@article{JTD34565,
author = {Yuichi Saito and Sho Horiuchi and Hiroaki Morooka and Takayuki Ibi and Nobumasa Takahashi and Tomohiko Ikeya and Yoshihiko Shimizu and Eishin Hoshi},
title = {Inter-tumor heterogeneity of PD-L1 expression in non-small cell lung cancer},
journal = {Journal of Thoracic Disease},
volume = {11},
number = {12},
year = {2019},
keywords = {},
abstract = {Background: The Dako PD-L1 immunohistochemistry (IHC) 22C3 pharmDx and the Dako 28-8 IHC pharmDx assays were approved by the US Food and Drug Administration, as a companion diagnostic test for pembrolizumab (Keytruda, Merk, Kenilworth, NJ, USA) and a complementary diagnostic test for nivolumab (Opdivo, Bristol Meyer Squibb, New York, NY, USA) in non-small cell lung cancer (NSCLC), respectively. Increased PD-L1 expression levels can be associated with greater therapeutic efficacy of pembrolizumab relative to other anti-PD-1 agents. However, in treatment decision making, little is known about which tissue (primary or metastatic lesion) should be stained by 22C3 antibody. We investigated the relationship between PD-L1 expression in primary tumors and paired metastatic lymph nodes using the 22C3 assay, and evaluated the concordance between the 22C3 and 28-8 assays.
Methods: PD-L1 expression was evaluated in cells from primary tumors and paired metastatic lymph nodes using the 22C3 and 28-8 IHC assays. Total 35 patients with primary tumor and paired metastatic lymph node were enrolled into this study, and all samples were surgically resected, formalin-fixed, and paraffinembedded NSCLC tissues. Tumor cells exhibiting complete or partial membrane staining, were considered as PD-L1 positive. On the basis of tumor proportion score (TPS), all samples were classified as no expression (TPS: },
issn = {2077-6624}, url = {https://jtd.amegroups.org/article/view/34565}
}