Table 1.
Main characteristics of the 17 studies qualified to be included in this meta-analysis.
| Author, year | Country | Cancer type | Stage | Immunotherapeutic agent (1=PD-1, 2=CTLA4, 3 PDL-1) |
Sample size | Agea | MDSC type | MDSC marker | Cutoff method | Cutoff value | Outcome | Data availability |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gaißler 2023 (31); | Germany | Melanoma | IV | (1)Pembrolizumab, (1) Nivolumab single or + (2) Ipilimumab |
141 | 64 | M-MDSC | M-MDSC: Lin- CD11b+/CD14+/CD33+/HLA Drlow | other ‡ | 18,1% (%total mononuclear leucocytes) | PFS, OS | extracted paper |
| Tomela, 2023 (29); | Poland | Melanoma | III-IV | (1)Nivolumab, (1)Pembrolizumab |
46 | 63 (32–92) | total MDSC M-MDSC PMN-MDSC |
MDSC: CD11b+/HLA-DR−/low/CD33+, M-MDSC: CD14+/CD33high/CD11b+/HLA-DR−/low and PMN-MDSC: CD66b+/CD33dim/CD11b+/HLA-DR−/low |
Median | 7.1%(total), 3% (PMN-MDSC), 4.1% (M-MDSC) (%alive PBMC) |
PFS | calculated |
| Petrova, 2023 (30); | Germany | Melanoma | III-IV | (1)Pembrolizumab, (1)Nivolumab single or + (3)Ipilimumab |
29 | 64(41–84), | M-MDSC, PMN-MDSC |
M-MDSC: HLA-DRlow/−CD33highCD14+ PMN-MDSC: HLA-DRlow/−CD33dimCD66b+Lin−; |
Median | 0.54% (PMN-MDSC) 0.73% (M-MDSC) (%alive PBMC) |
PFS, OS | Extracted paper♦ |
| Girardi, 2022 (32); | USA | Urothelian carcinoma | IV | (1)Nivolumab+Cabozantinib | 30 | 64.5 (47–80) | M-MDSC PMN-MDSC |
M-MDSC: CD14+ CD11b+ HLA–DRlow/– CD15–. PMN-MDSC: CD14− CD11b+ CD15+; |
Median | NR | PFS, OS | calculated |
| Bronte, 2022 (33); | Italy | NSCLC | III-IV | (1)Pembrolizumab, (1)Nivolumab (3)Atezolizumab, Combination |
22 | 70.1 (64.8–75.0) | M-MDSC | M-MDSC: CD14 + HLA-DR − /lowCD11b + CD33 + | Median | 1.9% (%CD45+) | PFS, OS | extracted paper |
| Araujo, 2021 (35); | Denmark | Solid tumor | mixed | mixed (1,2,3) | 33 | 60 (36 -75) | M-MDSC | M-MDSC: CD14+ CD3- CD19- HLA-DR low, CD56- | Median | NR (% alive PBMC) | PFS, OS | extracted paper |
| Krebs, 2021 (34); | Germany | Melanoma | III-IV | (2)Ipilimumab (1,2)Ipilimumab/Nivolumab (1)Pembrolizumab, (1)Nivolumab |
45 | 70 (27–86) | PMN-MDSC | PMN-MDSC: CD15+CD33+; | Median | 0.5% (% alive PBMC) | OS | Calculated |
| de Coaña, 2020 (37); | Sweden | Melanoma | IV | (1)Nivolumab, (1)Pembrolizumab |
36 | 68.5 (37–83) | M-MDSC PMN-MDSC | M-MDSC: CD14+HLA-DRlow/-; PMN-MDSC: NR |
cutoff finder software | 0.09% (PMN-MDSC), 10.70% (M-MDSC), (% alive PBMC) |
OS, | extracted paper |
| Koh, 2020 (39); |
Korea | NSCLC | I-IV | (1)Nivolumab, (1)Pembrolizumab |
132 | 62 (34–88) | M-MDSC PMN-MDSC |
PMN-MDSC: Lin− CD15+ CD14− CD11b+ HLA-DR−/low; M-MDSC: Lin− CD15− CD14+ HLA-DR−/low |
Median | NR | PFS, OS | extracted paper |
| Passaro et al., 2020 (38); | Italy | NSCLC | III-IV | (1)Nivolumab | 53 | 64 (56–70) | PMN-MDSC | PMN-MDSC: SSClow Lin−/HLA-DR−/lowCD33+/CD13+/CD11b+/CD15+/CD14− | other | 6 cell/μL | PFS, OS | extracted paper |
| Karzai, 2018 (40), | USA | Prostate Cancer | IV | (1)durvalumab + olaparib | 17 | 66 (45–79) | MDSC | MDSC: CD3+−CD19−CD56−HLA-DR− CD11b+CD33+ | Median | 1.26% (% total viable cells) | PFS | calculated |
| de Coaña, 2017 (36); | Sweden | Melanoma | IV | (2)Ipilimumab | 43 | (23–80) | M-MDSC, PMN-MDSC |
PMN-MDSC: Lin-CD14- CD11b+ CD33+ CD15+ HLA-DRlo/neg; M-MDSC: CD14+ HLA-DRlo/neg |
cutoff finder software | 2.3%(PMN-MDSC); 18.6% (M-MDSC), (% alive PBMC) |
OS | extracted paper |
| Sade-Feldman, 2016 (42); | Israel | Melanoma | IV | (2)Ipilimumab | 56 | 60.7 | MDSC | MDSC: CD33+CD11b+HLA-DR- | Data distribution | 55.5% (as the CD33+CD11b+ (%) of gated HLA-DR− cells) | OS | calculated |
| Weber, 2016 (41); | USA | Melanoma | III-IV | (1)Nivolumab | 92 | 60 | M-MDSC | M-MDSC: Lin-CD11b+/CD14+/HLA Drlow | Median | 12.6% (%alive PBMC) | OS | calculated |
| Martens, 2016 (43); | Europe (multicentral) | Melanoma | IV | (2)Ipilimumab | 209 (MDSC measured n=164) |
58 | M-MDSC | MDSC: Lin−CD14+HLA-DR+−/niedrig | Other | 5.1% (NR) | OS | extracted paper |
| Santegoets, 2014 (44); | Netherlands | Prostate Cancer | IV | (2) Ipilimumab + GVAX | 28 | NR | M-MDSC | M-MDSC: Lin- CD14+ HLA-DR-/low, | Cox regression | 0.3% (NR) | OS | extracted paper |
| Kitano, 2014 (45); | USA | Melanoma | III-IV | (2)Ipilimumab | 68 | 62 (34–83) | M–MDSC | M-MDSC: Lin- CD14+CD11b+ HLA-DRlow/- | Log-Rank-Statistic | 14.9% (%HLA-DR low/− in Lin-CD14+CD11b+) | OS | extracted paper |
United states of America (USA); non-small cell lung cancer (NSCLC); GVAX vaccine; myeloid-derived suppressor cells (MDSC); monocytic MDSC (M-MDSC); polymorphonuclear (PMN-MDSC); Peripheral blood mononuclear cells (PBMC); Programmed Cell Death Protein 1 (PD-1), Programmed cell death ligand-1 (PD-L1), cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4), not reported (NR).