Table 4.
Summary of most important biomarkers that were studied for mixed cohorts and assessed risk of bias per article.
| Biomarker | N of Studies | N of Patients | Median Patients per Study (IQR) | Response | PFS | OS | Quality Assessment |
|---|---|---|---|---|---|---|---|
| TMB | 5 | 861 | 91 (68–317) | TMB was associated with response in 4/5 studies, not associated in 1/5 studies. | TMB was associated with PFS in 1/2 studies, not associated in 1/2 studies. | TMB was associated with OS in 1/4 studies, not associated in 3/4 studies. | 2/5 high risk, 3/5 moderate, 0/5 low risk of bias |
| PD-L1 expression on tumor cells | 5 | 298 | 51 (1–84) | PD-L1 expression was associated with response in 2/3 studies, not associated in 1/3 studies. | PD-L1 expression was not associated with PFS in 1/1 studies. | PD-L1 was associated with OS in 1/4 studies, not associated with OS in 3/4 studies. | 2/5 high risk, 3/5 moderate, 0/5 low risk of bias |
| Circulating tumor cells | 3 | 190 | 82 (22–86) | CTCs were associated with response in 3/3 studies. | CTCs were associated with PFS in 3/3 studies. | CTCs were associated with OS in 2/2 studies. | 1/3 high risk, 2/3 moderate 0/3 low risk |
| LDH | 2 | 141 | 71 (N/A) | LDH was not associated with response in 1/1 studies. | LDH was associated with PFS in 1/2 studies. | LDH was associated with OS in 1-2 studies, not associated with OS in 1/2 studies. | 0/2 high risk, 2/2 moderate, 0/2 low risk of bias |
| Neoantigen load (NAL) | 2 | 423 | 212 (N/A) | NAL was associated with response in 1/2 studies, not associated in 1/2 studies. | NAL was associated with OS in 1/2 studies, not associated with OS in 1/2 studies. | 2/2 high risk, 0/2 moderate, 0/2 low risk of bias | |
| TILs in tumor tissue | 2 | 123 | 62 (N/A) | TILs were associated with response in 1/1 studies. | TILs were not associated with PFS in 1/1 studies. | TILs were associated with OS in 2/2 studies. | 1/2 high risk 1/2 moderate, 0/1 low risk of bias |
| Gut microbiomes | 2 | 66 | 33 (N/A) | Gut microbiomes were associated with response in 2/2 studies. | 0/2 high risk, 2/2 moderate, 0/2 low risk | ||
| NLR | 1 | 32 | N/A | NLR was not associated with response in 1/1 studies. | 1/1 high risk, 0/1 moderate 0/1 low risk of bias | ||
| Tregs in tumor tissue | 1 | 32 | N/A | Tregs were not associated with OS in 1/1 studies. | 1/1 high risk, 0/1 moderate 0/1 low risk of bias |
Abbreviations: IQR: interquartile range, LDH: lactate dehydrogenase, NLR: neutrophil-to-lymphocyte ratio, TILs: tumor-infiltrating lymphocytes, TMB: tumor mutation burden, Tregs: regulatory T cells.