Table 1.
Main characteristics of all studies included in the meta-analysis
| Study | Country | Case number | High expression (%) | Pathological type | Molecular type | Staining location | Tumor stage | Follow-up (months) | Cut-off value | Multivariate analysis | HRs provided from | Outcome | NOS score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heublein 2017 [16] | Germany | 117 | 57 (48.7) | NR | Multiple | Nucleus | Multiple | Mean 81.8 | IRS > 4.14 | No | SC | OS | 6 |
| Huss 2019 [17] | Sweden | 678 | 553 (81.6) | Multiple | Multiple | Nucleus | Multiple | NR | Positive cells > 10% | No | Report | CSS | 8 |
| Al-Azhri 2017 [18] | America | 1114 | 283 (25.5) | NR | Multiple | Nucleus | Multiple | Median 72 (3–201) | IRS > 5 | Yes | Report | OS/PFS/CSS | 8 |
| Ditsch 2012 [19] | Germany | 82 | 75 (91.5) | Invasive ductal | Multiple | Nucleus and cytoplasm | NR | NR | IRS > 5 | Yes | Report | OS/DFS | 7 |
| Soljic 2017 [20] | Yugoslavia | 96 | 26 (27) | Multiple | Triple negative | Nucleus and cytoplasm | I-IIIa | Mean 69 (3–143) | NR | No | Report | OS/DFS | 7 |
| Ishida 2018 [21] | Japan | 144 | NR | NR | NR | Nucleus | I-III | Mean 7.7 (6–129) | NR | No | Report | DFS | 8 |
| Zehni (unifocal) 2019 [22] | Germany | 155 | 66 (42.6) | Multiple | Multiple | Nucleus | NR | NR | IRS > 25 | Yes | Report | OS/DFS | 7 |
| Zehni (multifocal) 2019 [22] | Germany | 117 | 60 (51.3) | Multiple | Multiple | Nucleus | NR | NR | IRS > 25 | Yes | Report | OS/DFS | 7 |
NR Not report, IRS Immunoreactive score, HR Hazard ratio, SC Survival curve, OS Overall survival, CSS Cancer-specific survival, PFS Progression-free survival, DFS Disease-free survival, NOS Newcastle-Ottawa Quality Assessment Scale