Table 1. Characteristics of studies included in the meta-analysis.
| Ref | Study | Year | No. of patients | Age (median) | Method | Assay kit | HER-2 cut-off | HER-2 positive | HER-2 negative | NOS score | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Metastasis | Non metastasis | Metastasis | Non metastasis | ||||||||||
| (12) | Wang et al. | 2018 | 60 | 24 | IHC | OriGene | A1*B1>2 | 9 | 4 | 18 | 29 | 8 | |
| (13) | Qin et al. | 2017 | 45 | 28 | IHC | MXB | A2*B1≥3 | 3 | 6 | 7 | 29 | 7 | |
| (14) | Mardanpour et al. | 2016 | 28 | 26.44 | IHC | DAKO | A3≥2 | 13 | 4 | 1 | 10 | 8 | |
| (15) | Chen et al. | 2015 | 80 | 31.2 | IHC | MXB | – | 47 | 14 | 6 | 13 | 7 | |
| (16) | Becker et al. | 2013 | 27 | 13 | IHC | DAKO | A4≥2 | 1 | 2 | 7 | 17 | 7 | |
| (17) | Ma et al. | 2012 | 63 | 16 | IHC | Santa cruz | B2 | 12 | 26 | 0 | 25 | 7 | |
| (18) | Ma et al. | 2011 | 14 | 16 | IHC | Santa cruz | B2 | 3 | 0 | 5 | 6 | 8 | |
| (19) | Su et al. | 2009 | 30 | 18 | IHC | MXB | A5>1 | 3 | 15 | 2 | 10 | 7 | |
| (20) | Qiu et al. | 2006 | 69 | 17.4 | IHC | MXB | A5+B1≥4 | 19 | 9 | 10 | 31 | 8 | |
| (21) | Qiu et al. | 2006 | 38 | 17.7 | IHC | MXB | – | 10 | 5 | 6 | 17 | 7 | |
| (22) | Zhou et al. | 2003 | 25 | 14 | IHC | Ventana | A1≥2 | 7 | 4 | 5 | 9 | 8 | |
| (23) | Morris et al. | 2001 | 53 | 16.9 | IHC | DAKO | A1≥2 | 3 | 21 | 3 | 26 | 7 | |
| (24) | Kilpatrick et al. | 2001 | 41 | 29 | IHC | DAKO | B1≥2 | 14 | 26 | 0 | 1 | 7 | |
| (25) | Gorlick et al. | 1999 | 53 | 16.9 | IHC | DAKO | A2≥2 | 8 | 33 | 2 | 10 | 8 | |
| (26) | Onda et al. | 1996 | 26 | 19.9 | IHC | Nichirei Inc | – | 10 | 1 | 6 | 9 | 7 | |
A, positive cell percentage; A1, scored 1 (<25%), 2 (25–75%), 3 (>75%); A2, scored 0 (<5%), 1 (6–25%), 2 (26–50%), 3 (>50%); A3, scored 0–3+; A4, scored 0–1 (<30%), 2–3 (>30%); A5, scored 1 (>10%); B, staining intensity; B1, scored 0 (absence of staining), 1 (weak staining), 2 (moderate staining), 3 (strong staining); B2, scored by a pathologist.