EP16.01-029 Inter-tumor Heterogeneity of PD-L1 Expression in Non-small Cell Lung Cancer

Abstract

The Dako PD-L1 immunohistochemistry (IHC) 22C3 pharmDx was approved by the US Food and Drug Administration, as a companion diagnostic test for pembrolizumab (Keytruda, Merk, Kenilworth, NJ, USA) in non-small cell lung cancer (NSCLC). Although increased PD-L1 expression levels can be associated with greater therapeutic efficacy of pembrolizumab, little is known about which tissue (primary or metastatic lesion) should be stained by 22C3 antibody. In this study, we investigated the concordant rate of PD-L1 expression between primary and metastatic lymph node.