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Ming Sound Tsao



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    MA 13 - New Insights of Diagnosis and Update of Treatment (ID 674)

    • Event: WCLC 2017
    • Type: Mini Oral
    • Track: Early Stage NSCLC
    • Presentations: 1
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      MA 13.02 - Comprehensive Genetic Analysis Related to  PD-L1 Expression in Early-stage Lung Squamous Cell Carcinoma (ID 9077)

      15:45 - 17:30  |  Author(s): Ming Sound Tsao

      • Abstract
      • Presentation
      • Slides

      Background:
      Recently, anti PD-1/PD-L1 immunotherapies have yielded promising outcomes in advanced squamous NSCLC. Several studies have suggested that tumor PD-L1 protein expression status might correlate with outcome and response to treatment. The aim of this study is to identify mRNA gene signatures and microRNAs associated with tumor PD-L1 expression in early-stage lung squamous cell carcinoma (SCC).

      Method:
      Early stage (I-II) SCC resected patient tumors were collected from 6 cancer centers as part of the SPECS II program. Gene expression profiling was performed on the specimens. PD-L1 protein expression was evaluated by immunohistochemistry on SCC FFPE tissue using the Dako 22C3 PD-L1 antibody. The tumor proportion score (TPS) for PD-L1 protein expression was compared with comprehensive clinicopathological, mRNA and miRNA data.

      Result:
      The prevalence of PD-L1 expression in this cohort of 255 Stage I-II SCC patients was 46.7% with a TPS cutoff of ≥ 1%, and 9.8% with a cutoff of ≥ 50%. Among 202 cases with available clinical and expression data, no significant association was observed between PD-L1 expression and clinical outcome. We identified a 12-gene signature from mRNA microarray using the Minimax Concave Penalty (MCP) regression method with an AUC of 0.92 at ≥ 5% TPS cutoff. A subset of 138 miRNAs was shown to be significantly differentially expressed between PD-L1 positive and PD-L1 negative groups at false discovery rate (FDR) of 0.05 with TPS cutoffs of ≥ 1%, ≥ 5% and ≥ 10%. No miRNAs were found to be significantly differentially expressed between the groups using a TPS cutoff of ≥ 50%. Gene Set Enrichment Analysis (GSEA) identified two pathways with gene sets that were significantly enriched (FDR < 0.05) in the PD-L1 negative group. No significant association was found between tumor mutation burden and PD-L1 expression level.

      Conclusion:
      PD-L1 expression prevalence is lower in early-stage lung SCC than in advanced NSCLC. No significant association was found between PD-L1 expression and prognosis in this cohort. Both mRNA gene signatures and miRNAs were identified to be predictive of PD-L1 expression. Through GSEA, two distinct gene sets were identified with expression correlated to PD-L1, one comprising genes related to ovary and another related to collagens and extracellular matrix (ECM). No significant association was found between tumor mutation burden and PD-L1 expression level. Following validation, these predictive signatures could be used to select patients with positive PD-L1 expression who may benefit from immunotherapy.

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    MA 14 - Diagnostic Radiology, Staging and Screening for Lung Cancer I (ID 672)

    • Event: WCLC 2017
    • Type: Mini Oral
    • Track: Radiology/Staging/Screening
    • Presentations: 1
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      MA 14.11 - Malignancy Risk Prediction of Pulmonary Nodule in Lung Cancer Screening – Diameter Or Volumetric Measurement  (ID 9113)

      15:45 - 17:30  |  Author(s): Ming Sound Tsao

      • Abstract
      • Presentation
      • Slides

      Background:
      Nodule size is an important parameter to determine malignancy risk. Semi-automated size measurements have the potential to replace manual measurements due to their higher accuracy and reproducibility, and less inter/intra-user variation. However, controversy exists regarding the relative accuracy of 2D diameter versus 3D volumetric measurement to predict malignancy risk. The objective of this study is to compare nodule malignancy prediction models based on 2D mean diameter versus volumetric measurement, both generated by a CAD Software.

