13P Comparison study of different programmed death-ligand 1 (PD-L1) assays, readers and scoring methods in triple-negative breast cancer (TNBC)

2021

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

2020

Abstract Background 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. Methods Thirty archival TNBC tissue specimens were selected from a set of 107 based on PD-L1 IC expression per VENTANA SP142 ( 5%: 8 cases), to represent the distribution of PD-L1 IC–positivity in the pivotal atezolizumab studies (Emens et al., SABCS 2018; JAMA Oncol 2019). Serial histologic sections were stained with VENTANA SP142 and SP263, and DAKO 22C3 and…

A multicentre analytical comparison study of inter-reader and inter-assay agreement of four programmed death-ligand 1 immunohistochemistry assays for…

2020

AIMS Studies in various cancer types have demonstrated discordance between results from different programmed death-ligand 1 (PD-L1) assays. Here, we compare the reproducibility and analytical concordance of four clinically developed assays for assessing PD-L1-positivity in tumour-infiltrating immune cells in the tumour area (PD-L1-IC-positivity) in triple-negative breast cancer (TNBC). METHODS AND RESULTS Primary TNBC resection specimens (n = 30) were selected based on their PD-L1-IC-positivity per VENTANA SP142 ( 5%: eight cases). Serial histological sections were stained for PD-L1 using VENTANA SP142, VENTANA SP263, DAKO 22C3 and DAKO 28-8. PD-L1-IC-positivity and tumour cell expression (…

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

2019

Abstract Background 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. Methods Thirty archival TNBC tissue specimens were selected from a set of 107 based on PD-L1 IC expression per VENTANA SP142 ( 5%: 8 cases), to represent the distribution of PD-L1 IC–positivity in the pivotal atezolizumab studies (Emens et al., SABCS 2018; JAMA Oncol 2019). Serial histologic sections were stained with VENTANA SP142 and SP263, and DAKO 22C3 and…

Interassay and interobserver comparability study of four programmed death-ligand 1 (PD-L1) immunohistochemistry assays in triple-negative breast canc…

2021

Different immunohistochemical programmed death-ligand 1 (PD-L1) assays and scorings have been reported to yield variable results in triple-negative breast cancer (TNBC). We compared the analytical concordance and reproducibility of four clinically relevant PD-L1 assays assessing immune cell (IC) score, tumor proportion score (TPS), and combined positive score (CPS) in TNBC. Primary TNBC resection specimens (n = 104) were stained for PD-L1 using VENTANA SP142, VENTANA SP263, DAKO 22C3, and DAKO 28–8. PD-L1 expression was scored according to guidelines on virtual whole slide images by four trained readers. The mean PD-L1 positivity at IC-score ≥1% and CPS ≥1 ranged between 53% and 75% with th…