398PD - PD-L1 status in Taiwanese lung adenocarcinoma patients: Comparison of PD-L1 immunohistochemical assays using antibody clones 22C3, SP142 and SP263...

Date 19 December 2016
Event ESMO Asia 2016 Congress
Session Immunotherapy of cancer
Topics Cancer Immunology and Immunotherapy
Lung and other Thoracic Tumours
Presenter YI-CHEN Yeh
Citation Annals of Oncology (2016) 27 (suppl_9): ix123-ix125. 10.1093/annonc/mdw588
Authors Y. Yeh1, S. Lin2, C. Chiu3, Y. Wu4, W. Hsieh1, H. Ho1, T. Chou1
  • 1Department Of Pathology And Laboratory Medicine, Taipei Veterans General Hospital, 11217 - Taipei/TW
  • 2Department Of Pathology, Taipei Hospital, Ministry of Health and Welfare, 242-13 - Taipei/TW
  • 3Department Of Chest Medicine, Taipei Veterans General Hospital, 11217 - Taipei/TW
  • 4Department Of Surgery, Division Of Thoracic Surgery, Taipei Veterans General Hospital, 11217 - Taipei/TW

Abstract

Background

In non-small cell lung cancer, immune checkpoint blockade of PD-1 axis had shown promising treatment results. There are at least four different PD-1 axis blocking agents and each was accompanied by its own PD-L1 IHC assay as a biomarker test. Data are still limited regarding the comparison between different assays. The aim of this study is to compare the staining characteristics of different PD-L1 IHC assays and correlate the results with clinical, pathological and molecular features in a large cohort of lung adenocarcinoma patients in Taiwan.

Methods

This study used a tissue microarray constructed with tumor tissue from 219 lung adenocarcinoma patients who underwent surgical resection in Taipei Veterans General Hospital. Three different PD-L1 IHC assays were performed: Dako 22C3 pharmDx on Dako autostainer, SP142 (Spring Bioscience) on Leica autostainer, SP263 (Ventana) on Ventana autostainer. Positive PD-L1 expression was defined as membranous staining in ≥ 1% of tumor cells; negative PD-L1 expression was defined as membranous staining in 

Results

PD-L1 positive rates were 16.9%, 15.5% and 40.6% with 22C3, SP142 and SP263, respectively. PD-L1 expression was concordant in 158 patients (72.1%), among whom 129 (58.9%) were PD-L1 negative, and 29 (13.2%) were PD-L1 positive with all assays. There was a high concordance between 22C3 and SP142 (94%). SP263 showed lower concordance with the other two assays (76.3% and 74% concordance with 22C3 and SP142, respectively). In all assays, solid histology was associated with higher rate of PD-L1 positivity (P 

Conclusions

PD-L1 IHC assays with 22C3 and SP142 showed high concordance, but SP263 assay showed substantial higher rate of PD-L1 positivity. The associations between PD-L1 expression and clinicopathological features, including tumor histology, EGFR mutation and survival, were consistent across different PD-L1 IHC assays.

Clinical trial indentification

Legal entity responsible for the study

Taipei Veterans General Hospital

Funding

Taipei Veterans General Hospital

Disclosure

All authors have declared no conflicts of interest.