      Method:
      We analyzed baseline LDCT reconstructed using high spatial frequency algorithm from 1746 participants (47% women, 53% men, age: 62.5 ± 5.8 yrs) in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan), who had ≥1 non-calcified nodules ≥3mm in diameter. CAD software (CIRRUS Lung Screening, Radboud University Medical Center, Nijmegen, the Netherlands) performed an automatic nodule segmentation, which could be optimised manually, measurement of mean diameter and volume was generated. Malignant or benign nodule status was confirmed by pathology or prolonged follow-up (median follow-up 5.5 years). Logistic regression models predicting cancer were prepared with one including mean diameter and the other including volume. The discrimination, the ability to classify cancer versus benign nodules correctly, was evaluated by the area under the receiver operator characteristic cure (AUC). The calibration - do predicted probabilities match observed probabilities, was assessed using Spiegelhalter’s z-test and graphically by plotting the observed and predicted mean probabilities of cancer by deciles of model risk.

      Result:
      There were in total 5878 nodules, including 119 cancers in 115 individuals. Both models gave similar predictive performances. AUC was 0.947 (95% CI 0.922-0.964) in the mean diameter model and 0.946 (95% CI 0.921-0.966) in the volumetric model (p=0.83). The calibrations were similar between the two models (figure). Figure 1



      Conclusion:
      The predictive performances of nodule malignancy prediction models using mean 2D nodule diameter and 3D volumetric data were indistinguishable.

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    MA 20 - Recent Advances in Pulmonology/Endoscopy (ID 685)

    • Event: WCLC 2017
    • Type: Mini Oral
    • Track: Pulmonology/Endoscopy
    • Presentations: 1
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      MA 20.11 - Chronic Obstructive Pulmonary Disease Prevalence in a Lung Cancer Screening Population (ID 9588)

      14:30 - 16:15  |  Author(s): Ming Sound Tsao

      • Abstract
      • Presentation
      • Slides

      Background:
      Chronic obstructive pulmonary disease (COPD) and lung cancer are associated through tobacco use. COPD is underdiagnosed in both the primary care and lung cancer populations. Diagnosis of COPD should lead to improved care and quality of life. Screening programs could provide an opportunity to capture undiagnosed COPD. We analyzed the Pan-Canadian Early Detection of Lung Cancer Study (PanCan Study) to evaluate the prevalence of COPD in a screening population.

      Method:
      The PanCan Study was a single arm lung cancer screening trial which recruited individuals to low dose CT scan, autofluorescence bronchoscopy, and biomarker screening. Eligible individuals were 50-75 years of age, had smoked within 15 years, and had a minimum six-year risk of lung cancer ≥ 2% based on a risk prediction model derived from PLCO study data, which included COPD as a risk factor. Consenting subjects completed a questionnaire including background medical conditions, high-risk work exposures, and smoking history. Baseline spirometry was performed, and COPD was defined by GOLD criteria. For individuals not receiving post-bronchodilator spirometry, COPD was defined as ‘probable’ if GOLD criteria were met pre-bronchodilator and there was no prior diagnosis of asthma. Individuals with definite or probable COPD were defined as having COPD.

      Result:
      Of 2537 individuals recruited, 2514 had available spirometry data. Mean age was 62.3 years, 55.3% were male, median pack-years smoked was 50, 62.3% were active smokers, 45.1% had symptoms of dyspnea, 52.4% cough, and 37.5% wheeze. 35.2% had worked in a high-risk occupation. Overall, 1136 (45.2%) met spirometry criteria for COPD. Of 1987 individuals without a prior history of COPD, 41.9% met spirometry criteria for COPD, of which 53.7% had moderate to severe disease. Of 527 individuals (21%) reporting a diagnosis of COPD at baseline, 57.5% met spirometry criteria for COPD, 32.2% did not, and 10.3% had a prior diagnosis of asthma. In a multivariate model for risk of COPD, age (odds ratio (OR)~per year~ 1.06), dyspnea (OR 1.42), being a current smoker (OR 1.43), and pack-years (log transformed OR 1.42) were significant (all p < 0.001) as were high-risk occupation (OR 1.24, p=0.013) and wheeze (OR 1.24, p = 0.024).

