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The number of genomic alterations required for targeted therapy of non-squamous non-small cell lung cancer (NS-NSCLC) patients has increased and become more complex these last few years. These molecular abnormalities lead to treatment that provides improvement in overall survival for certain patients. However, these treated tumors inexorably develop mechanisms of resistance, some of which can be targeted with new therapies. The characterization of the genomic alterations needs to be performed in a short turnaround time (TAT), as indicated by the international guidelines. The origin of the tissue biopsies used for the analyses is diverse, but their size is progressively decreasing due to the development of less invasive methods. In this respect, the pathologists are facing a number of different challenges requiring them to set up efficient molecular technologies while maintaining a strategy that allows rapid diagnosis. We report here our experience concerning the development of an optimal workflow for genomic alteration assessment as reflex testing in routine clinical practice at diagnosis for NS-NSCLC patients by using an ultra-fast-next generation sequencing approach (Ion Torrent Genexus Sequencer, Thermo Fisher Scientific). We show that the molecular targets currently available to personalized medicine in thoracic oncology can be identified using this system in an appropriate TAT, notably when only a small amount of nucleic acids is available. We discuss the new challenges and the perspectives of using such an ultra-fast NGS in daily practice.

Rationale: The characterization of new theranostic biomarkers is crucial to improving the clinical outcome of patients with advanced lung cancer. Here, we aimed at characterizing the P2RX7 receptor, a positive modulator of the anti-tumor immune response, in patients with lung adenocarcinoma. Methods: The expression of P2RX7 and its splice variants was analyzed by RT-qPCR using areas of tumor and non-tumor lung adenocarcinoma (LUAD) tissues on both immune and non-immune cells. The biological activity of P2RX7 was studied by flow cytometry using fluorescent dyes. Bi-molecular fluorescence complementation and confocal microscopy were used to assess the oligomerization of P2RX7. Tumor immune infiltrates were characterized by immunohistochemistry. Results: Fifty-three patients with LUAD were evaluated. P2RX7A, and 3 alternative splice variants were expressed in LUAD tissues and expression was down regulated in tumor versus adjacent non-tumor tissues. The protein retained biological activity only in immune cells. The P2RX7B splice variant was differentially upregulated in immune cells (P < 0.001) of the tumor and strong evidence of oligomerization of P2RX7A and B was observed in the HEK expression model, which correlated with a default in the activity of P2RX7. Finally, LUAD patients with a high level of P2RX7B had non-inflamed tumors (P = 0.001). Conclusion: Our findings identified P2RX7B as a new theranostic tool to restore functional P2RX7 activity and open alternative therapeutic opportunities to improve LUAD patient outcome.

The evaluation of an increasing number of diagnostic and predictive markers is playing a central role in precision thoracic oncology. Multiplex immunohistochemistry (mIHC), alongside next-generation sequencing, is ideally situated for this purpose and maximizes tumor tissue preservation for molecular analyses that use increasingly large panels. However, the standardization and validation of mIHC that supports routine clinical laboratory processes are mandatory. After a previous proof-of-concept study, we now (i) optimized two automated four-plex assays on a commercially available IHC autostainer for use in daily practices worldwide and (ii) evaluated the repeatability and concordance of the assessment of the cell density.Two four-plex mIHC assays [i) TTF1, p40, PD-L1, CD8; and, ii) ALK, ROS1, BRAFV600E, NTRK] were optimized on the BenchMark ULTRA autostainer (Ventana Medical Systems, Inc.), as determined in comparison to conventional IHC chromogenic assays. Intra-site repeatability was evaluated on serial tumor sections from non-small cell lung carcinomas (NSCLC). The concordance was assessed by linear fit to plots of the percentage staining evaluated on tumor sections from 89 NSCLC patients.Following optimization, an average concordance for a staining rate of 95.4% was achieved between conventional IHC and mIHC across all selected markers. Assessment of intra-site repeatability showed strong concordance for all these markers (average, ROur optimized mIHC assay gave a sensitive and repeatable assessment of two panels of eight diagnostic and predictive biomarkers for NSCLC. The availability of standardized protocols to determine these biomarkers on a widely available IHC platform will expand the number of pathology laboratories able to determine the eligibility of patients with NSCLC for targeted treatment or immunotherapy in a reliable and concordant manner, thus providing a unique sample-sparing tool to characterize limited tissue samples in thoracic oncology.

