Table 1. Basic characteristics of the studies enrolled.
| No. | First author | Year | Country | Sample size | Mean Age (year) | Duration of follow-up (month) | Survival condition | Testing methods | Cut-off value | Sources | With chemotherapy | Segment type | RR (95%CI) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Shangnao Xie [18] | 2014 | China | 975 | 48.5 (23–71) | NM | PFS | ELISA | 80 u/l | Serum | Y | M30 | 1.61 (1.20–2.30) |
| OS | ELISA | 1.54 (1.18–2.71) | |||||||||||
| 2 | Faruk Tas [19] | 2014 | Turkey | 80 | 52 (30–81) | 36.5 | OS | ELISA | Serum | Y | M30 | 1.51 (0.79–2.90) | |
| 3 | B. K. Linderholm [20] | 2013 | Sweden | 409 | 63 | 122.4 | PFS | ELISA | Serum | Y | M30 | 3.30 (1.51–7.22) | |
| 4 | Natalia Krawczyk [21] | 2014 | Germany | 298 | 59 (24–90) | 44 (10–88) | OS | IHC | Serum | N | M30 | 3.38 (1.46–7.8) | |
| 5 | Gerhard Schaller [22] | 1996 | Germany | 43 | 59 (23–91) | 80 (3–98) | OS | IHC | Tissue | N | M65 | 0.17 (0.01–2.92) | |
| 6 | Ute Woelfle [23] | 2004 | Germany | 1458 | NM | 51 (1–150) | OS | IHC | Tissue | N | M65 | 0.50 (0.38–0.66) | |
| 7 | Soo Kyung Ahn [24] | 2013 | Korea | 1477 | 48 (22–89) | 66.3 (0–128) | PFS | ELISA | 80u/l | Serum | N | M30 | 1.64 (1.20–2.21) |
| OS | ELISA | 1.57 (1.06–2.35) | |||||||||||
| 8 | Masahiro Takada [25] | 2004 | Japan | 72 | 51 (28–74) | 32.4 | OS | IHC | Tissue | Y | M30 | 0.30 (0.11–0.85) | |
| 9 | Maria Hagg Olofssion [26] | 2007 | Japan | 45 | NM | NM | OS | ELISA | Serum | Y | M65 | 0.21 (0.03–1.74) |
Abbreviations: ELISA, enzyme-linked immune sorbent assay; IHC, immunohistochemistry; NM, not mentioned; OS, overall survival; PFS, progress-free survival.