Table 9 Summary of recent published studies of PD-L1 expression in breast cancer using FDA-approved clones
Reference | No., type of breast tumors | Clones | Pathologic material | Cutoffs for positive/high staining | Correlation with prognosis |
|---|---|---|---|---|---|
He et al. [16] | 68, IBC, post NACT | 28–8 | TMA | TC > 1% | Worse prognosis |
Humphries et al. [17] | ≥ 109, various types | SP142 | TMA | > 1%, epithelial and lymphoid cells | Better prognosis |
Karnik et al. [18] | 136, ductal (primary and metastasis) | 22C3, SP263 | WSS (biopsies and resections) | TC ≥ 1% | Not performed |
Li et al. [19] | 191, HER2 positive, no NACT | 22C3, 28–8 | TMA | TC ≥ 1%; IC, cutoff not defined | Better prognosis |
Pelekanou et al. [20] | 163, HER2 negative, locally advanced, or IBC (120, pretreatment; 43, post NACT) | 22C3 | WSS | Either tumor or stromal cells ≥ 1% | Not associated (but better pCR) |
Downes et al. [21] | 30, not specified | 22C3, SP142, SP263 | TMA | 22C3: CPS ≥ 1; SP142: IC ≥ 1%; SP263: cutoff not defined | Not performed |
Noske et al. [22] | 1318, various types, all node-positive | SP263 | TMA | TC ≥ 1%; IC ≥ 1% | Not associated |
Van Berckelaer et al. [23] | 349 (207, pretreatment IBC; 142, non-IBC) | SP142 | WSS (biopsies) | TC, IC (categorized based on %) | Not associated (but better pCR) |