Background NGS from plasma samples in non-squamous cell lung carcinoma (NSCC) can aid in the detection of actionable genomic alterations. However, the absolute clinical value of NGS in liquid biopsy (LB) made at baseline is currently uncertain. We assessed the impact of plasma-based NGS using an in-house test and an outsourced test in comparison to a routine molecular pathology workflow. Methods Twenty-four advanced/metastatic treatment-naïve NSCC patients were prospectively included. NGS analyses were conducted both in-house using the Oncomine cfTNA Panel and in an external testing center using the Foundation Liquid assay. NGS analysis and/or specific molecular based assays were conducted in parallel on tissue or cytological samples. Results Both LB tests were well correlated. Tissue NGS results were obtained in 67% of patients and demonstrated good correlation with LB assays. Activating EGFR mutations were detected using LB tests in three patients. PD-L1 expression assessed in tissue sections enabled the initiation of pembrolizumab treatment in five patients. Conclusion NGS from LB is feasible in routine clinical practice using an in-house or an outsourced test at baseline. However, the impact on therapy selection was limited in this small series of patients and LB was not able to replace tissue-based testing in our hands.

Background: Assessment of actionable EGFR mutations is mandatory for treatment-naïve advanced or metastatic non-squamous lung carcinoma (NSLC), but the results need to be obtained in less than 10 working days. For rapid EGFR testing, an EGFR-specific polymerase chain reaction (PCR) assay is an alternative and simple approach compared to next generation sequencing (NGS). Here, we describe how a rapid EGFR-specific PCR assay can be implemented in a single laboratory center (LPCE, Nice, France) as reflex testing in treatment-naïve NSLC. Methods: A total of 901 biopsies from NSLC with more than 10% of tumor cells were prospectively and consecutively evaluated for EGFR mutation status between November 2017 and December 2019 using the Idylla system (Biocartis NV, Mechelen, Belgium). NGS was performed for nonsmokers with NSLC wild type for EGFR, ALK, ROS1, and BRAF and with less than 50% PD-L1 positive cells using the Hotspot panel (Thermo Fisher Scientific, Waltham, MA, USA). Results: Results were obtained from 889/901 (97%) biopsies with detection of EGFR mutations in 114/889 (13%) cases using the Idylla system. Among the 562 EGFR wild type tumors identified with Idylla, NGS detected one actionable and one nonactionable EGFR mutation. Conclusions: Rapid and targeted assessment of EGFR mutations in treatment-naïve NSLC can be implemented in routine clinical practice. However, it is mandatory to integrate this approach into a molecular algorithm that allows evaluation of potentially actionable genomic alterations other than EGFR mutations.

Background: Circulating tumor cells (CTCs) hold potential for noninvasive diagnosis, prognosis and prediction testing in non-small cell lung cancer (NSCLC) patients. Minimizing degradation or loss of CTCs is pivotal for detection and profiling of the low abundance and fragile CTCs, particularly in clinical trials. We prospectively investigated (NCT02372448) whether a new blood collection device performed better compared to commonly used K3EDTA tubes, when subjected to long-term sample storage. Methods: Blood samples were drawn into K3EDTA and blood collection tubes (BCT) (Streck), and filtered by the Isolation by SizE of Tumor/Trophoblastic Cells (ISET® system), for CTC detection in two study populations of NSCLC patients; the training set of 14 patients with stage II/IV NSCLC, and the validation set of 36 patients with stage IV NSCLC). MET expression was evaluated by immunocytochemistry (ICC) and anaplastic lymphoma kinase (ALK) gene rearrangement by break-apart fluorescence in situ hybridization (FISH) on ISET-enriched CTCs. Results: Blood processed after 24 h and 48 h in BCT tubes showed stable CTCs counts and integrity, whereas CTCs in K3EDTA tubes showed an altered morphology in all patients. CTCs recovered in BCT or K3EDTA tubes at 24 and 48 h were evaluable by ICC for MET expression and by FISH for ALK rearrangement. Conclusions: The BCT tubes gave a high yield and preserved the integrity of CTCs after 24 and 48 h of storage at room temperature, which facilitate their molecular characterization in NSCLC patients entering clinical trials.

