Determinants of variability of five programmed death ligand-1 immunohistochemistry assays in non-small cell lung cancer samples.

Determinants of variability of five programmed death ligand-1 immunohistochemistry assays in non-small cell lung cancer samples. Oncotarget. 2018 Jan 23;9(6):6841-6851 Authors: Soo RA, Yun Lim JS, Asuncion BR, Fazreen Z, Herrera MC, Mohd Omar MF, Diem Phuong NH, Seet JE, Amanuel B, Iacopetta B, Byrne D, Hendry S, Fox S, Soong R Abstract Programmed death ligand-1 (PD-L1) expression as determined by immunohistochemistry (IHC) is potentially predictive of clinical outcome. The aim of this study was to assess the concordance of reported PD-L1 IHC assays and investigate factors influencing variability. Consecutive sections from 20 non-small cell lung cancers (NSCLCs) comprising resection, core biopsy, cytology and pleural fluid samples underwent IHC with 5 different antibody/autostainer combinations: 22C3/Link48, 28-8/BOND-MAX, E1L3N/BOND-MAX, SP142/BenchMark and SP263/BenchMark. PD-L1 RNA levels were assessed using RNAscope. The frequency of positive cases using scoring thresholds from clinical trials was 72%, 33%, 61%, 56%, and 33% for the 5 IHC protocols respectively, and 33% for RNAscope. Pairwise agreement on the classification of cases as positive or negative for PD-L1 expression ranged from 61%-94%. On a continuous scale, the lowest correlation was between 28-8/BOND-MAX and SP142/BenchMark (R2=0.25) and highest was between 22C3/Link48 and E1L3N/BOND-MAX (R2=0.71). When cases were ordered according to tumor cell (TC)%, a similar ran...
Source: Oncotarget - Category: Cancer & Oncology Tags: Oncotarget Source Type: research