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I.I. Wistuba



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    MINI 02 - Immunotherapy (ID 92)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MINI02.10 - Discussant for MINI02.06, MINI02.07, MINI02.08, MINI02.09 (ID 3300)

      10:45 - 12:15  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation
      • Slides

      Abstract not provided

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    MINI 09 - Drug Resistance (ID 107)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MINI09.06 - Oncogenic Drivers including RET and ROS1 plus PTEN Loss and MET by IHC in Patients with Lung Adenocarcinomas: Lung Cancer Mutation Consortium 2.0 (ID 2114)

      16:45 - 18:15  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation
      • Slides

      Background:
      The Lung Cancer Mutation Consortium (LCMC) 1.0 demonstrated multiplexed genomic platforms can assay 10 oncogenic drivers in tumor specimens from patients with lung adenocarcinomas. 28% of the patients with oncogenic drivers could be effectively targeted. The survival of these 275 patients treated with targeted agents was longer than the patients who were not treated with a targeted agent (Kris and Johnson JAMA 2014). The efficiency of Next-Generation Sequencing enables more comprehensive testing of additional aberrations with less tumor tissue. LCMC 2.0 was initiated to test tumor specimens for 12 oncogenic drivers and to provide the results to clinicians for treatment decisions and research purposes.

      Methods:
      The 16 site LCMC 2.0 is testing tumors from 1000 patients with lung adenocarcinomas in CLIA laboratories for mutations in KRAS, EGFR, HER2, BRAF, PIK3CA, AKT1, and NRAS, MET DNA amplification, and rearrangements in ALK as done in LCMC 1.0. The new genes that were added because of emerging information about potential therapeutic targets include MAP2K1 mutations, RET and ROS1 rearrangements, PTEN (MAb 138G4) loss and MET (MAb SP44) overexpression by immunohistochemistry (IHC). All patients were diagnosed with stage IIIB/IV lung adenocarcinoma after May 2012, had a performance status 0-2, and available tumor tissue.

      Results:
      Of 1073 patients registered, data is now reported for 759. The median age of the patients is 65 (23-90). The population includes 369 (55%) women; 164 (24%) never smokers, 399 (59%) former smokers, and 73 (11%) current smokers; 26 (4%) Asians, 58 (9%) African American, 548 (81%) Caucasian, and 43 (6%) of other races. As of April 2015 information on genomic and immunohistochemical changes for 675 eligible patients were recorded in our database. Alterations in oncogenic drivers were found in 45% of samples as follows: 159 KRAS (24%), 88 EGFR (13%), 25 ALK (4%), 19 BRAF (3%), 17 PIK3CA (3%), 9 HER2 (1%), 4 NRAS (1%) 0 AKT1, 28 had ≥ 2 findings (4%) and 25 MET DNA amplification (4%). The new genes studied in LCMC 2.0 revealed 1 MAP2K1 mutation (<1%), 19 RET (3%) and 9 ROS (1%) rearrangements, 94 had PTEN loss (14%), and 362 with MET overexpression (54%). As expected, PIK3CA mutations and PTEN loss by IHC were mutually exclusive in 109 of 111 (98%) patients’ tumors. Seventeen of the 23 (74%) with MET DNA amplification studied thus far with IHC had MET overexpression. Next-Generation platforms were used at 13 of 16 LCMC 2.0 sites.

