Table 1.
Summary of studies included in the present meta-analysis.
| Author/Year | Region | Study design/Phase | Lung pathology | Therapy line | Intervention (No.) | Control treatment (No.) | LM status (NO.) | |
|---|---|---|---|---|---|---|---|---|
| Yes | No | |||||||
| POPLAR | Wordwide | RCT II | NSCLC | >1 | Atezolizumab (n=144) | Docetaxel (n=143) | 66 | 221 |
| OAK | Wordwide | RCT III | NSCLC | >1 | Atezolizumab (n=452) | Docetaxel (n=452) | 177 | 673 |
| IMpower131 | Wordwide | RCT III | NSCLC | 1 | Atezolizumab+CT (n=333) | CT (n=340) | 139 | 544 |
| Checkmate227 | Wordwide | RCT III | NSCLC | 1 | Nivolumab+ipilmumab (n=583) | CT (n=583) | 252 | 914 |
| IMpower130 | Wordwide | RCT III | NSCLC | 1 | Atezolizumab+CT (n=451) | CT (n=228) | 100 | 579 |
| IMpower150 | Wordwide | RCT III | NSCLC | 1 | Atezolizumab+CT+bevacizumab (n=400) |
Bevacizumab+CT (n=400) | 110 | 690 |
| Checkmate9LA | Wordwide | RCT III | NSCLC | 1 | Nivolumab+ipilmumab+CT (n=361) | CT (n=358) | 154 | 565 |
| IMpower132 | Wordwide | RCT III | NSCLC | 1 | Atezolizumab+CT (n=292) | CT (n=286) | 73 | 505 |
| NCT03594747 | China | RCT III | NSCLC | 1 | Tislelizumab+CT (n=241) | CT (n=240) | 58 | 423 |
| Keynote189 | Wordwide | RCT III | NSCLC | 1 | Pembrolizumab+CT (n=410) | CT (n=206) | 116 | 500 |
| ORIENT-12 | China | RCT III | NSCLC | 1 | Sintilimab+CT (n=179) | CT (n=178) | 14 | 165 |
| GEMSTONE-302 | China | RCT III | NSCLC | 1 | Sugemalimab+CT (n=320) | Placebo (n=159) | 39 | 18 |
| IMpower133 | Wordwide | RCT III | SCLC | 1 | Atezolizumab+CT (n=201) | CT (n=202) | 149 | 254 |
| Keynote604 | Wordwide | RCT III | SCLC | 1 | Pembrolizumab+CT (n=228) | CT (n=225) | 190 | 263 |
| Checkmate331 | Wordwide | RCT III | SCLC | >1 | Nivolumab (n=284) | CT (n=285) | 205 | 363 |
| Checkmate451 | Wordwide | RCT III | SCLC | >1 | Nivolumab+ipilmumab/Nivolumab (n=559) |
Placebo (n=275) | 325 | 509 |
| Lobefaro 2021( 32 ) | Italy | Observational trial | NSCLC | un | ICI (n=404) | – | 77 | 327 |
| MengQiao 2021 (33) | China | Observational trial | NSCLC | un | ICI/ICI+CT (n=405) | – | 29 | 203 |
| Diker 2021( 34 ) | Turkey | Observational trial | NSCLC | 1 | Pembrolizumab+CT/Pembrolizumab (n=406) | – | 16 | 28 |
| Banna 2021( 35 ) | England | Observational trial | NSCLC | 1 | Pembrolizumab (n=407) | – | 23 | 76 |
| Cortellini 2020( 37 ) | Italy | Observational trial | NSCLC | 1 | Pembrolizumab (n=410) | – | 234 | 1120 |
| Schouten 2020( 38 ) | Dutch | Observational trial | NSCLC | un | Nivolumab (n=411) | – | 43 | 205 |
| Filippo 2020 (39) | Italy | Observational trial | NSCLC | un | Nivolumab/Pembrolizumab/ Atezolizumab (n=412) |
– | 29 | 104 |
| Lim 2020 (40) | Korea | Observational trial | NSCLC | >1 | Nivolumab (n=413) | – | 32 | 267 |
| Ahn 2019 (43) | Korea | Observational trial | NSCLC | un | Nivolumab/Pembrolizumab (n=416) | – | 24 | 131 |
| CRINÒ 2019 (31) | Itally | Observational trial | NSCLC | un | Nivolumab (n=417) | – | 63 | 308 |
| Morita 2019 (44) | Japan | Observational trial | NSCLC | >1 | Nivolumab (n=418) | – | 104 | 797 |
| Landi 2019 (45) | Italy A | Observational trial | NSCLC | >1 | Nivolumab (n=419) | – | 327 | 1261 |
| Landi 2019 (45) | Italy B | Observational trial | NSCLC | >1 | Nivolumab (n=420) | – | 63 | 308 |
| Tomoya 2017( 49 ) | Korea | Observational trial | NSCLC | >1 | Nivolumab/Pembrolizumab (n=424) | – | 10 | 59 |
| Lee 2021( 50 ) | Korea | Observational trial | SCLC | 1 | Atezolizumab+CT (n=425) | – | 28 | 68 |
LM, liver metastases; CT, chemotherapy; NSCLC, non-small-cell lung cancer; SCLC, small-cell lung cancer; Blue indicates RCTs, while gray indicates Observational trials.