Table 1.
Main characteristics of included studies about PD-L1 in this meta-analysis
| Author | Year | Origin | Range of year | Categories | No. of patients | Cut off value for PD-L1 positive | No. of positive | Detected area | Endpoints | Detection method | Hazard ratio | Calculation of HRs | Quality score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cao et al. | 2018 | China | NA | Primary | 108 | H-score > 140 | 18 | TC | OS, PFS | FFPE, IHC | K–M curve | Univariate | 7 |
| Chan et al. | 2017 | Hong Kong | 2005–2009 | primary | 161 | ≥ 1%, ≥ 5% | 122, 38 | TC or IC | OS, PFS | FFPE, IHC | Report | Univariate and multivariate | 7 |
| Chang et al. | 2017 | Philippines | 2008–2011 | NA | 56 | ≥ 1%, ≥ 5% | 36, 30 | TC | OS | FFPE, IHC | Report | Univariate | 7 |
| Fang et al. | 2014 | China | 2004–2008 | Primary | 139 | H-score > 35 | 62 | TC and mesenchymal cells | DFS | FFPE, IHC | Report | Univariate | 8 |
| Larbcharoensub et al. | 2018 | Thailand | 2007–2012 | Primary | 114 | ≥ 5% | 81 | TC or IC | OS | FFPE, IHC | K–M curve | Univariate | 8 |
| Lee et al. | 2016 | Hong Kong | 2005–2009 | Primary | 104 | > 25% | 22 | TC | OS, PFS, DMFS | FFPE, IHC | Report | Univariate and multivariate | 9 |
| Li et al. | 2017 | China | 2009–2015 | Primary | 120 | H-score ≥ 5 | 54 | TC | OS, DFS | FFPE, IHC | K–M curve | Univariate | 6 |
| Liu et al. | 2018 | China | NA | NA | 208 | ≥ 4% (TC), ≥ 2% (IC) | 107 (TC), 131 (IC) | TC, IC, TC and IC | OS, DFS | FFPE, IHC | Report | Univariate and multivariate | 7 |
| Ono et al. | 2018 | Japan | 2000–2015 | Primary | 66 | ≥ 5% | 53 (TC), 50 (IC) | TC, IC | OS PFS | FFPE, IHC | Report | Univariate and multivariate | 8 |
| Qu et al. | 2018 | China | NA | NA | 96 | > 10% | 28 | TC | DMFS | FFPE, IHC | K–M curve | Univariate | 7 |
| Zhang et al. | 2015 | China | NA | NA | 139 | H-score > 35 | 58 | Tumor tissue | DFS | FFPE, IHC | K–M curve | Univariate | 7 |
| Zheng et al. | 2017 | China | 2010–2012 | Primary | 85 | Score ≥ 3 | 29 | TC | OS, DMFS | FFPE, IHC | Report | Multivariate | 7 |
| Zhou et al. | 2017 | China | 2001–2013 | Recurrence | 132 | H-score > 190 | 88 | TC | OS | FFPE, IHC | Report | Multivariate | 9 |
| Zhou et al. [2] | 2017 | China | 2010–2012 | Primary | 99 | H-score ≥ 155 | 61 | TC | OS | FFPE, IHC | Report | Multivariate | 9 |
| Zhu et al. | 2017 | China | 1991–2000 | Primary | 209 | ≥ 5% | 68 (TC), 98 (IC) | TC, IC | OS, DFS | FFPE, IHC | Report | Univariate and multivariate | 8 |
DFS: disease-free survival; DMFS: distant metastasis-free survival; FFPE: Formalin-Fixed and Paraffin-Embedded; HRs: hazard ratios; IC: immune cells; IHC: immunohistochemistry; K–M curve: Kaplan–Meier curve; NA: not available; No: number; OS: overall survival; PFS: progression-free survival; TC: tumor cells