MicroRNAs (miRs) participate in tumor growth and dissemination by regulating expression of various target genes. MiR-223-3p is suspected of being involved in head and neck squamous cell carcinoma (HNSCC) growth although its precise role has not been elucidated. In this study, we showed that miR-223-3p is present in biopsies of HNSCC patients and that its presence is correlated with high neutrophil infiltrate. We found that overexpression of miR-223-3p slightly increased proliferation of the CAL27 squamous carcinoma cell line both in vitro and in vivo. Moreover, miR-223-3p induced CAL27 apoptosis in an orthotopic xenograft mouse model, counteracting the proliferative effect and resulting in no impact on overall tumor growth. We analyzed the effect of miR-223-3p overexpression on signaling pathways and showed that it induced pERK2, pAKT and AKT, consistent with an increase in cell proliferation. In addition, we found that miR-223-3p reduced the STAT3 level correlating with increased cell apoptosis and inhibited vasculature formation. In HNSCC tissues, miR-223-3p expression was inversely correlated to CD31, highlighting the relationship between miR-223 and vessel formation. Finally, we studied the effect of miR-223-3p on response to selected anticancer agents and showed that cells expressing miR-223-3p are more resistant to drugs, notably cetuximab. In conclusion, our study is the first to show the antiangiogenic properties of miR-223-3p in HNSCC patients and to question whether expression levels of miR-223-3p can be evaluated as an indicator of eligibility for non-treatment of HNSCC patients with cetuximab.

Introduction The detection of a ROS1 rearrangement in advanced and metastatic lung adenocarcinoma (LUAD) led to a targeted treatment with tyrosine kinase inhibitors with favorable progression-free survival and overall survival of the patients. Thus, it is mandatory to screen for the ROS1 rearrangement in all these patients. ROS1 rearrangements can be detected using break-apart fluorescence in situ hybridization (FISH), which is the gold standard; however, ROS1 immunohistochemistry (IHC) can be used as a screening test because it is widely available, easy and rapid to perform, and cost-effective. Methods We evaluated the diagnostic accuracy and interpathologist agreement of two anti-ROS1 IHC clones, SP384 (Ventana, Tucson, Arizona) and D4D6 (Cell Signaling, Danvers, Massachusetts), in a training cohort of 51 positive ROS1 FISH LUAD cases, and then in a large validation cohort of 714 consecutive cases of LUAD from six routine molecular pathology platforms. Results In the two cohorts, the SP384 and D4D6 clones show variable sensitivity and specificity rates on the basis of two cutoff points greater than or equal to 1+ (all % tumor cells) and greater than or equal to 2+ (>30% stained tumor cells). In the validation cohort, the D4D6 yielded the best accuracy for the presence of a ROS1 rearrangement by FISH. Interpathologist agreement was moderate to good (interclass correlation 0.722–0.874) for the D4D6 clone and good to excellent (interclass correlation: 0.830–0.956) for the SP384 clone. Conclusions ROS1 IHC is an effective screening tool for the presence of ROS1 rearrangements. However, users must be acutely aware of the variable diagnostic performance of different anti-ROS1 antibodies before implementation into routine clinical practice.

