PCR-based analysis of PD-L1 RNA expression in lung cancer: comparison with commonly used immunohistochemical assays.

Autor: Venina AR; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Ivantsov AO; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Iyevleva AG; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia. Electronic address: aglayai@inbox.ru., Kuligina ES; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Preobrazhenskaya EV; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Yurlov DO; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Rawlinson KE; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Kosmin AV; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia., Savelov NA; Moscow City Oncological Hospital №62, Moscow 143423, Russia., Raskin GA; S. Berezin International Institute of Biological Systems, Saint-Petersburg 197758, Russia., Imyanitov EN; N.N. Petrov Institute of Oncology, St.-Petersburg 197758, Russia; St.-Petersburg Pediatric Medical University, St.-Petersburg 194100, Russia; I.I. Mechnikov North-Western Medical University, St.-Petersburg 191015, Russia.
Jazyk: angličtina
Zdroj: Annals of diagnostic pathology [Ann Diagn Pathol] 2022 Aug; Vol. 59, pp. 151968. Date of Electronic Publication: 2022 May 06.
DOI: 10.1016/j.anndiagpath.2022.151968
Abstrakt: Background: PD-L1 testing is currently performed by immunohistochemistry (IHC). We questioned whether the results of PCR-based measurement of PD-L1 RNA expression correlate with IHC scores obtained by different commercial assays.
Materials and Methods: 167 consecutive non-squamous non-small cell lung carcinomas (NSCLCs) were analyzed for PD-L1 RNA expression and 22C3, SP263, and SP142 IHC scoring using recommended cut-offs. RNA expression was divided into low, moderate, and high categories.
Results: RNA and protein expression demonstrated moderate correlation as continuous variables. Using prespecified RNA cut-offs, PCR testing showed a high negative predictive value towards the IHC analysis: the share of PD-L1 protein-negative tumors among cases classified as PD-L1-low by the PCR test reached 92-99% for all three antibodies. Meanwhile, about half of cases with moderate to high PD-L1 RNA expression had IHC staining in less than 1% tumor cells as determined by 22C3 or SP263 antibodies. Among the 51 discordant cases, which had <1% tumor staining by both 22C3 and SP263 clones but high RNA level, 29 (57%) showed ≥1% positive immune cells by SP263 and/or 22C3, 14 cases (27%) had detectable IHC expression in 0.1-0.9% tumor or immune cells by SP263 and/or 22C3, and 8 (16%) were entirely negative by IHC.
Conclusion: Some NSCLCs demonstrate readily detectable PD-L1 expression on the level of RNA, but fall below commonly accepted cut-offs by IHC. It remains to be studied whether these discrepancies are attributed to technical or biological reasons. Clinical sensitivity of these tumors to immune therapy deserves additional investigations.
(Copyright © 2022 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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