0.98-2.83) (F) | / | Methylation | plasma | BS | / | |
| 16 | Li WH22 | 48 (25) | 39/9 | China | MSP | OSR2:VAV3:PPFIA3 | / | / | Methylation | Serum | BS | 0.4 |
K: extracted and calculated from the Kaplan-Meier curves in the studies; F: calculated by the formula provided by Parmar et al37. D: directly extracted by the authors in the studies; HR: hazard ratio; AT: alteration type; SS: sample source; ST: sample time; BV: blood volume; MSP: methylation-specific PCR; qMSP: quantitative methylation-specific PCR; BS: before surgery; TOS: time of surgery; OS: overall survival; DFS: disease-free survival.