In the last few years, the treatment of patients with non-small cell lung cancer (NSCLC) has impressively benefitted from immunotherapy, in particular from the inhibition of immune checkpoints such as programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1). However, despite the significant survival benefit for some patients with advanced NSCLC, the objective response rates (ORRs) remain relatively low no more than 20-30% with a large proportion of patients demonstrating primary resistance. Although the selection of NSCLC patients for the first-line treatment is currently guided by the expression of PD-L1 in tumor cells as detected by immunohistochemistry, this is not the case for the second-line setting. Moreover, the sensitivity and specificity of PD-L1 expression is modest which has prompted the search for additional predictive biomarkers. In this context, the assessment of the tumor mutational burden (TMB), defined as the total number of nonsynonymous mutations in the coding regions of genes, has recently emerged as an additional powerful biomarker to select patients for immunotherapy. The purpose of our review is to highlight the recent advances as well as the challenges and perspectives in the field of TMB and immunotherapy for patients with NSCLC.

Tumor mutational burden (TMB) has emerged as an important potential biomarker for prediction of response to immune-checkpoint inhibitors (ICIs), notably in non-small cell lung cancer (NSCLC). However, its in-house assessment in routine clinical practice is currently challenging and validation is urgently needed. We have analyzed sixty NSCLC and thirty-six melanoma patients with ICI treatment, using the FoundationOne test (FO) in addition to in-house testing using the Oncomine TML (OTML) panel and evaluated the durable clinical benefit (DCB), defined by &gt, 6 months without progressive disease. Comparison of TMB values obtained by both tests demonstrated a high correlation in NSCLC (R2 = 0.73) and melanoma (R2 = 0.94). The association of TMB with DCB was comparable between OTML (area-under the curve (AUC) = 0.67) and FO (AUC = 0.71) in NSCLC. Median TMB was higher in the DCB cohort and progression-free survival (PFS) was prolonged in patients with high TMB (OTML HR = 0.35, FO HR = 0.45). In contrast, we detected no differences in PFS and median TMB in our melanoma cohort. Combining TMB with PD-L1 and CD8-expression by immunohistochemistry improved the predictive value. We conclude that in our cohort both approaches are equally able to assess TMB and to predict DCB in NSCLC.

Background High expression of programmed death ligand-1 (PD-L1) on tumor cells (TC) and/or on tumor-infiltrating immune cells (IC) is associated with a high response rate in patients with advanced nonsmall-cell lung cancer (NSCLC) treated with PD-L1 inhibitors. The use of a PD-L1 immunohistochemical (IHC) test in determining the responsiveness to immunotherapy has raised the question of the reliability and reproducibility of its evaluation in lung biopsies compared with corresponding resected surgical specimens. Patients and methods PD-L1 expression in TC and IC was assessed in 160 patients with operable NSCLC on both whole surgical tissue sections and matched lung biopsies, by using a highly sensitive SP142 IHC assay. The specimens were scored as TC 0–3 and IC 0–3 based on increasing PD-L1 expression. Results PD-L1 expression was frequently discordant between surgical resected and matched biopsy specimens (the overall discordance rate=48%; 95% confidence interval 4.64–13.24) and κ value was equal to 0.218 (poor agreement). In all cases, the biopsy specimens underestimated the PD-L1 status observed on the whole tissue sample. PD-L1-positive IC tumors were more common than PD-L1-positive TC tumors on resected specimens. The discrepancies were mainly related to the lack of a PD-L1-positive IC component in matched biopsies. Conclusions Our results indicate relatively poor association of the PD-L1 expression in TC and IC between lung biopsies and corresponding resected tumors. Although these results need to be further validated in larger cohorts, they indicate that the daily routine evaluation of the PD-L1 expression in diagnostic biopsies can be misleading in defining the sensitivity to treatment with PD-L1 targeted therapy.

