1.
Characteristics of the studies included in the meta-analysis
| Author | Year | Country | Tumor type | No. of patients | Stage | Detection methods | Cutoff-value | PD-L1 positive | Outcome | HR estimation | Prognostic value | Quality score |
| DLBCL: diffuse large B-cell lymphoma, NKTCL: natural killer/T-cell lymphoma, ATLL: adult T-cell leukemia/lymphoma, ENKTL: extranodal NK/T-cell lymphoma, IHC: immunohistochemistry, OS: overall survival, HR: hazard ratio, K-M: Kaplan–Meier curve, NR: not relevant. | ||||||||||||
| Kiyasu et al.15 | 2015 | Japan | DLBCL | 1,253 | I–IV | IHC | 30% | 37%
(461/1253) |
OS | HR | Poor | 6 |
| Bi
et al.16 |
2016 | China | NKTCL | 77 | I–II | IHC | 38% | 33.8%
(26/77) |
OS | HR | Poor | 8 |
| Dong
et al.17 |
2016 | China | DLBCL | 100 | I–IV | IHC | 5% | 54%
(54/100) |
OS | HR | Poor | 8 |
| Kim
et al.20 |
2016 | Korea | NKTCL | 73 | I–IV | IHC | 10% | 61.6%
(45/73) |
OS | HR | Good | 7 |
| Kwon
et al.21 |
2016 | Korea | DLBCL | 126 | I–IV | IHC | 10% | 61.1%
(77/126) |
OS | HR | NR | 6 |
| Miyoshi
et al.22 |
2016 | Japan | ATLL | 135 | I–IV | IHC | 50% | 7%
(10/135) |
OS | HR | Good | 6 |
| Xing
et al.18 |
2016 | USA | DLBCL | 86 | I–IV | IHC | 30% | 16%
(14/86) |
OS | HR | Poor | 6 |
| Fang
et al.19 |
2017 | China | DLBCL | 76 | I–IV | IHC | 10% | 26.3%%
(20/76) |
OS | HR | Poor | 6 |
| Jo
et al.23 |
2017 | Germany | ENKTL | 79 | I–III | IHC | 5% | 79.7%
(63/79) |
OS | K-M | NR | 7 |