      Conclusion:
      Next-Generation Sequencing is rapidly becoming routine practice at LCMC 2.0 centers with use going from 0 to 81% of sites since 2012. LCMC 2.0 identified additional targets (RET and ROS1 rearrangements and PTEN loss). PIK3CA and PTEN were largely mutually exclusive and an actionable oncogenic driver has been identified in the 45% of initial lung adenocarcinoma specimens. Supported by Free to Breathe

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    MINI 21 - Novel Targets (ID 133)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MINI21.07 - Oncogenic EZH2 Is an Actionable Target in Patients with Adenocarcinoma of the Lung (LUAD) (ID 3169)

      16:45 - 18:15  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation
      • Slides

      Background:
      The methyltransferase enhancer of zeste homolog 2 (EZH2) belongs to the polycomb repressive 2 complex (PRC2). EZH2 is upregulated in several malignancies including prostate, breast and lung cancer. The EZH2 protein forms one of the critical protein complexes of PRC2 by partnering with EED (embryonic ectoderm development) protein. This EED/EZH2 complex has been shown to interact with histone deacytelase (HDAC). This interaction is highly specific and HDAC does not interact with any other PRC2 protein complexes. In the present study, we investigated the link between EZH2 and HDAC in lung cancer cell lines and in human tumor tissue microarrays (TMAs). We also further investigated EZH2 as a marker for response to HDAC inhibitors.

      Methods:
      We analyzed EZH2 and HDAC1 mRNA expression in two lung adenocarcinoma datasets (MDACC n=152, and TCGA n=308), and correlated the gene expression with tumors’ clinico-pathological characteristics and patients’ outcome. To study the association of EZH2 and HDAC1 expression with response to the HDAC1 inhibitor suberanilohydroxamic acid (SAHA), we examined mRNA and protein expression by RT-PCR and Western blot, respectively, in twelve lung adenocarcinoma (LUAD) cell lines at baseline and after overexpression or knock-down of EZH2 or HDAC1 gene expression using siRNA. Response to (SAHA) in cell lines was measured by MTT assay and correlated with protein and mRNA expression levels of EZH2 and HDAC1.

      Results:
      Direct and positive correlation was found between EZH2 and HDAC1 expression NSCLC cell lines (P <0.0001). This correlation was confirmed in NSCLC specimens from MDACC (Spearman’s correlation r=0.416; p < 0.0001) and TCGA datasets (r=0.221; p <0.0001).Patients with high EZH2 and high HDAC1 expression in stage I NSCLC specimens of MDACC and TCGA datasets had lowest survival compared to the patients who had either or both low expressions. Overall survival in the univariate analysis (MDACC dataset; Hazard Ratio (HR)=2.97; p=0.031 and TCGA dataset; HR=2.6 and p=0.041) and multivariate analysis (MDACC; HR=2.92 and p=0.034 and TCGA; HR=3.17 p=0.016). When EZH2 expression was knock down, there was a significant reduction in HDAC1 expression; conversely, when HDAC1 was knocked down EZH2 expression was also decreased. These concordant change in expression was seen both at the protein and mRNA level. Importantly, while all 8 cell lines with high EZH2 protein expression responded to SAHA treatment with average inhibition rate reaching 73.1%, three out of four cell lines with low EZH2 expression had a significantly lower response rate to SAHA inhibition with average inhibition rate 43.2% (P<0.0001). Additionally, altering the expression of EZH2 concordantly altered the sensitivity to SAHA i. e. forced increased expression of EZH2 increased the response to SAHA and vice versa.

      Conclusion:
      Our data suggest that EZH2 and HDAC expression are correlated in LUAD cell lines in human tissue microarrays and overexpression of both is a negative prognostic indicator. Additionally we show that increased EZH2 expression predicts for response to HDAC inhibitors and thus could serve as a biomarker for selecting LUAD patients with HDAC inhibitors.