Background Expression of PD-L1 in tumor cells and tumor-infiltrating immune cells has been associated with improved efficacy to anti-PD-1/PD-L1 inhibitors in patients with advanced-stage non-small-cell lung cancer (NSCLC) and emerged as a potential biomarker for the selection of patients to cancer immunotherapies. We investigated the utility of circulating tumor cells (CTCs) and circulating white blood cells (WBCs) as a noninvasive method to evaluate PD-L1 status in advanced NSCLC patients. Patients and methods CTCs and circulating WBCs were enriched from peripheral blood samples (ISET® platform; Rarecells) from 106 NSCLC patients. PD-L1 expression on ISET filters and matched-tumor tissue was evaluated by automated immunostaining (SP142 antibody; Ventana), and quantified in tumor cells and WBCs. Results CTCs were detected in 80 (75%) patients, with levels ranging from 2 to 256 CTCs/4ml, and median of 60 CTCs/4ml. Among 71 evaluable samples with matched-tissue and CTCs, 6 patients (8%) showed ≥1 PD-L1-positive CTCs and 11 patients (15%) showed ≥1% PD-L1-positive tumor cells in tumor tissue with 93% concordance between tissue and CTCs (sensitivity = 55%; specificity=100%). From 74 samples with matched-tissue and circulating WBCs, 40 patients (54%) showed ≥1% PD-L1-positive immune infiltrates in tumor tissue and 39 patients (53%) showed ≥1% PD-L1 positive in circulating WBCs, with 80% concordance between blood and tissue (sensitivity = 82%; specificity=79%). We found a trend for worse survival in patients receiving first-line cisplatin-based chemotherapy treatments, whose tumors express PD-L1 in CTCs or immune cells (progression-free and overall survival), similar to the effects of PD-L1 expression in matched-patient tumors. Conclusions These results demonstrated that PD-L1 status in CTCs and circulating WBCs correlate with PD-L1 status in tumor tissue, revealing the potential of CTCs assessment as a noninvasive real-time biopsy to evaluate PD-L1 expression in patients with advanced-stage NSCLC.

The concept of personalized or stratified medicine in thoracic oncology have led to the development of companion diagnostic testing in the laboratories in order to detect genomic alterations which can be targeted by therapeutic molecules. The use of these companion tests has to be associated with an optimized quality control with the aim of getting solid results before treatment administration to the patients. The great majority of these tests is based on molecular biology approach. However, since the commercial availability of different antibodies targeting genomic alterations which can be used in formalin fixed paraffin sections, an alternative method to the molecular approach is the immunohistochemistry (IHC). Some of these antibodies are or will be probably soon used in a daily routine practice (such as anti-ALK or anti-MET antibodies). Other antibodies have currently a more restricted use in thoracic oncology (such as anti-BRAF V600E, anti-ROS1 and mutation-specific anti-EGFR antibodies). In this review, we aim to detail the advantages and the limits of IHC method in thoracic oncology field for personalized medicine, in particular comparatively to the molecular biology technology. Moreover, we discuss the opportunity to provide accredited IHC tests in the context of stratified medicine for lung cancer patients.

