Table 1.
Characteristics of the studies included in the meta-analysis.
| Author | Year | Country | No. of patients | Ethnicity | Sex (M/F) | Tumor location | Follow-up (months) Median (range) |
Study design | Treatment | Survival outcome | PD-L1 (+) n (%) |
NOS score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ahn, S. | 2019 | Korea | 183 | Asian | 122/61 | eCCA | 27.2 | Retrospective | Surgery | OS, DFS | 31 (16.9) | 7 |
| Arkenau, H. T. | 2018 | UK | 26 | Caucasian | 8/18 | CCA | 6.4 (4.1-13.2) | Prospective | Targeted therapy + immunotherapy | OS, DFS | 12 (46.2) | 8 |
| Dong, Z. T. | 2020 | China | 125 | Asian | 58/77 | iCCA | 16 (5-63) | Retrospective | Surgery | OS, DFS | 52 (41.6) | 7 |
| Gani, F. | 2016 | USA | 54 | Caucasian | 17/37 | iCCA | NR | Retrospective | Surgery | OS | 39 (72.2) | 6 |
| Gou, M. M. | 2019 | China | 30 | Asian | 18/12 | CCA | To Sep 2018 | Retrospective | Immunotherapy | DFS | 11 (36.6) | 7 |
| Jing, C. Y. | 2019 | China | 153 | Asian | NR | iCCA | 47.5 (1-88.4) | Retrospective | Surgery | OS | 43 (28.1) | 7 |
| Kim, R. | 2018 | USA | 44 | Caucasian | 23/21 | eCCA | NR | Retrospective | Surgery | OS | 10 (22.7) | 6 |
| Kitano, Y. | 2020 | Japan | 177 | Asian | 115/62 | CCA | 78.7 | Retrospective | Surgery | OS | 54 (30.5) | 6 |
| Kriegsmann, M. | 2019 | Germany | 170 | Caucasian | 109/61 | CCA | NR | Retrospective | Surgery | OS | 19 (11.1) | 6 |
| Lim, Y. J. | 2015 | Korea | 83 | Asian | 61/22 | eCCA | 27 | Retrospective | Surgery | OS, DFS | 56 (83) | 7 |
| Lu, J. C. | 2019 | China | 320 | Asian | 19/129 | iCCA | To Oct 2016 | Retrospective | Surgery | OS, DFS | 99 (30.9) | 7 |
| Ma, K. | 2017 | China | 70 | Asian | 38/32 | eCCA | To Mar 2015 | Retrospective | Surgery | OS | 30 (42.9) | 7 |
| Sangkhamanon, S. | 2017 | Thailand | 46 | Asian | 33/13 | CCA | NR | Retrospective | Surgery | OS | 18 (39.1) | 6 |
| Tamai, K. | 2014 | Japan | 91 | Asian | 62/29 | eCCA | NR | Retrospective | Surgery | OS | 77 (84.6) | 6 |
| Ueno, T. | 2018 | Japan | 117 | Asian | 93/24 | eCCA | 27 (0-189) | Retrospective | Surgery | OS | 10 (8.5) | 7 |
| Walter, D. | 2017 | Germany | 69 | Caucasian | 50/19 | eCCA | 23 (0-100) | Retrospective | Surgery | OS | 8 (11.6) | 7 |
| Yu, F. | 2019 | China | 62 | Asian | 41/21 | eCCA | NR | Retrospective | Surgery | OS, DFS | 20 (32.3) | 6 |
| Zhu, Y. | 2018 | China | 192 | Asian | 115/77 | iCCA | 24 (0.4-85) | Retrospective | Surgery | OS, DFS | 34 (17.7) | 7 |
CCA: cholangiocarcinoma; eCCA: extrahepatic cholangiocarcinoma; iCCA: intrahepatic cholangiocarcinoma; NR: not reported; OS: overall survival; DFS: disease-free survival; NOS: Newcastle-Ottawa scale. CCA includes iCCA and eCCA.