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    MS 21 - Immunotherapy Predictive Biomarkers (ID 39)

    • Event: WCLC 2015
    • Type: Mini Symposium
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MS21.03 - Assessment of Immune Cells in Tumor Biopsies as a Biomarker (ID 1943)

      14:15 - 15:45  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation

      Abstract:
      Multiple genetic and epigenetic changes in several cancer types cause resistance to immune attack of tumors by inducing specific T cells tolerance and by expressing ligands that engage inhibitory receptors and block T cells activation, all resulting on T-cells anergy or exhaustion within the tumor microenvironment (1). In this process, programmed death 1 (PD-1) protein, a T-cell co-inhibitory receptor, and one of its ligands, PD-L1 (B7-H1 or CD274), play a pivotal role in the ability of tumor cells to evade the host’s immune system. Antibody-mediated blockade PD-1/PD-L1 induced durable tumor regression and prolonged disease stabilization in non-small cell carcinoma (NSCLC) (2). Although these studies have reported correlations between PD-L1 immunohistochemical (IHC) expression levels on NSCLC tumor cells and clinical responses to PD-1 and PD-L1 inhibitors, there are patients with negative PD-L1 expression tumors who have showed similar responses than patients with positive expression. Recently, it has been shown that across multiple cancer types, including NSCLC, responses to anti-PD-L1 therapy were observed in patients with tumors expressing high levels of PD-L1, especially when PD-L1 was expressed by tumor-associated infiltrating cells (TAICs). Altogether, these findings suggest that there are other factors in the tumor microenvironment, including tumor infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) that may drive responses to anti-PD-1/PD-L1 therapies, and be involved in lung cancer pathogenesis and progression. A number of studies have characterized the PD-L1 protein expression by immunohistochemistry (IHC) or immunofluorescence (IF) in all NSCLC stages using formalin-fixed and paraffin-embedded (FFPE) tumor tissues, and correlated those findings with patient’s outcome, and in a limited number of cases with response to immunotherapy (3, 4). Those studies differ on the type of specimens (whole histology sections vs. tissue microarrays [TMAs]), the protein expression analysis (IHC vs. IF), and the quantification assessment (image analysis vs. microscope observation). Only few studies have attempted to correlate the expression of PD-L1 and TAICs, particularly TILs, using a limited number of IHC markers (e.g., CD8, CD45) (5). Up to date, there is no published study in which a comprehensive panel of immune markers, including PD-L1, has been performed attempting to develop a clinical relevant immuno-score system in surgically resected NSCLCs and explore their role as predictive markers of response to immunotherapy. We will present data on the characterization of TAICs in lung cancer tumor specimens using a large panel of markers (PD-L1, PD-1, CD3, CD4, CD8, CD45RO, CD57, Granzyme B, FOXP3, OX-40, and CD68) examined by both uniplex IHC and multiple immunofluorescence (IF) methodologies, and quantitated using image analysis systems (Aperio, Vectra and MultiOmyx). In surgically resected NSCLC tumor tissues the analysis was performed at both peri-tumoral and intra-tumoral compartments, and those data provided interesting data on the spatial distribution of TAICs and the expression of immune checkpoints in lung tumors. Our approach allowed us to devise an immuno-score system for lung cancer tissue specimens using both surgically resected and small diagnostic biopsies (core needle biopsies, CNBs) that correlated with clinical, pathological and molecular features of tumors. References: 1. Mellman I, Coukos G, Dranoff G: Cancer immunotherapy comes of age. Nature 2011, 480:480-9. 2. Topalian SL, Hodi FS, Brahmer JR, Gettinger SN, Smith DC, McDermott DF, Powderly JD, Carvajal RD, Sosman JA, Atkins MB, Leming PD, Spigel DR, Antonia SJ, Horn L, Drake CG, Pardoll DM, Chen L, Sharfman WH, Anders RA, Taube JM, McMiller TL, Xu H, Korman AJ, Jure-Kunkel M, Agrawal S, McDonald D, Kollia GD, Gupta A, Wigginton JM, Sznol M: Safety, activity, and immune correlates of anti-PD-1 antibody in cancer. The New England journal of medicine 2012, 366:2443-54. 3. Herbst RS, Soria JC, Kowanetz M, Fine GD, Hamid O, Gordon MS, Sosman JA, McDermott DF, Powderly JD, Gettinger SN, Kohrt HE, Horn L, Lawrence DP, Rost S, Leabman M, Xiao Y, Mokatrin A, Koeppen H, Hegde PS, Mellman I, Chen DS, Hodi FS: Predictive correlates of response to the anti-PD-L1 antibody MPDL3280A in cancer patients. Nature 2014, 515:563-7. 4. Taube JM, Klein A, Brahmer JR, Xu H, Pan X, Kim JH, Chen L, Pardoll DM, Topalian SL, Anders RA: Association of PD-1, PD-1 Ligands, and Other Features of the Tumor Immune Microenvironment with Response to Anti-PD-1 Therapy. Clinical cancer research : an official journal of the American Association for Cancer Research 2014, 20:5064-74. 5. Schalper KA, Brown J, Carvajal-Hausdorf D, McLaughlin J, Velcheti V, Syrigos KN, Herbst RS, Rimm DL. Objective measurement and clinical significance of TILs in non-small cell lung cancer. J Natl Cancer Inst. 2015 Feb 3;107(3).