// Marius Ilie 1, 2, * , Edith Szafer-Glusman 3, * , Veronique Hofman 1, 2, 4 , Elodie Long-Mira 1, 2 , Rebecca Suttmann 3 , Walter Darbonne 3 , Catherine Butori 1 , Salome Lalvee 1 , Julien Fayada 4 , Eric Selva 4 , Wei Yu 3 , Charles-Hugo Marquette 5 , David S. Shames 3 , Elizabeth Punnoose 3 , Paul Hofman 1, 2, 4 1 Laboratory of Clinical and Experimental Pathology and Liquid Biopsy Laboratory, Pasteur Hospital, University Hospital Federation OncoAge, Universite Cote d’Azur, Nice, France 2 Institute for Research on Cancer and Ageing, Nice (IRCAN), INSERM U1081/UMR CNRS 7284, Team 3, Antoine Lacassagne Cancer Center, Nice, France 3 Department of Oncology Biomarker Development and Oncology Clinical Development, Genentech, Inc, South San Francisco, California, USA 4 Nice Hospital-Related Biobank (BB 0025-00033), Pasteur Hospital, Nice, France 5 Pneumology Department, Pasteur Hospital, Nice, France * These authors contributed equally to this work Correspondence to: Paul Hofman, email: hofman.p@chu-nice.fr Keywords: MET protein expression, circulating tumor cells, NSCLC, immunocytochemistry, targeted therapy Received: June 20, 2016 Accepted: January 28, 2017 Published: February 15, 2017 ABSTRACT Given the difficulty in obtaining adequate tissue in NSCLC, we investigated the utility of circulating tumor cells (CTCs) for MET status assessment in NSCLC patients. We used two platforms for CTC capture, and assessed MET expression in CTCs and matched-bronchial biopsies in patients with advanced-stage III/IV lung adenocarcinoma. Baseline peripheral blood was collected from 256 advanced-stage III/IV NSCLC patients from Genentech clinical trials, and from 106 patients with advanced-stage III/IV lung adenocarcinoma treated at the Department of Pneumology, Pasteur Hospital, Nice. CTCs were enriched using CellSearch (Genentech), or ISET technologies (Pasteur Hospital). MET expression was evaluated by immunofluorescence on CellSearch, and by immunocytochemistry on ISET-enriched CTCs and on matched FFPE tissue sections (Pasteur Hospital). CTCs were detected in 83 of 256 (32%) patients evaluated on CellSearch, with 30 samples (12%) exhibiting ≥ 5 CTCs/7.5 ml blood. On ISET, CTC were observed in 80 of 106 patients (75%), and 79 patients (75%) exhibited ≥ 5 CTCs/4 ml blood. MET expression on ISET CTCs was positive in 72% of cases, and the MET expression on matched-patient tissue was positive in 65% patients using the Onartuzumab IHC scoring algorithm (93% concordance). Quantification of MET expression using H-scores showed strong correlation between MET expression in tissue and CTCs (Spearman correlation, 0.93). MET status in CTCs isolated on ISET filters from blood samples of advanced-stage NSCLC patients correlated strongly with MET status in tumor tissue, illustrating the potential for using CTCs as a non-invasive, real-time biopsy to determine MET status of patients entering clinical trials.

Circulating tumors cells (CTCs) can be detected in the blood of metastatic melanoma patients (MMPs) both as isolated circulating tumor cells (iCTCs) and circulating tumor microemboli (CTMs), but their clinical significance remains unknown. The aim of this work was to evaluate the prognostic impact in metastatic cutaneous melanoma of CTMs and iCTCs identified by a cytomorphological approach using the isolation by size of tumor cell (ISET) method. We characterized the phenotype of CTCs using anti‐PS100, anti‐SOX10, anti‐CD10, and anti‐TRF2 antibodies. 128 MMPs and 37 control healthy individuals with benign nevi were included in this study. Results were compared to the follow‐up of patients. 109/128 (85%) MMPs showed CTCs, 44/128 (34%) with 2 to 6 CTMs and 65/128 (51%) with 4 to 9 iCTCs. PS100 expression was homogeneous in iCTCs and heterogeneous in CTMs. SOX10, CD10, and TRF2 were mainly expressed in CTMs. None of the control subjects demonstrated circulating malignant tumor cells. Overall survival was significantly decreased in patients with CTMs, independently of the therapeutic strategies. In conclusion, the presence of CTMs is an independent predictor of shorter survival from the time of diagnosis of MMPs.

Background: With the integration of various targeted therapies into the clinical management of patients with advanced lung adenocarcinoma, next-generation sequencing (NGS) has become the technology of choice and has led to an increase in simultaneously interrogated genes. However, the broader adoption of NGS for routine clinical practice is still hampered by sophisticated workflows, complex bioinformatics analysis and medical interpretation. Therefore, the performance of the novel QIAGEN GeneReader NGS system was compared to an in-house ISO-15189 certified Ion PGM NGS platform. Methods: Clinical samples from 90 patients (60 Retrospectively and 30 Prospectively) with lung adenocarcinoma were sequenced with both systems. Mutations were analyzed and EGFR, KRAS, BRAF, NRAS, ALK, PIK3CA and ERBB2 genes were compared and sampling time and suitability for clinical testing were assessed. Results: Both sequencing systems showed perfect concordance for the overlapping genes. Correlation of allele frequency was r2 = 0.93 for the retrospective patients and r2 = 0.81 for the prospective patients. Hands-on time and total run time were shorter using the PGM system, while the GeneReader platform provided good traceability and up-to-date interpretation of the results. Conclusion: We demonstrated the suitability of the GeneReader NGS system in routine practice in a clinical pathology laboratory setting.