      Conclusion:
      A diagnosis of COPD by spirometry is common in a lung cancer screening trial population. Individuals with a pre-existing self-reported diagnosis of COPD often fail to meet spirometry criteria for their diagnosis. Testing a lung cancer screening population for COPD could significantly improve COPD diagnosis and treatment.

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    OA 15 - Diagnostic Radiology, Staging and Screening for Lung Cancer II (ID 684)

    • Event: WCLC 2017
    • Type: Oral
    • Track: Radiology/Staging/Screening
    • Presentations: 1
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      OA 15.01 - Lung Cancer Screening: Participant Selection by Risk Model – the Pan-Canadian Study (ID 8466)

      14:30 - 16:15  |  Author(s): Ming Sound Tsao

      • Abstract
      • Presentation
      • Slides

      Background:
      Retrospective studies indicate that selecting individuals for low dose computed tomography (LDCT) lung cancer screening based on a highly predictive risk model is superior to applying National Lung Screening Trial (NLST)-like criteria, which use only categorized age, pack-year and smoking quit-time information. The Pan-Canadian Early Detection of Lung Cancer Study (PanCan Study) was designed to prospectively evaluate whether individuals at high risk for lung cancer could be identified for screening using a risk prediction model. This paper describes the study design and results.

      Method:
      2537 individuals were recruited through 8 centers across Canada based on a ≥2% of lung cancer risk estimated by the PanCan model, a precursor to the validated PLCOm2012 model. Individuals were screened at baseline and 1 and 4 years post-baseline.

      Result:
      At a median 5.5 years of follow-up, 164 individuals (6.5%) were diagnosed with 172 lung cancers. This was a significantly greater percentage of persons diagnosed with lung cancers than was observed in the NLST(4.0%)(p<0·001). Compared to 57% observed in the NLST, 77% of lung cancers in the PanCan Study were early stage (I or II) (p<0.001) and to 25% in a comparable population, age 50-75 during 2007-2009 in Ontario, Canada’s largest province, (p<0·001).

      Conclusion:
      Enrolling high-risk individuals into a LDCT screening study or program using a highly predictive risk model, is efficient in identifying individuals who will be diagnosed with lung cancer and is compatible with a strong stage shift – identifying a high proportion at early, potentially curable stage. Funding This study was funded by the Terry Fox Research Institute and Canadian Partnership Against Cancer. ClinicalTrials.gov number, NCT00751660

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    P1.02 - Biology/Pathology (ID 614)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P1.02-016 - Establishment of Lung Adenocarcinoma Organoid Cultures (ID 9386)

      09:30 - 16:00  |  Author(s): Ming Sound Tsao

      • Abstract

      Background:
      Effective non immune- oncology targeted therapies are available only for less than 25% (non-Asian) and 60% (East Asian) of lung adenocarcinoma (ADC) patients. ADC has one of the largest burdens of genetic abnormalities among all cancers. It is understood that ADC arise from the accumulation of abnormalities which dysregulate key cellular processes to permit a growth and survival. Further improvement in our ability to develop novel therapies requires additional lung cancer models that closer mimic the genetic alterations found in patient tumors. Three-dimensional organoid culture (“mini organs”) of tumor cells recently has generated great interest as such a novel preclinical model.

      Method:
      We experimented to develop novel media formulation to generate organoid models from 10 established ADC cell lines, 7 primary culture ADC cell lines developed from patient-derived xenograft (PDX) models, 8 ADC PDX models, and 20 resected patient ADC tissues. Organoid cultures that could be serially passaged for at least 5 passages were defined as long-term organoid models. Organoids were characterized for their histopathological features and immunomarker expression (p40, TTF-1, p53), growth rate and drug sensitivities.

