396O - The heterogeneity of PD-L1 expression among the different histological components and metastatic lymph nodes in patients with resected lung adenosq...

Date 19 November 2017
Event ESMO Asia 2017 Congress
Session Thoracic malignancies 2
Topics Immunotherapy
Thoracic malignancies
Translational Research
Basic Principles in the Management and Treatment (of cancer)
Therapy
Presenter Yiwei Liu
Citation Annals of Oncology (2017) 28 (suppl_10): x119-x121. 10.1093/annonc/mdx669
Authors Y. Liu, S. Ren, P. Yingying, C. Wu, Z. Dong, F. Wu, Q. Tian, Y. Pan, C. Zhou
  • Department Of Oncology, Shanghai Pulmonary Hospital, Tongji University, 200433 - Shanghai/CN

Abstract

Background

Programmed cell death ligand 1 (PD-L1) expression by immunohistochemistry (IHC) is a predictive factor for anti–PD-1/PD-L1 monoantibodies. However, intertumoral heterogeneity of PD-L1 expression and its accordance between resected tissue and biopsy tissue or cytological tumor samples remains controversial.

Methods

A total of 72 patients who consecutively undergone primary lung cancer resection and were diagnosed as pulmonary adenosquamous carcinoma were included. PD-L1 expression level was assessed by IHC (PD-L1: Clone E1L3N; Cell Signaling #13684) in different histological component of both primary and lymph node tissues respectively.

Results

With a 5% of cutoff, PD-L1 expression was 20.8%, 33.3% in adenomatous and squamous cell component respectively. When various cutoffs including 0.01, 0.05, 0.10 were used, the PD-L1 expression was discrepant in 26.4%, 19.4%, 12.5% cases respectively. With combination of the expression in tumor cells (TC) and tumor-infiltrated lymphocytes (TILs), discrepancies between two histological components were observed in 13.9%, 22.2%, 30.6% cases repectively. Of 38 lymphatic metastasis cases, there were 4 types of lymphatic node histology including adenocarcinoma, squamous cell, adenosquamous and a mixture of above. By different histological component and cutoff value, the concordances of PD-L1 expression were in 74.1%, 80.0%, 88.9% cases for adenomatous cell component and 90.0%, 80.0%, 85.0% cases for squamous cell component respectively. In addition, the discrepancy of adenocarcinoma histological subtype accounts for the lower concordant rate in adenomatous component.

Conclusions

PD-L1 expression showed a high discrepancy among adenomatous component and squamous cell components. In contrast, PD-L1 was highly consistent between paired histological types of lymph node and the primary lesion, which may suggest that the intrinsic genomic features plays important role in the PDL1 heterogeneously expression.

Clinical trial identification

Legal entity responsible for the study

Tongji Pulmonary Hospital, Tongji University

Funding

Shanghai Municipal Education Commission

Disclosure

All authors have declared no conflicts of interest.Table 1.1: 396O

PD-L1 difference between adenomatous and squamous components

cutoff valuePD-L1 expression in TC in primary tumor site
concordance (%)adenomatous component PD-L1+ n (%)squamous cell component PD-L1+ n(%)kappa
0.0173.632 (44.4)39 (54.2)0.477
0.0580.615 (20.8)24 (33.3)0.527
0.1087.56 (8.3)11 (15.3)0.407
Table 1.2: 396O

PD-L1 heterogeneity between adenomatous and squamous components based on tumor cells and TILs

cutoff valuePD-L1 expression in TC and TILs in primary tumor site
concordance (%)adenomatous component PD-L1+ n(%)squamous cell component PD-L1+ n(%)kappa
0.0169.447(65.3)45(62.5)0.338
0.0577.820(27.8)26(36.1)0.493
0.1086.17(9.7)11 (15.3)0.370
Table 1.3: 396O

PD-L1 difference in TC between primary tumor site and lymphatic metastasis

cut off valueadenomatous component n = 27squamous cell component n = 20
concordanceprimary tumor PD-L1+ n(%)nodal metastasis PD-L1+ n (%)kappaconcordanceprimary tumor PD-L1+ n(%)nodal metastasis PD-L1+ n (%)kappa
0.0177.814 (51.9)12 (44.4)0.55790.012 (60.0)12 (60.0)0.792
0.0574.19 (33.3)6 (22.2)0.36480.09 (45.0)9 (45.0)0.596
0.1088.94 (14.8)3 (11.1)0.50985.05 (25.0)4 (20.0)0.571