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    ORAL 13 - Immunotherapy Biomarkers (ID 104)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      ORAL13.07 - EMT Is Associated with an Inflammatory Tumor Microenvironment with Elevation of Immune Checkpoints and Suppressive Cytokines in Lung Cancer (ID 2134)

      16:45 - 18:15  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation
      • Slides

      Background:
      Promising results in the treatment of NSCLC have been seen with immunomodulatory agents targeting immune checkpoints, such as programmed cell death 1 (PD-1) or programmed cell death 1 ligand (PD-L1). However, only a select group of patients respond to these interventions. The identification of biomarkers that predict clinical benefit to immune checkpoint blockade is critical to successful clinical translation of these agents. Epithelial-mesenchymal transition (EMT) is a key process driving metastasis and drug resistance. Previously we have developed a robust EMT gene signature, highlighting differential patterns of drug responsiveness for epithelial and mesenchymal tumor cells.

      Methods:
      We conducted an integrated analysis of gene expression profiling from three independent large datasets, including The Cancer Genome Atlas (TCGA) of lung and two large datasets from MD Anderson Cancer Center, Profiling of Resistance patterns and Oncogenic Signaling Pathways in Evaluation of Cancers of the Thorax (named PROSPECT) and the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (named BATTLE-1). Comprehensive analysis of mRNA gene expression, reverse phase protein array (RPPA), immunohistochemistry, in vivo mouse models and correlation with clinical data were performed.

      Results:
      EMT is highly associated with an inflammatory tumor microenvironment in lung adenocarcinoma, independent of tumor mutational burden. We found immune activation co-existent with elevation of immune checkpoint molecules, including PD-L1, PD-L2, PD-1, TIM-3, BTLA and CTLA-4, along with increases in tumor infiltration by CD4+Foxp3+ regulatory T cells in lung adenocarcinomas that displayed an EMT phenotype. Similarly, IL-6 and indoleamine 2, 3-dioxygenase (IDO) were elevated in these tumors. We demonstrate that in murine models of lung adenocarcinoma, many of these changes are recapitulated by modulation of the miR-200/ZEB1 axis, a known regulator of EMT. Furthermore, B7-H3 is found to negatively correlate with overall survival and recurrence free survival, indicating a potential new therapeutic target in lung adenocarcinoma in the future.

      Conclusion:
      EMT, commonly related to cancer metastasis and drug resistance, is highly associated with an inflammatory tumor microenvironment with elevation of multiple targetable immune checkpoints and that is regulated at least in part by the miR-200/ZEB1 axis. These findings suggest that EMT may have potential utility as a biomarker selecting patients more likely to benefit from immune checkpoint blockade agents and other immunotherapies in NSCLC and possibly a broad range of other cancers.

