Table 1. Baseline characteristics of studies included in this meta-analysis.
| Study (year) | Country | Study design | Stage | Histology | Sample size | Median age | Cut-off value | Determine the cut-off value | Survival analysis | Source of HR | Adjusted | Follow-up (months) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Peng 2017 | China | R | All | All | 1360 | 55 (14–87) | PLR: 164/176 LMR: 4.3 | ROC analysis | OS, PFS | SC | No | 2–108 |
| Ishihara 2017 | Japan | R | M | All | 63 | – | PLR: 183 | Maximum Youden index | OS, PFS | Rep | Yes | –60 |
| Chrom 2017 | Poland | R | M | All | 321 | 62 (22–85) | PLR: 157 | IMDC criteria | OS | Rep | Yes | –72 |
| Xia 2016 | China | R | NM | Clear cell | 985 | 55 (21–81) | LMR: 3.0 | 25th percentile | OS, RFS | DE | No | 3–60 |
| Park 2016 | Korea | R | M | Clear cell | 63 | 63.1 (56–70.5) | PLR: 150 | ROC analysis | OS, PFS | Rep | Yes | – |
| Hu 2016 | China | R | All | All | 484 | 56 (21–81) | PLR: 185 | ROC analysis | OS | Rep | Yes | –60 |
| Gu 2016 | China | R | M | Clear cell | 145 | 56 (47–63) | LMR: 3.0 | ROC analysis | OS, PFS | Rep | Yes | –60 |
| Gu 2016 | China | R | All | All | 103 | 56 (16–79) | PLR: 132 LMR: 3.1 | ROC analysis | OS | Rep | Yes | –110 |
| Lucca 2015 | Austria | R | NM | Clear cell | 430 | 65.5 (57–73) | PLR: 145 LMR: 2.5 | Maximum survival difference | RFS | Rep | Yes | –48 |
| Gunduz 2015 | Turkey | R | M | All | 94 | 58 (33–95) | PLR: 210 | Maximum survival difference | OS, PFS | SC | No | –40 |
| Chang 2015 | China | R | NM | Clear cell | 430 | 56 (46–63) | LMR: 3.25 | 25th percentile | RFS | Rep | Yes | –72 |
| Chang 2015 | China | R | All | Clear cell | 441 | 56 (46–63) | LMR: 4.44 | Median | OS | SC | No | –72 |
| Keskin 2014 | Turkey | R | All | All | 211 | 61.2 (11.8)a | PLR: 151 | Median | OS | SC | No | –24 |
| Hutterer 2014 | Austria | R | NM | Clear cell | 678 | 65 (20–88) | LMR: 3.0 | ROC analysis | OS, RFS | Rep | Yes | 0–130 |
| Fox 2013 | Australia | P | M | All | 362 | 62 (19–84) | PLR: 195 | Median | OS | Rep | No | –40 |
| Dirican 2013 | Turkey | R | M | All | 53 | 61 (40–79) | PLR: 134 | Regression tree analysis | OS | DE | No | –40 |
Notes: study design: R retrospective, P prospective. Stage: All non-metastatic and metastatic, M metastatic, NM non-metastatic. Histology: All clear cell and non-clear cell. Survival analysis: OS overall survival, PFS progression-free survival, RFS recurrence-free survival. Source of HR: SC survival curve, Rep reported, DE data extrapolated.
-, not reported.
a shown as mean (SD).