Comparison of PD-L1 mRNA Expression Measured with the CheckPoint Typer® Assay with PD-L1 Protein Expression Assessed with Immunohistochemistry in Non-small Cell Lung Cancer

Erber R, Stoehr R, Herlein S, Giedl C, Rieker R, Fuchs F, Ficker JH, Hartmann A, Veltrup E, Wirtz RM, Brueckl WM (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Anticancer Research International Institute of Anticancer Research (IIAR)

Book Volume: 37

Pages Range: 6771-6778

Journal Issue: 12

DOI: 10.21873/anticanres.12137

Abstract

Immunohistochemical (IHC) assessment of programmed death-ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC) has become important since the development of anti-PD-1/-PD-L1 directed drugs. Various PD-L1 antibodies and cut-offs have been used in different trials to predict response to these drugs, thus comparison of those studies is difficult. We compared PD-L1 mRNA expression measured by RT-qPCR with PD-L1 protein expression evaluated by IHC. Moreover, we investigated the impact of different tumour tissue acquisition methods on the reliability of PD-L1 measurement techniques.NSCLC cases (N=22), including n=9 mediastinal lymph node biopsies acquired by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and n=5 metastases, were evaluated prospectively for PD-L1 protein on tumor cells (TC) and immune cells (IC) using E1L3N and 28-8 antibodies and PD-L1 mRNA using the CheckPoint TYPER® assay.In primary NSCLC tissues, agreement between PD-L1 mRNA and TC staining using the 28-8 antibody was excellent (?=0.85, p=0.0002). Comparing both PD-L1 antibodies against each other showed a kappa value of 0.58 (p=0.0106). In EBUS-TBNA, PD-L1 mRNA correlated perfectly with the 28-8 antibody (?=1.0, p=0.0023). PD-L1 mRNA levels significantly differed when comparing 28-8 TC staining of tumours >49% with 1-49% and 0% (p=0.0040; p=0.0081, respectively). In metastatic lesions, differences between PD-L1 mRNA and IHC became apparent (?=0.2, p=0.2525).Testing of PD-L1 mRNA and 28-8 IHC showed an excellent agreement in NSCLC samples including mediastinal lymph node biopsies. Since PD-L1 expression in >50% TC detected by 28-8 IHC can be reliably detected by RT-qPCR, quantitative PD-L1 mRNA determination should be considered as an alternative to IHC as there is no interobserver variability in RNA results.

Authors with CRIS profile

Ramona Erber Institute of Pathology Ralf Rieker Institute of Pathology Arndt Hartmann Lehrstuhl für Allgemeine Pathologie und Pathologische Anatomie

Involved external institutions

Paracelsus Medizinische Privatuniversität, Nürnberg DE Germany (DE) STRATIFYER Molecular Pathology GmbH DE Germany (DE)

How to cite

APA:

Erber, R., Stoehr, R., Herlein, S., Giedl, C., Rieker, R., Fuchs, F.,... Brueckl, W.M. (2017). Comparison of PD-L1 mRNA Expression Measured with the CheckPoint Typer® Assay with PD-L1 Protein Expression Assessed with Immunohistochemistry in Non-small Cell Lung Cancer. Anticancer Research, 37(12), 6771-6778. https://doi.org/10.21873/anticanres.12137

MLA:

Erber, Ramona, et al. "Comparison of PD-L1 mRNA Expression Measured with the CheckPoint Typer® Assay with PD-L1 Protein Expression Assessed with Immunohistochemistry in Non-small Cell Lung Cancer." Anticancer Research 37.12 (2017): 6771-6778.

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