TY - JOUR
T1 - Determinants of variability of five programmed death ligand-1 immunohistochemistry assays in non-small cell lung cancer samples
AU - Soo, Ross A.
AU - Lim, Joey Sze Yun
AU - Asuncion, Bernadette Reyna
AU - Fazreen, Zul
AU - Herrera, Maria Cynthia
AU - Omar, Mohd Feroz Mohd
AU - Phuong, Nguyen Hoang Diem
AU - Seet, Ju Ee
AU - Amanuel, Benhur
AU - Iacopetta, Barry
AU - Byrne, David
AU - Hendry, Shona
AU - Fox, Stephen
AU - Soong, Richie
PY - 2018/1/1
Y1 - 2018/1/1
N2 - 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. PDL1 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 ranking of cases across IHC protocols could be observed, albeit with different quanta and limits of detection. Single-slide OPAL 7-color fluorescence IHC analysis revealed a high degree of co-localization of staining from the 5 PD-L1 antibodies. Using SP142 antibody in a BOND-MAX protocol led to increased TC% quanta, while retaining a similar ranking of samples according to TC%. The results of this study highlight tumor PD-L1 status can vary significantly according to IHC protocol. Protocoldependent staining intensities and nominated thresholds for positivity contribute to this variability, while the antibody used appears to be less of a factor.
AB - 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. PDL1 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 ranking of cases across IHC protocols could be observed, albeit with different quanta and limits of detection. Single-slide OPAL 7-color fluorescence IHC analysis revealed a high degree of co-localization of staining from the 5 PD-L1 antibodies. Using SP142 antibody in a BOND-MAX protocol led to increased TC% quanta, while retaining a similar ranking of samples according to TC%. The results of this study highlight tumor PD-L1 status can vary significantly according to IHC protocol. Protocoldependent staining intensities and nominated thresholds for positivity contribute to this variability, while the antibody used appears to be less of a factor.
KW - Immunohistochemistry
KW - Immunotherapy
KW - Non-small cell lung cancer
KW - Programmed death ligand-1
UR - http://www.scopus.com/inward/record.url?scp=85040931856&partnerID=8YFLogxK
U2 - 10.18632/oncotarget.23827
DO - 10.18632/oncotarget.23827
M3 - Article
C2 - 29467933
AN - SCOPUS:85040931856
VL - 9
SP - 6841
EP - 6851
JO - Oncotarget
JF - Oncotarget
SN - 1949-2553
IS - 6
ER -