      Result:
      Long-term organoid cultures were developed from 9/10 (90%) of established ADC cell lines, 3/7 (42%) of PDX-derived cell lines, 2/8 (25%) of ADC PDX models, and 1/20 (5%) of primary patient ADC tissues. Established organoid cultures recapitulated the histological features of ADC. We are currently collecting the data on growth rates and drug sensitivities of selected organoid cultures.

      Conclusion:
      Lung adenocarcinoma organoid cultures can be established for both established cell lines and patient tumor tissues but with variable success rates. Further studies are necessary to understand the discrepancy in the establishment rates from different sources of the tumor cells.

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    P1.07 - Immunology and Immunotherapy (ID 693)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Immunology and Immunotherapy
    • Presentations: 1
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      P1.07-022 - Routine PD-L1 Immunohistochemistry Testing by 22C3 in a Canadian Reference Testing Centre (ID 9487)

      09:30 - 16:00  |  Presenting Author(s): Ming Sound Tsao

      • Abstract
      • Slides

      Background:
      Immunohistochemical testing for PD-L1 expression is increasingly used as a predictive biomarker for anti PD-1/PD-L1 immunotherapies in non-small cell lung cancer (NSCLC). We report here the experience of population-based PD-L1 testing using the 22C3 antibody in the routine clinical practice of a large regional reference pathology laboratory.

      Method:
      PD-L1 testing was performed by the PD-L1 immunohistochemistry (IHC) 22C3 PharmDx assay (Agilent) using a Dako Link48 autostainer, according to the manufacturer’s instructions. Testing was performed on (1) all biopsies and resections for NSCLC performed at University Health Network (UHN) and partner hospitals between August 1, 2016 and March 31, 2017; (2) all cases of NSCLC referred from external sources for EGFR/ALK testing; and (3) cases of pulmonary squamous cell carcinoma referred in specifically for PD-L1 testing. PD-L1 IHC was also performed retroactively on archived UHN cases upon request by oncologists, dating from January 1, 2013. Tumour Proportion Scores (TPS) were reported in three categories (no expression, <1%; low expression, 1-49%; and high expression, ≥50%).

      Result:
      A total of 2027 PD-L1 IHC were performed on specimens from 1814 patients, of which 110 (5.4%) were reported as indeterminate, mostly due to insufficient tumor cellularity. Indeterminate results were more frequent in biopsy (6.4%) vs. resection (2.7%) specimens. For the remaining 1917 evaluable tests, proportions in each TPS category were: <1% (42.3%); 1-49% (28.5%); ≥50% (29.3%). In 1482 tests with known EGFR mutation status, EGFR-mutated tumors (n=296) demonstrated lower rates of PD-L1 expression [TPS <1% (51.7%); 1-49% (29.4%); ≥50% (18.9%); P<0.01]. No statistically significant difference in PD-L1 expression was detected in ALK-rearranged tumors (n=29). Of 100 patients with successful PD-L1 staining in both a biopsy and paired resection specimen, 57/100 (57%) demonstrated concordant TPS categories in both specimens. Only 22/49 (44.9%) biopsies with TPS<1% showed TPS<1% in the resection, while 26/49 (53.1%) and 1/49 (2.0%) showed TPS 1-49% and ≥50%, respectively. Of biopsies with TPS 1-49%, 17/29 (58.6%) were concordant in the resection, while 5/29 (17.2%) and 7/29 (24.1%) showed TPS <1% and ≥50%, respectively. Among biopsies with TPS≥50%, 18/22 (81.8%) were concordant in the resection, while 4/22 (18.2%) showed TPS 1-49% in the resection.

      Conclusion:
      In our population-based study, PD-L1 expression in NSCLC using the 22C3 antibody demonstrated similar prevalence as reported in clinical trials. EGFR mutated but not ALK rearranged tumors were associated with lower PD-L1 expression. Intra-tumoral heterogeneity of PD-L1 expression may result in its under-estimation in biopsy specimens compared to paired resection specimens.

