Table 1.
Characteristics of studies included in this meta-analysis
| Study | Year | Region | Sample | Cancer | Method | Outcome | NOS score |
| Okada et al7 | 2021 | Japan | 114 | Pancreatic ductal adenocarcinoma | qRT-PCR | OS | 8 |
| Okada et al22 | 2021 | Japan | 121 | Pancreatic ductal adenocarcinoma | qRT-PCR | OS | 8 |
| Pei et al16 | 2019 | China | 121 | Cholangiocarcinoma | IHC | – | 7 |
| Liang et al17 | 2018 | China | 64 | Oesophageal squamous cell carcinoma | qRT-PCR | OS | 7 |
| Zhan et al23 | 2019 | China | 473 | Papillary thyroid cancer | RNA-seq | PFS | 6 |
| Zhou et al13 | 2018 | China | 114 | Penile squamous cell carcinoma | IHC | DSS | 7 |
| Huang et al6 | 2017 | China | 49 | Colorectal cancer | IHC | – | 6 |
DSS, disease-specific survival; IHC, immunocytochemistry; NOS, Newcastle-Ottawa scale; OS, overall survival; PFS, progression-free survival; qRT-PCR, quantitative real-time PCR.