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    ORAL 21 - Biology - Moving Beyond the Oncogene to Oncogene-Modifying Genes (ID 118)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      ORAL21.02 - Landscape and Functional Significance of KRAS Co-Mutations in Lung Adenocarcinoma (LUAC) (ID 3224)

      10:45 - 12:15  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation
      • Slides

      Background:
      The biological heterogeneity of KRAS-mutant LUAC represents a major impediment to the successful implementation of targeted therapeutic strategies for this clinically challenging group of lung cancer patients. Through integrative, multi-platform analysis of large scale omics data we recently identified three major subsets of KRAS-mutant LUAC defined on the basis of co-occurring genomic alterations in STK11/LKB1 (KL subgroup), TP53 (KP) and CDKN2A/B (KC), the latter coupled with low expression of the TTF1 transcription factor. We further demonstrated subset-specific molecular dependencies, patterns of immune system engagement and therapeutic vulnerabilities. Here, we extend these findings through comprehensive analysis of a wide panel of KRAS co-mutations and assess the impact of key co-mutations on facets of the malignant phenotype including flux through the MAPK and PI3K/AKT pathways and heterotypic interactions with the host immune system.

      Methods:
      Our datasets consisted of 431 tumors from TCGA (122 KRAS-mutant), 41 additional chemo-naive KRAS-mutant LUACs (PROSPECT dataset) and 36 platinum-refractory KRAS-mutant LUACs from the BATTLE-2 clinical trial. Significant KRAS co-mutations were identified on the basis of a P value threshold of ≤0.05 (Fisher’s exact test) coupled with a baseline prevalence of ≥3%. RNASeq data were downloaded directly from the TCGA site. Expression profiling of PROSPECT tumors was performed using the Illumina Human WG-6 v3 BeadChip Array whereas BATTLE-2 tumors were profiled using the GeneChipâHuman Gene 1.0 ST Array from Affymetrix. Generation of MAPK and PI3K proteomic scores, based on Reverse Phase Protein Array (RPPA) data, has been previously reported.

      Results:
      Our analysis identified somatic mutations in 31 genes as significantly co-mutated with KRAS in LUAC samples. Among them, co-mutations in STK11/LKB1 (P=0.00011) and ATM (P=0.0004) predominated. Somatic mutations in ERBB4 (P=0.0059), encoding a member of the ErbB family of receptor tyrosine kinases and MAP3K4 (P=0.0017) were also enriched in KRAS-mutant LUAC. We assessed the impact of KRAS co-mutations on the amplitude and directionality of signaling downstream of mutant KRAS using the proteomic “MAPK score“ and “PI3K score” as surrogates of effector pathway activation. Interestingly, co-mutations in ERBB4 were associated with significantly suppressed flux through the MAPK pathway (P=0.0024, t-test). Somatic mutations in other genes, including CAMSAP2, were associated with suppressed signaling through both the MAPK (P=0.00876, t-test) and PI3K-AKT (P=0.0032, t-test) cascades. Finally, within KRAS-mutant tumors, co-mutations in NLRC5, a master transcriptional regulator of MHC Class I molecules were associated with reduced mRNA expression of several of its classical target genes. In addition, low mRNA expression of NLRC5 correlated strongly with reduced expression of key components of the antigen presentation pathway across multiple independent datasets of chemotherapy naïve and platinum refractory KRAS-mutant tumors and cell lines. Thus, in addition to cell autonomous effects, co-mutations can also impinge on the reciprocal relationship between malignant cells and their immune microenvironment.

      Conclusion:
      Our work identifies a compendium of KRAS co-mutations that impact classical and emerging cancer hallmarks, including evasion of the host immune response. Systematic interrogation of the functional impact of prevalent KRAS co-mutations is essential for the development of personalized treatment approaches for this heterogeneous group of tumors.