Background: The overall prognosis of lung cancer patients remains dismal, in particular at advanced stages. Only complete surgical resection of early-stage tumors improves the prognosis of certain non-small cell lung cancer (NSCLC) patients. However, migration of circulating tumor cells (CTCs) into the blood stream is probably an early event of carcinogenesis inducing metastases. The fact that some of these CTCs could survive within this “liquid environment” suggest that they acquire phenotypic changes that would confer them improved resistance against anoikis. In this context, we looked if immune blood cells could transfer to CTCs some factors associated with this increased resistance. Materials and Methods: Lung cancer cells (A549 cell line) were incubated with different sub-population of blood cells (PBMCs, granulocytes, platelets) and serum to look for potential transfer of extracellular vesicles (EVs) into the cancer cells. To assess the inter-cell transfer we looked for the presence of a validated blood cell specific marker the miR-223 that should not be expressed in lung cancer cells. By using a direct method for CTCs detection and characterization, we looked for these biomarkers within CTCs of lung cancer patients with early and late stages. Moreover the quantification of these biomarkers was correlated with the expression of vimentin, cytokeratin and E-cadherin Results: First, A549 cells were able to quickly capture microRNA (in particular miR-223) within the control blood samples. We then identified neutrophils as a major source of these miRNA. The inter-cell transfer was EVs dependent and promoted improved resistance and survival of A549 cells cancer cells. In NSCLC patients with different stages, the presence of some specific miRNAs for blood cells was detected in a subpopulation of CTCs showing epithelial to mesenchymal phenotype, in particular an increase of vimentin expression and loss of E-cadherin expression. Conclusion: These results tend to prove that CTCs may capture extracellular vesicles from immune blood cells within the bloodstream and this phenomenon may be associated with a more aggressive phenotype. Inhibition of specific EVs transfer could be on interest for development of new targeted immunotherapies. Citation Format: Josephine Zangari, Marius Ilie, Simon Heeke, Véronique Hofman, Baharia Mograbi, Sophie Raynaud, Salome Lalvee, Nathalie Yazbeck, Charles-Hugo Marquette, Sylvie Leroy, Patrick Brest, Paul Hofman. Circulating lung tumor cells capture extracellular vesicles conferring resistance phenotype by the occurrence of epithelial-mesenchymal transition reprogramming [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 867. doi:10.1158/1538-7445.AM2017-867

