Abstract 1291
Background
The efficacy of immunotherapy treating EGFR-positive non-small cell lung cancer (NSCLC) patients has been proved to be limited. However, a series of mutant-patients could be benefit from PD-1 blockade. Therefore, this study evaluated the immune microenvironment in NSCLC with uncommon EGFR mutation, and explored the prospect of immunotherapy in this cohort.
Methods
We retrospectively evaluated the expression of PD-L1, CD4 and CD8 in NSCLC patients who harbored uncommon EGFR mutation at Zhejiang Cancer Hospital between April 2016 and September 2017. The association with clinical factors and outcomes were also explored, as well as the effectiveness of immunotherapy in uncommon mutation-positive cases.
Results
Among the 600 NSCLC patients with EGFR mutation, we retrospectively collected 49 (8.2%) cases bearing uncommon mutation. In total, 49.0% (24/49) of NSCLC patients showed a strong PD-L1 expression in tumor cells, which was significantly higher than common sensitive (19del and L858R) or negative EGFR mutation (49.0% vs 12.1% vs 26.3%, respectively, P < 0.05). Furthermore, positive PD-L1 expression was associated with a significantly shortened OS when compared with the negative PD-L1 expression (20.0 vs 44.3 months, P = 0.006). And PD-L1 positivity was predominantly observed among patients with high CD8 expression rather than low cases (72.0% vs 25.0%, P = 0.001). Notably, we found PD-L1 and CD8 dual-positive cases demonstrated the worst prognosis (OS: 19.3[dual-positive] vs 31.1[single-positive] vs 44.3[dual-negative] months, P = 0.023). Additionally, this approach revealed PD-L1 and CD8 positivity were not associated with the response to EGFR-TKIs, playing no role in the de novo resistance of EGFR-TKIs among the uncommon mutated patients. Finally, one patient harboring EGFR G719A mutation with PD-L1 and CD8 dual positivity experienced a favorable response to anti-PD-1 therapy.
Conclusions
This study revealed the expression of PD-L1, CD4 and CD8 in uncommon EGFR-mutated NSCLC patients. The findings indicated the reshaping of an inflamed immune phenotype characterized by PD-L1 and CD8 dual positivity and suggest potential therapeutic sensitivity to PD-1 blockade.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2963 - Analytical performance of the Resolution-HRD plasma assay used to identify mCRPC patients with biallelic disruption of DNA repair genes for treatment with niraparib
Presenter: Ira Pekker
Session: Poster Display session 3
Resources:
Abstract
3523 - Results of a global external quality assessment scheme for EGFR testing on liquid biopsy
Presenter: Nicola Normanno
Session: Poster Display session 3
Resources:
Abstract
3295 - Clinical impact of plasma Next-Generation Sequencing (NGS) in advanced Non-small cell lung cancer (aNSCLC)
Presenter: Laura Bonanno
Session: Poster Display session 3
Resources:
Abstract
5632 - Feasibility study of a ctEGFR prototype assay on the fully automated Idylla™ platform
Presenter: Martin Reijans
Session: Poster Display session 3
Resources:
Abstract
3614 - Enhanced Access to EGFR Molecular Testing in NSCLC using a Cell-Free DNA Tube for Liquid Biopsy
Presenter: Theresa May
Session: Poster Display session 3
Resources:
Abstract
5664 - Analysis of circulating tumor DNA in paired plasma and sputum samples of EGFR-mutated NSCLC patients
Presenter: Christina Grech
Session: Poster Display session 3
Resources:
Abstract
4945 - Liquid biopsy and Array Comparative Genomic Hybridization (aCGH)
Presenter: Panagiotis Apostolou
Session: Poster Display session 3
Resources:
Abstract
5746 - Next-generation sequencing panel verification to detect low frequency single nucleotide and copy number variants from mixing cell line studies
Presenter: Rocio Rosas-Alonso
Session: Poster Display session 3
Resources:
Abstract
5901 - Automated rarefaction analysis for precision B and T cell receptor repertoire profiling from peripheral blood and FFPE-preserved tumor
Presenter: Luca Quagliata
Session: Poster Display session 3
Resources:
Abstract
2027 - A Heptamethine cyanine dye is a potential diagnostic marker for Myeloid-Derived Suppressor Cells
Presenter: Chaeyong Jung
Session: Poster Display session 3
Resources:
Abstract