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    P3.01 - Advanced NSCLC (ID 621)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Advanced NSCLC
    • Presentations: 2
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      P3.01-019 - Canadian Multicentre Validation Study of Plasma Circulating Tumour DNA for Epidermal Growth Factor (EGFR) T790M Testing (ID 8878)

      09:30 - 16:00  |  Presenting Author(s): Ming Sound Tsao

      • Abstract
      • Slides

      Background:
      Plasma detection of EGFR T790M mutations in circulating tumour DNA (ctDNA) of advanced lung cancer patients with acquired resistance to EGFR tyrosine kinase inhibitor (TKI) has been proposed as alternative to tumor re-biopsy. This national validation study across Canadian centres aimed to establish the sensitivity and specificity of plasma detection of T790M as a clinical test using digital droplet (dd)PCR and next generation sequencing (NGS) assays.

      Method:
      Canadian patients at 7 centres undergoing screening for ASTRIS (NCT02474355) were invited to participate in this companion blood-based study. Patients with acquired resistance to EGFR TKI consented to collection of blood samples and demographic data. Samples were analysed using ddPCR and/or NGS platforms available at 4 molecular diagnostic laboratories across Canada. Concordance between the results of plasma T790M assayed in these 4 laboratories with reference tissue/plasma testing conducted for ASTRIS was assessed.

      Result:
      63 patients participated; the median age was 64 years (range 31-87), 69%(40/58) were Asian; 55%(33/60) were male. All patients received prior EGFR TKI, 17%(10/60) also received prior chemotherapy. Reference testing for EGFR T790M for ASTRIS eligibility identified positive T790M(+) results for 31(49%), negative(-) for 30(48%) and indeterminate(i) results for 2(3%) patients. One laboratory tested all 63 patient samples using both ddPCR and NGS (Oncomine Lung cfDNA assay), another laboratory tested 18 samples using ddPCR and NextSeq, a third tested 10 samples using ddPCR and COBAS EGFRv2, and a fourth tested 6 samples using Ion Torrent PGM. A total of 188 tests were performed including 91 by ddPCR, 87 NGS and 10 COBAS assays. Combining test results for each patient, 60%(38/63) of patient plasma samples were T790M+, 23(37%) were T790M-, and 2(3%) were inconclusive. Of 31 patients with reference T790M+ results from ASTRIS, 23(74%) had T790M detected in plasma, 6(19%) did not (T790M-), and 2(7%) had indeterminate (T790Mi) plasma results. For 30 patients with T790M- reference results from ASTRIS, 13(43%) had plasma T790M+ and 17 plasma T790M- results. The 2 patients with T790Mi by reference testing both had T790M+ results from plasma. Altogether, 47%(15/32) of patients deemed to have T790M-/i tumours by reference testing were found to have T790M+ results by plasma in this multicentre study. Combining results from both tissue and plasma testing, 73%(46/63) of study patients had T790M+ results.

      Conclusion:
      Plasma ctDNA testing in this multicentre Canadian study identified a significant number of additional patients eligible for osimertinib therapy beyond routine biopsy tissue testing for EGFR T790M.

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      P3.01-062 - The Perceived Value of Avoiding Biopsy: Patients' Willingness to Pay for Circulating Tumour DNA T790M Testing (ID 10004)

      09:30 - 16:00  |  Author(s): Ming Sound Tsao

      • Abstract
      • Slides

      Background:
      Plasma detection of circulating tumour DNA (ctDNA) with T790M mutation in the context of EGFR tyrosine kinase resistance has been shown to have high concordance with tissue biopsy specimens. In a public healthcare system, patients’ perceived value of a test and willingness to pay can inform policy decisions regarding implementation and funding of a novel technology.

      Method:
      As part of screening for the ASTRIS clinical trial (NCT02474355), Canadian patients were invited to participate in a national validation study of blood-based ctDNA T790M testing. Eligible patients had acquired resistance to EGFR TKI and consented to collection of blood samples, demographic data, and completion of a structured interview measuring their perceived value of blood-based ctDNA testing as an alternative to tumour biopsy. They were asked about their willingness to pay for testing using both open-ended and iterative bidding approaches. The study was supported by a grant from AstraZeneca.

