Table 2. Summary of PD-L1 expression rate in subgroup analysis.
| Subgroup | No. of studies | PD-L1 expresson rate (95% CI) / % | Subgroup | No. of studies | PD-L1 expression rate (95% CI) / % |
|---|---|---|---|---|---|
| Tumor type | Patients' origin | ||||
| adrenocortical carcinoma | 1 | 10.7 (−0. 7-22.1) | Asian | 37 | 52.3 (46.9-57.6) |
| Breast cancer | 4 | 23.7 (19.9-27.4) | Non-Asian | 24 | 32.7 (24.3- 41.1) |
| Cervical carcinoma | 1 | 19.1 (11.9-26.3) | Antibody-Type | ||
| Clear cell renal cell carcinoma | 4 | 38.1 (22.0-54.2) | Monoclonal antibody | 39 | 39.6 (32.8-46.3) |
| Non-clear cell renal cell carcinoma | 1 | 10.9 (4.8-17.0) | Polyclonal antibody | 18 | 57.2 (49.8-64.6) |
| Colorectal cancer | 6 | 47.7 (45.4-49.9) | IHC evaluation | ||
| Esophageal cancer | 2 | 38.6 (30.7-46.6) | Percentage | 35 | 42.8 (31.5-54.2) |
| Gastric carcinoma | 4 | 49.2 (30.8-67.6) | H-score | 20 | 47.7 (40.5-54.9) |
| Hepatocellular carcinoma | 2 | 58.5 (−7.5-124.5) | DIA | 3 | 24.9 (20.4-29.3) |
| Small cell lung cancer | 1 | 71.6 (62.8-80.3) | NA | 3 | 55.6 (35.7-75.4) |
| Non-small cell lung cancer | 13 | 51.7 (33.1-70.3) | IHC evaluation-Percentage | ||
| Pancreatic cancer | 4 | 47.6 (40.5-54.6) | Cut-off = 5% | 19 | 34.3 (26.5-42.1) |
| plural mesothelium | 1 | 20.8 (11.7-29.8) | Cut-off = 10% | 10 | 56.5 (49.5-63.6) |
| Head and neck cancer | 4 | 54.4 (44.8-60.0) | Others | 6 | 42.9 (7.3-78.5) |
| Skin cancer | 5 | 42.8 (32.5-53.1) | IHC evaluation-H-score | ||
| Thymic carcinoma | 1 | 34.5 (26.6-42.4) | Cut-off ≤ 50 | 10 | 54.8 (43.1-66.5) |
| Urothelial carcinoma | 6 | 44.9 (24.4-65.4) | Cut-off > 50 | 8 | 37.1 (27.8-46.5) |
Abbreviations: CI = confidence interval; IHC = immunohistochemistry; DIA = digital image analysis; NA = not available; PD-L1 = programmed cell death 1ligand 1.