117P - Evaluation of tumor- and stromal immune marker heterogeneity in non-small cell lung cancer

Date 10 October 2016
Event ESMO 2016 Congress
Session Poster display
Topics Immunotherapy
Translational Research
Non-small-cell lung cancer
Basic Principles in the Management and Treatment (of cancer)
Therapy
Presenter David Casadevall Aguilar
Citation Annals of Oncology (2016) 27 (6): 15-42. 10.1093/annonc/mdw363
Authors D. Casadevall Aguilar1, L. Pijuan2, S. Clave2, A. Taus1, A. Hernández1, M. Lorenzo2, S. Mojal3, S. Menéndez2, J. Albanell4, M. Salido4, E. Arriola4
  • 1Medical Oncology, University Hospital del Mar, 08003 - Barcelona/ES
  • 2Pathology, University Hospital del Mar, 08003 - Barcelona/ES
  • 3Assessorament Metodològic En Investigació Biomèdica (amib), Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), 08003 - Barcelona/ES
  • 4Cancer Research Program, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), 08003 - Barcelona/ES

Abstract

Background

Immunotherapy is the current standard in second-line treatment for non-small cell lung cancer (NSCLC) patients. However, accurate identification of patients who benefit based on immune marker (IM) expression remains a challenge. Here, we aimed to estimate the potential impact of heterogeneity on the assessment of IM expression in both lung adenocarcinoma (ADC) and squamous-cell carcinoma (SCC).

Methods

A total of 144 surgically treated NSCLC patients were included, 94 ADCs and 50 SCCs. Two tumor cores per patient were incorporated into tissue microarrays (TMA). CD3 and CD8 were assessed by immunohistochemistry (IHC) and PD-L1 by IHC and FISH. Expression of IM was analyzed both in tumor cells (TC) and tumor stroma (TS). A PD-L1 positivity threshold of ≥1% was established for IHC and PDL1 gene amplification was defined as a PDL1/CEP9 ratio of ≥2. In each core, CD3 and CD8 positive cells were recorded quantitatively and the CD8/CD3 ratio was calculated. Heterogeneity of IM between corresponding tumor cores was analyzed using kappa agreement index. Finally, IM expression was correlated with clinical, pathological and molecular variables.

Results

Patients' median age was 65, 80% were male and 46% were current smokers. PD-L1 was expressed in TC and TS in 22% and 62% of cases, respectively. Amplification of PDL1 was found in 12 of cases, of which 8 (67%) were IHC PD-L1 positive in TC. Heterogeneity of TC PD-L1 positivity was 8% in ADC and 6% in SCC. Regarding TS PD-L1 expression, discordance between corresponding cores was found in 19% and 34% of ADC and SCC cases, respectively. PDL1 amplification was discordant between cores in 5 of 12 (42%) cases. Per core, median CD3 and CD8 positive cells were 436 and 159, respectively. Median CD8/CD3 ratio was 0.23 in ADC and 0.53 in SCC. Taking these values as cut-off points, CD8/CD3 ratio was discordant in 22% and 10% of ADC and SCC cases, respectively. Finally, TC PD-L1 expression was correlated with CD8 infiltrate. (p 

Conclusions

PD-L1 IHC expression appears to be more heterogeneous when assessed in the TS compared to the TC compartment, especially in SCC histology. Intra-tumor heterogeneity has to be taken into account when selecting patients for immunotherapy based on PD-L1 positivity or lymphocyte presence.

Clinical trial identification

Legal entity responsible for the study

University Hospital del Mar, Barcelona, Spain

Funding

Medical Oncology Department, University Hospital del Mar, Barcelona, Spain

Disclosure

D. Casadevall Aguilar: Is the recipient of a competitive grant "Beca FSEOM para la realización de tesis doctoral" awarded in October 2015 by the Spanish Society for Medical Oncology Foundation (Fundación SEOM). All other authors have declared no conflicts of interest.