      Result:
      60 patients were accrued to the study. Median age of the cohort is 64 years (range 31-87); 69% are Asian (40/58); 55% (33/60) are male. All patients had received prior EGFR kinase inhibitor treatment, with 67% (45/60) receiving gefitinib. 17% of patients also received chemotherapy (10/60). A median of 1 prior line of therapy had been received (range 1-6). All patients preferred to have the blood test over repeat tumour biopsy. Patients estimated a mean reasonable price to pay for the test of $954; median $300 (range 0-10,000; IQR 150-800). Patients were personally willing to pay a mean of $281; median $100 (range 0-2500; IQR 33-350).

      Conclusion:
      In a public health system that covers the cost of standard diagnostic tests, Canadian patients indicated a willingness to pay out of pocket for peripheral blood detection of ctT790M. Patients have high perceived value of ctDNA and prefer it to tumor biopsy.

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    P3.02 - Biology/Pathology (ID 620)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P3.02-097c - Detection of the EGFR P.(T790M) Mutation by Different Methods: A Small Comparison Case Study (ID 10260)

      09:30 - 16:00  |  Author(s): Ming Sound Tsao

      • Abstract

      Background:
      About 50-60% of non-small cell lung cancer (NSCLC) patients with a Tyrosine Kinase Inhibitor (TKI) sensitizing EGFR mutation can develop therapy resistance via the acquisition of the additional p.(T790M) mutation. The identification of this group of patients is important because they can be treated with a 3[rd] line TKI: Osimertinib. Analysis of plasma samples has become a minimally invasive alternative to repeat tissue biopsy for the detection of the EGFR p.(T790M) mutation. The mutation can be detected in plasma and tissue by various methods including the FDA approved Roche COBAS® EGFR v2 test, the EntroGen® EGFR test and digital droplet PCR (ddPCR). In this study, we compared the detection of the EGFR p.(T790M) mutation by ddPCR and COBAS in plasma specimens, and ddPCR and EntroGen in tissue specimens.

      Method:
      Blood from 14 NSCLC was collected in STRECK™ blood collection tubes. Plasma was prepared and circulating cell-free (ccf) DNA extracted with the COBAS and Qiagen method. DNA was analyzed for the presence of the EGFR TKI sensitizing and p.(T790M) mutation by COBAS, or the p.(T790M) mutation only by ddPCR on a Biorad QX200 platform. In addition, 26 biopsies from EGFR-positive patients who progressed on TKI, and which were tested p.(T790M) negative by Entrogen were re-analyzed by ddPCR.

      Result:
      Nine out of fourteen plasma samples were found to contain DNA with the sensitizing EGFR mutation by COBAS. The p.(T790M) mutation was found in four of these nine cases. ddPCR revealed one additional p.(T790M)-positive plasma sample that was tested negative by COBAS. ddPCR detected ten p.(T790M)-positive cases in the 26 EntroGen p.(T790M) negative samples, and suggests a 38% of false negative rate of the EntroGen method in this small cohort of samples.

      Conclusion:
      ddPCR for the detection of the EGFR p.(T790M) mutation in plasma and tissue appears to be associated with a higher sensitivity compared to the COBAS and EntroGen methods, respectively.

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    P3.03 - Chemotherapy/Targeted Therapy (ID 719)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Chemotherapy/Targeted Therapy
    • Presentations: 1
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      P3.03-008 - Organoid Cultures of Lung Squamous Cell Carcinoma for Drug Screening (ID 8481)

      09:30 - 16:00  |  Author(s): Ming Sound Tsao

      • Abstract

      Background:
      The difficulty of establishing lung squamous cell carcinoma (LUSC) derived cell lines have posed significant challenges for identifying potential therapeutic targets and understanding the complexity of this disease. We have previously developed a LUSC patient-derived xenograft (PDX) platform in which over 50 models have been characterized on the genomic and transcriptomic level. We describe a method to culture and establish LUSC organoids from PDX models and demonstrate their utility for drug testing.

