Reproducibility and concordance of 4 clinically developed programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) assays in triple negative breast cancer (TNBC)

Background null Atezolizumab (an anti–PD-L1 antibody) has shown clinical activity alone or in combination with nab-paclitaxel in patients (pts) with first-line metastatic TNBC who have PD-L1 expression on their tumour-infiltrating immune cells (IC). We analysed the performance of 4 PD-L1 IHC assays for PD-L1 IC expression in TNBC. null null null Methods null Thirty archival TNBC tissue specimens were selected from a set of 107 based on PD-L1 IC...