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    ORAL 42 - Drug Resistance (ID 160)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      ORAL42.04 - Rictor Alterations Elicit Mechanisms of Survival Advantage and Resistance to Targeted Therapy in Non-Small Cell Lung Cancer (NCSLC) (ID 2991)

      18:30 - 20:00  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation

      Background:
      Rictor (RPTOR independent companion of MTOR, complex 2) is a highly conserved protein and is a critical component for assembly and functionality of the mTORC2 complex. Alterations of the PI3K/mTOR/AKT pathway are hallmark of many cancer types, underscoring the potential important role of Rictor. The goal of our current study was to characterize the functional consequences of genomic alterations of Rictor in advanced refractory NSCLC. Our preliminary data suggest that Rictor alterations have the potential to, not only signal canonically (via activation of AKT), but also provide cancer cells with alternate, more advantageous oncogenic signaling via non-canonical mechanisms.

      Methods:
      We correlated genomic data (DNA next generation sequencing (NGS), Foundation Medicine, Inc) gene expression profiling, and clinical outcome in the context of the ongoing BATTLE-2 clinical trial of targeted therapies in chemo-refractory NSCLC(198 cases). We further (1) surveyed early stage NSCLC cases(230 cases) in The Cancer Genome Atlas (TCGA) database to perform two-way hierarchical clustering comparing gene expression profiling in amplified vs diploid cases; (2) utilized a single-nucleotide polymorphism array to select Rictor amplified and diploid NSCLC cell lines; (3) assessed Rictor protein and RNA expression by Western blot and qRT-PCR, respectively; (4) performed Rictor knockdown (siRNA), and (5) performed drug sensitivity to targeted therapies by MTS assay.

      Results:
      In the Battle-2 cases, we identified 15% of Rictor alterations (9% gene amplifications, 6.6% mutations, non-concomitant). Among the mutations, 1 was mapped to an N-terminal phosphorylation site, while all others are of unknown significance to date. Rictor alterations were significantly associated with lack of 8-week disease control in the AKTi+MEKi therapeutic arm. In the TCGA we found: (1) 10% Rictor amplifications and 3% mutations; (2) significant correlation between amplification and elevated Rictor gene expression; (3) a putative functional gene expression signature associated with Rictor amplification. In diploid cell lines we found concordance between AKT phosphorylation and activation of other downstream mTORC2 targets (i.e. SGK1 and PKCα), but in Rictor amplified cell lines we witnessed a discordant activation of these pathways. Furthermore, following Rictor knockdown in our amplified cell lines, a significant reduction of colony formation, migratory, and invasive potential was seen in a pathway-differential manner. Thus, suggesting that Rictor amplifications may provide survival advantage in select cancer cells by tipping the signaling balance toward a non-canonical oncogenic pathway (AKT-independent[I1] ).Also in a differential pathway manner, Rictor gene amplification and overexpression contributed to resistance to a number of targeted therapies

      Conclusion:
      Rictor alterations may constitute a potential novel mechanism of targeted therapy resistance via the activation of non-canonical signaling pathways. These alterations could define new molecular NSCLC subtypes with distinct biology that expose unique avenues for therapeutic implication. Ongoing studies are exploring therapeutic vulnerabilities, non-canonical signaling and Rictor mutations.

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    P2.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 234)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      P2.04-066 - Programmed Cell Death Ligand 1 (PD-L1) Overexpression and Low Immune Infiltrate Score Correlate with Poor Outcome in Lung Adenocarcinoma (ID 776)

      09:30 - 17:00  |  Author(s): I.I. Wistuba

      • Abstract

      Background:
      PD-L1 is a key immunoregulatory checkpoint which suppresses cytotoxic immune response in a variety of physiologic and pathologic conditions. Thus, inhibition of PD-L1 can lead to reactivating tumor immunity and assist to cancer therapy. PD-L1 overexpression in the tumor cells has been correlated to a lessened immune response and consequent worse prognosis in a variety of cancers. To better understand the immune profiling of PD-L1 expression and its interplay with immune cells, we analyzed the correlation between image analysis-based immunohistochemical (IHC) expression of PD-L1 and tumor infiltrating immune cells density in surgically resected non-small cell lung carcinomas (NSCLC), and the correlation with clinical and pathological features, including patient outcome.