      Method:
      Surgically resected LUSC were implanted into the subcutaneous flank of NOD/SCID mice to establish PDXs. To generate organoids, PDX tissue was dissociated into single cells using Liberase and TypLE and plated in growth factor reduced matrigel dome with media overlay. Organoids were processed for histological and immunohistochemical marker characterization. Organoids and matched PDX were subjected to shallow next generation sequencing for mutation and copy number analysis. Drug screening was performed in 384 well plates and viability was determined by Celltiter Glo 3D assay.

      Result:
      Of the 17 LUSC PDX models attempted, organoid lines from 3 PDX models were propagated beyond 20 passages for over 100 days. The success rate of organoid establishment is 18%, which is higher than establishing LUSC cell lines. Organoids exhibited various doubling rates ranging from 38 to 48 hours. Organoid tumor cells faithfully recapitulated the immuno-phenotypes of the matched PDX, expressing p63 and CK5/6 and were EpCAM positive and H2K negative by flow cytometry analysis. Organoids implanted in NOD/SCID mice formed tumors that reflected the histology of the matched PDX. Shallow sequencing revealed similar copy number status between the organoid and matched PDX. RNA sequencing analysis is pending and will be reported. Organoids were amenable for drug testing and exhibited varying sensitivities to the PI3K inhibitors BKM120 and BYL719 based on each model’s PI3K pathway status.

      Conclusion:
      We describe a method of developing LUSC PDX-derived organoids that can be propagated long term and faithfully recapitulate the histological and molecular characteristics of the original tumor. Additionally, we demonstrate their utility for in vitro drug testing. Organoids may be useful for preclinical modeling and therapeutic evaluation of LUSC.

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    PL 03 - Immunology in Lung Cancer Update 2017 (ID 584)

    • Event: WCLC 2017
    • Type: Plenary Session
    • Track: Immunology and Immunotherapy
    • Presentations: 1
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      PL 03.03 - Blueprint 2: PD-L1 Immunohistochemistry Comparability Study in Real-Life, Clinical Samples (ID 7836)

