Comparison of PD-L1 IHC evaluations
| Reference | Type of specimen | PD-L1 clone | Method | Cut-off | Membranous/cytoplasmic staining | Positive cases (%) |
|---|---|---|---|---|---|---|
| Konishi et al.43 | Resectiona | M1H1 (homemade) | Manual | 11% (median percentage of tumor cells expressing PD-L1) | Membranous and/or cytoplasmic staining of tumor cells | 26 (50.0) |
| Mu et al.45 | Resectiona | N/A | Manual | Median value of all semiquantitative H-scores | Membranous and/or cytoplasmic staining of tumor cells | 58 (53.2) |
| Chen et al.38 | Resectionb | Clone 236A/E7 polyclonal (Abcam) | Manual | IRS≥3e | Membranous and/or cytoplasmic staining of tumor cells | 69 (57.5) |
| Chen et al.39 | Resction or CT-guided biopsya | Rabbit polyclonal (Abcam) | Manual | IRS≥3e | Membranous and/or cytoplasmic staining of tumor cells (expression on tumor associated macrophages was separately evaluated) | 136 (65.3) |
| Velcheti et al.46 | Tissue microarraya | 5H1 (Yale) | AQUA | PD-L1 protein cutoff for expression in our study was defined as the AQUA score of first signal detection beyond the signal intensity in FFPE samples from normal lung and negative controls | Membranous staining on tumor cells | Greece: 75 (24.9), US: 56 (36.1) |
| D’Incecco et al.41 | N/Aa | Ab58810 (Abcam) | Manual | Staining intensity with score 2 or more in ≥5% tumor cells | Not reported | 68 (55.3) |
| Azuma et al.35 | Resectiona | Rabbit polyclonal (Lifespan Biosciences) | Ventana automated system | No cut-off: H-score was appliedd | Membranous and/or cytoplasmic staining of tumor cells | 82 (50) |
| Mao et al.44 | Resectionb | Clone 2H11 (no vender available) | Manual | IRS≥2 | Membranous and/or cytoplasmic staining of tumor cells | 96 (72.7) |
| Tang et al.18 | N/Ac | PD-L1 E1L3N (CST) | Manual | ≥5% (regardless of intensity) | Membranous and/or cytoplasmic staining of tumor cells | 112 (65.9) |
| Cooper et al.40 | Resectiona | 22C3 (DAKO) | DAKO Automated system | ≥50% (regardless of intensity) | Membranous staining on tumor cells | 50 (7.4%): 5.1% in ADC, 8.1% on SCC, 12.1% |
| Boland et al.36 | Resectiona | Clone 5H1 | Manual | ≥1% (regardless of intensity) | Membranous and circumferential staining on tumor cells | 42 (19.6) |
| Kim et al.42 | Resectionb | PD-L1 E1L3N (CST) | Ventana automated system | IHC 2 (moderate) and 3 (strong) in >10% of tumor cells | Membranous staining on tumor cells | 89 (26.9) |
| Yang et al.47 | Resectionb | Mouse anti PD-L1/CD274 monoclonal (Proteintech Group) | Manual | ≥5% (regardless of intensity) | Membranous staining on tumor cells | 65 (39.9) |
| Zhang et al.21 | Resectionb | SAB2900365 (Sigma-Aldrich) | Manual | ≥8 (median quick score 0-18) | Membranous and/or cytoplasmic staining of tumor cells | 70 (49) |
| Koh et al.19 | Resectionb | PD-L1 E1L3N (CST) | Ventana automated system | IHC 2 (moderate) and 3 (strong) in >10% of tumor cells | Membranous and/or cytoplasmic staining of tumor cells | 293 (59) |
| Lin et al.20 | Resection or biopsya | ab58810 (Abcam) | Manual | Mean value of all semiquantitative H-scoresd | Membranous and/or cytoplasmic staining of tumor cells | 30 (53.6) |
| Calles et al.37 | N/Aa | Clone 9A11 (Gordon Freeman's laboratory, DFCI) | Manual | ≥5% (regardless of intensity) | Membranous staining on tumor cells | 27 (24) |
a: information regarding treatment prior procurement of the specimen is not available; b: no patients received any treatment prior procurement of the specimen; c: asubset of the patients received treatment prior procurement of the specimen; d: calculated by multiplying proportion of tumor cells with PD-L1 (0-3) by staining intensity score (0-3); e: calculated by multiplying staining intensity (0-3) x fraction of positive cells (0-3 based on % of positive tumor cells).