      Methods:
      IHC for PD-L1, PD-1, CD3, CD4, CD8, CD45RO, CD57, CD68, Granzyme B and FOXP3 were performed in 254 surgical resected stages I-III NSCLC, Adenocarcinoma (ADC=146) and Squamous cell Carcinoma (SqCC=108) from formalin-fixed and paraffin-embedded tissues. PD-L1 membrane expression on tumor cells and density of inflammatory cells were quantified using image analysis in intra-tumoral (IT) and peri-tumoral (PT) compartments. H-score > 5 was used as a cut-off for positive PD-L1 expression and an immune-score (IMS) using CD8/CD4/CD68 was devised. PD-L1 expression and inflammatory cells were correlated with clinico-pathologic features and patient outcomes.

      Results:
      Positive PD-L1 expression was seen in 26.84% (n=69) of the entire cohort, 23.29% (n=34) of 146 ADC and 23.40% (n=35) of 115 SqCC. In ADC, higher levels of PD-L1 expression were detected in tumors with solid histology pattern compared with other histology patterns (P=0.034), and in lifetime smokers compared with non-smokers (P<0.0001). In SqCC PD-L1 expression was positive correlation with tumor size (Rho=0.19471, P=0.0435). In overall, PD-L1 expression correlated positively with inflammatory cell density in both IT and PT compartments in ADC and SqCC. Patients with KRAS mutation (P=0.00058), solid tumor (P<0.0001) or smoker (P = 0.0446) were more likely to have positive PD-L1 expression tumor cells in ADC. No correlation was detected between EGFR mutation and immune markers. Using PD-L1 and CD8/CD4/CD68 IMS expression levels, in ADC and SqCC, we identified 4 groups of tumors (Table 1). Multivariate Cox proportional hazard regression analysis demonstrated that tumors with high PD-L1 expression and low IMS in ADC exhibited significantly poor recurrence-free (HR=4.299; P=0.0101) and overall survival (HR=5.632; P=0.0010).

      Table 1. Summary of the correlation between PD-L1 expression levels and immune-score (IMS=CD8/CD4/CD68) in adenocarcinoma (ADC) and squamous cells carcinoma (SQCC).
      PDL-1 H-score (ADC) IMS (Low) IMS (High) Total
      <5 61 (41.78%) 51 (34.93%) 112 (76.71%)
      ≥5 8 (5.48%) 26 (17.81%) 34 (23.29%)
      Total 69 (47.26%) 77 (52.74%) 146 (100.0%)
      PDL-1 H-score (SqCC)
      <5 37 (34.30%) 36 (33.30%) 73 (67.60%)
      ≥5 17 (15.70%) 18 (16.70%) 35 (32.40%)
      Total 54 (50.00%) 54 (50.00%) 108 (100.0%)


      Conclusion:
      Higher PD-L1 expression is associated with solid pattern in adenocarcinoma and higher level of tumoral immune infiltrate. We developed an immune score which when combined with PD-L1 expression significantly correlates with patient outcome in surgically resected ADCs. (Supported by grants UT-Lung SPORE P50CA70907 and CPRIT RP120713).

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    PC 02 - Pro vs Con: Is There a Role for EGFR TKIs in EGFR Mutation Negative Disease? / Pro vs Con: Whole Exome Sequencing vs. Selected Testing (e.g., ALK and EGFR) (ID 48)

    • Event: WCLC 2015
    • Type: Pro Con
    • Track: Treatment of Advanced Diseases - NSCLC
    • Presentations: 1
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      PC02.03 - Whole Exome Sequencing vs. Selected Testing (e.g., ALK and EGFR) - Pro (ID 2032)

      14:15 - 15:45  |  Author(s): I.I. Wistuba

      • Abstract
      • Presentation

      Abstract not provided

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