Table 3.
PD-L1 Expression in Metaplastic Breast Cancer
| Ref | Year | Cohort | PD-L1 Antibody Clone | Staining Criteria | % Cases with Positive PD-L1 Expression |
|---|---|---|---|---|---|
| Mittendorf et al59 | 2014 | 120 TNBC | 5H1 | Memb. staining in >5% tumor cells | 19% tum |
| Joneja et al53 | 2016 | 297 TNBC (75 MpBC) | SP142 | Tumor with ≥2+ intensity in ≥5% of the tumor cells | MpBC 46% tum; 9% TNBC tum |
| Beckers et al60 | 2016 | 161 TNBC | E1L3N | ≥ 1% tum memb. or cyto. and ≥1% immune cells in the stromal compartment | 64% tum memb., 80% cyto. and 93% stromal compartment |
| Dogukan et al61 | 2019 | 61 TNBC (incl 6 MpBC) | E1L3N | Memb. or cyto. staining in ≥1% tumor cells; ≥5% staining in peri-tumoral regions | 38% tumor cell; 48% tumor immune microenvironment |
| Morgan et al62 | 2020 | 146 TNBC (27 MpBC) | SP263 | Memb. staining in ≥1% of tumor cells; immune cells | MpBC 30% tum, 73% immune; TNBC 10% tum, 59% immune |
| Afkhani et al49 | 2019 | 14 MpBC | SP263 | >1+ intensity in >1% immune cells | 50% immune cells |
| Lien et al63 | 2020 | 82 MpBC | SP142 | % tumor cells; immune cells as % of tumor area | 17% tum; 48% immune cell |
| Kalaw et al64 | 2020 | 125 MpBC | E1L3N | ≥5% tumor/immune cells displaying cyto. or memb. staining | 73% tum, 69% stromal TILS |
| Chao et al65 | 2020 | 60 MpBC | E1L3N | ≥ 1% memb. or cyto. Staining | 50% tum, 60% TILs |
Abbreviations: BC, breast cancer; ER, estrogen receptor; IBC-NST, invasive breast cancer-no special type; MpBC, metaplastic breast cancer; NACT, neo-adjuvant chemotherapy; PR, progesterone receptor; TILs, tumour infiltrating lymphocytes; TNBC, triple-negative breast cancer; Cyto, cytoplasmic; memb., membraneous; tum, tumour.