Interobserver Reliability of Programmed Cell Death Ligand-1 Scoring Using the VENTANA PD-L1 (SP263) Assay in NSCLC

Gareth H. Williams*, Andrew G. Nicholson, David R.J. Snead, Erik Thunnissen, Sylvie Lantuejoul, Paul Cane, Keith M. Kerr, Marco Loddo, Marietta L.J. Scott, Paul W. Scorer, Craig Barker

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Introduction: The VENTANA PD-L1 (SP263) Assay is approved for use with anti–programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) therapies in NSCLC and urothelial carcinoma. Here, we investigate interobserver reliability of the SP263 assay, applied to PD-L1 scoring of tumor cells (TCs) in NSCLC. Methods: Six practicing European pulmonary pathologists independently scored the proportion of TCs expressing PD-L1 (TC score) from 200 archival, commercially sourced, formalin-fixed paraffin-embedded NSCLC resections stained using the SP263 assay. Agreement in scores was analyzed using the intraclass correlation coefficient and concordance in patient's classification using Fleiss’ kappa. Results: Results from 172 samples showed strong pair-wise correlations between pathologists (R2 >0.89) for TC scoring with an intraclass correlation coefficient of 0.96. Overall agreement was greater than 90% for TC of 1% and above, and greater than 94% for TCs of at least 25% and at least 50%. Fleiss’ kappa showed substantial agreement for TC of 1% and above, and almost perfect agreement for TCs of at least 25% and at least 50%. Conclusions: Assessment of TC score in NSCLC was highly reproducible using the SP263 assay, building confidence in the accuracy of this assay in selection of patients for anti–PD-1/PD-L1 therapy.

Original languageEnglish
Number of pages6
JournalJournal of Thoracic Oncology
Volume15
Issue number4
DOIs
Publication statusE-pub ahead of print - 1 Jan 2020

Cite this

Williams, G. H., Nicholson, A. G., Snead, D. R. J., Thunnissen, E., Lantuejoul, S., Cane, P., ... Barker, C. (2020). Interobserver Reliability of Programmed Cell Death Ligand-1 Scoring Using the VENTANA PD-L1 (SP263) Assay in NSCLC. Journal of Thoracic Oncology, 15(4). https://doi.org/10.1016/j.jtho.2019.11.010