Background: The activation of immune cells by immune checkpoint inhibitors showed promising results with increased patient survival in several types of cancer. Since no data exist for pulmonary basaloid squamous cell carcinoma (BSCC), we aimed to characterize the expression of PD-L1 and PD-1 as well as tumor infiltrating lymphocytes (TILs) in operable BSCC. Materials and Methods: We retrospectively included 57 patients with operable stages I-III BSCC. The expression of PD-L1 (clone SP142, Spring Bioscience), PD-1 (clone NAT105, Ventana) and CD8 (clone SP57, Ventana) was evaluated by automated immunohistochemical analysis in FFPE specimens of BSCC. PD-L1 expression was scored on tumor cells (TC3≥50% positive tumor cells; TC2≥5% but Results: PD-L1 expression on tumor cells (TC1-3) was observed in 30% of patients (17/57), with high-PD-L1 expressing TC (TC2/3) in 14% of cases (8/57). PD-L1 expression on tumor-infiltrating immune cells was noticed in 36% of patients (20/57), with high-PD-L1 expressing IC (IC2/3) in 18% of cases (10/57). PD-L1 expression strongly correlated with CD8+ TILs and PD-1+ expression. CD8+ TILs infiltrated the tumors in three different patterns (stromal, peritumoral, diffuse). High PD-L1 expression either on TC or IC was significantly associated with better progression-free survival (PFS) (TC0, P = 0.024; TC0/IC0, P = 0.03) and overall survival (OS) (TC0, P = 0.01; TC0/IC0, P = 0.007) in BSCC patients. High amounts of TILs and PD-1+ cells were significantly correlated with improved PFS (TILs, P = 0.035; PD-1+, P = 0.007) and OS (TILs, P = 0.016; PD-1+, P = 0.03). Conclusion: Increased PD-L1 TC and IC levels, TILs density and PD-1+ infiltrates are associated with better outcome in early-stage BSCC. Assessment of PD-L1 expression along with PD-1+ and CD8+ TILs could be useful to predict response to immune checkpoint inhibitors in BSCC. [M.I. and C.B. contributed equally to this work.] Citation Format: Marius Ilie, Catherine Butori, Véronique Hofman, Christelle Bonnetaud, Sandra Lassalle, Elodie Long, Salomé Lalvée, Nicolas Vénissac, Jérôme Mouroux, Charles Hugo Marquette, Paul Hofman. Distribution and prognostic relevance of PD-1/PD-L1 immune checkpoints and tumor-infiltrating lymphocytes in early-stage pulmonary basaloid squamous cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2218.

Background: Although small cell lung carcinomas (SCLC) show an initial response to treatment, patients rapidly suffer disease recurrence and become refractory to chemotherapy. Despite intensive research, the prognosis of SCLC remains poor, and therefore new strategies to improve outcome are urgently needed. Blockade of immune checkpoints PD-1/PD-L1 with monoclonal antibodies has recently emerged as a new therapeutic tool in oncology. Due to the difficulty in obtaining adequate tissue in diseases such as SCLC for PD-L1 expression assessment, we investigated the usefulness of circulating tumor cells (CTCs) detection as a non-invasive method to evaluate PD-L1 status in SCLC patients. Materials and Methods: CTC capture and PD-L1 expression was evaluated in a cohort of 18 SCLC patients for whom resected tissue specimens were available and were positive for CTCs, as detected by using the filtration-based ISET platform (Rarecells Diagnostics, Paris, France). PD-L1 expression was evaluated in ISET-captured CTCs and FFPE tissue sections by immunohistochemistry (IHC) using the SP142 rabbit monoclonal antibody (Spring Bioscience, USA). PD-L1 expression was scored on tumor cells (TC3≥50% positive tumor cells; TC2≥5% but Results: None of the SCLC cases showed PD-L1 protein expression in tumor cells on tissue specimens. PD-L1 expression was observed in the stroma. Using IHC assay, 67% of cases (8/12) were scored IC1-3 based on PD-L1 expression in tumor-infiltrating immune cells and 42% (5/12) were scored IC2/3. On the ISET platform, CTCs enumeration ranged from 3 to 637 CTCs/6 ml, with median 11 CTCs/6 ml, and clusters of CTCs in 83% of patients. No PD-L1 expression was observed in CTCs. However, 42% of cases showed PD-L1 expression in circulating immune cells, with PD-L1 status on filters being concordant with the IC2/3 status in patient-matched tumor tissue. Conclusion: PD-L1 seems expressed in only a fraction of SCLC, with carcinoma cells being negative in all cases, and PD-L1 expressed in tumor-infiltrating immune cells. Patients with stromal PD-L1 expression may potentially respond to anti-PD-1 treatment. Besides conventional IHC, ISET platform seems suitable for non-invasive real-time detection of circulating PD-L1 expression to determine PD-L1 status of SCLC patients entering clinical trials. Citation Format: Marius Ilie, Véronique Hofman, Elodie Long, Catherine Butori, Salomé Lalvée, Eric Selva, Nicolas Vénissac, Jérôme Mouroux, Charles Hugo Marquette, Paul Hofman. PD-L1 expression in primary tumor and circulating tumor cells in patients with small cell lung carcinomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2220.