      08:15 - 09:45  |  Presenting Author(s): Ming Sound Tsao

      • Abstract
      • Presentation
      • Slides

      Abstract:
      PD-L1 immunohistochemistry (IHC) has been established as companion or complementary diagnostic assays, each having been developed as a predictive biomarker for specific anti-PD-1/PD-L1 immunotherapies.[1] The Blueprint phase 1 was conducted as a feasibility study to assess the staining (analytical) comparability of four PD-L1 IHC assays (22C3, 28-8, SP142, and SP263) that were developed for their respective immune checkpoint inhibitor therapies.[2] Without correlation with treatment outcome, the study also assessed the putative diagnostic performance of these assays through comparisons of PD-L1 status classification above and below selected expression cutoffs associated with the clinical use of various assays. Serial sections from paraffin blocks of 39 resected non-small cell lung cancers (NSCLC) were stained using assays that were used in the clinical trials, and three experts in interpreting the four respective assays independently assessed the percentages of tumor and immune cells staining positive at any intensity. The results demonstrated that three PD-L1 assays (28-8, 22C3, SP263) showed comparable analytical performance for assessment of PD-L1 expression on tumor cells, while the SP-142 PD-L1 assay appeared to stain less tumor cells compared to the other assays.[2] In contrast, all assays stained tumor infiltrating immune cells, but with poor concordance between assays. The phase 1 study had several limitations: (1) samples were obtained from a commercial source and did not necessarily reflect the real-world samples tested clinically, and (2) the number of pathologists involved in the scoring was small. In addition, a fifth PD-L1 assay (73-10) has since been developed as a potential biomarker for avelumab (EMD Serono/Merck KGaA/Pfizer). The goals of Blueprint phase 2 are: (1) to validate the assay comparability results obtained in Blueprint phase 1 study using real world clinical lung cancer samples and all five clinically used PD-L1 assays (28-8, 22C3, SP142, SP263, and 73-10), (2) to assess the comparability and heterogeneity of PD-L1 assay results in surgical tumor resection, core needle and FNA samples prepared from same tumor, and (3) to assess the concordance of PD-L1 scoring by pathologists from around the world using standard light microscopy vs. digital images accessed by a web-based system. In blueprint phase 2A, 18 participating pathologists, with respective institutional research ethics board approval, contributed unstained serial sections from altogether 81 lung cancer cases that came through routine clinical practice. These included 40 adenocarcinomas, 25 squamous cell carcinomas, 5 poorly differentiated non-small cell carcinoma and 11 small cell carcinomas. The cases included resected tumor (n=20), core/bronchial biopsies (n=20), tumor positive lymph node biopsy/resection (n=20) and cytology cell block (n=21) samples. In blueprint phase 2B, 9 pathologists prepared from 30 freshly resected NSCLC specimens, paraffin blocks of matched resection, core needle and fine needle aspiration samples. Each slide set of 81 cases from phase 2A were stained with the FDA-cleared (28-8, 22C3, SP142) or clinical trial (SP263 and 73-10) PD-L1 assays, in a CLIA-approved immunohistochemistry laboratory. The slides were scored by 24 experienced pulmonary pathologists (IASLC Pathology committee Blueprint phase 2 members),[4] all having received group training on scoring the PD-L1 IHC on tumor and immune cells. PD-L1 stained tumor cells were scored as continuous number (0% to 100%), and placed into 1 of 7 categories (<1%, 1-4%, 5-9%, 10-24%, 25-49%, 50-79%, 80-100%). These categories represent cut-offs that have been used in various immune checkpoint inhibitor trials. All assays were also scored for immune cell PD-L1 staining based on the scoring system developed for the SP-142 assay. As only one set of glass slides is available for each assay, each pathologist was randomly assigned to conduct the scoring using microscope (2 glass assays) or by web-based digital images (3 digital assays). The inter-assay concordance of PD-L1 staining on tumor cells and tumor infiltrating immune cells will be assessed using the mean scores from all pathologists. The large sample size scores should provide more reliable data on their analytical comparability. Inter-pathologist concordance results should provide evidence on reliability of scoring with different cut-points. Importantly, the above concordance results across different sample types should also provide insights on potential variability and feasibility in PD-L1 scoring across different sample types, especially cytology samples. This may then allow for a broad implementation strategy on PD-L1 testing in clinical practice. The results of phase 2A will be presented at the meeting.IASLC Pathology Committee Blueprint phase 2 members: Mary-Beth Beasley, Alain Borczuk, Johan Botling, Lukas Bubendorf, Gang Chen, Lucian Chirieac, Teh-Ying Chou, Jin-Haeng Chung, Sanja Dacic, Fred R. Hirsch, Keith M. Kerr, Mari Mino-Kenudson, Sylvie Lantuejoul, Andre Moreira, Andrew Nicholson, Masayuki Noguchi, Guiseppe Pelosi, Claudia Poleri, Prudence Russell, Jennifer Sauter, Erik Thunnissen, William D. Travis, Ming S. Tsao, Ignacio Wistuba, Murry Wynes, Yasushi Yatabe, Hui Yu. References: IASLC ATLAS of PD-L1 Immunohistochemistry Testing in Lung Cancer. M.S.Tsao, K.M. Kerr, Y. Yatabe, S. Dacic, F.R. Hirsch (Editors), International Association for Study of Lung Cancer (IASLC) Press, 2017 Hirsch FR, McElhinny A, Stanforth D, et al. PD-L1 Immunohistochemistry Assays for Lung Cancer: Results from Phase 1 of the "Blueprint PD-L1 IHC Assay Comparison Project". J Thorac Oncol. 2017 Feb;12(2):208-222. Feng Z, Schlichting M, Helwig C, et al. Comparative study of two PD-L1 expression assays in patients with non-small cell lung cancer (NSCLC). J Clin Oncol 35, 2017 (suppl; abstr e20581)

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