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 Immunotherapy
Thoracic malignancies
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.