Tumor Material Research Articles

Non-Invasive Prediction of IDH Mutation in Patients with Glioma WHO II/III/IV Based on F-18-FET PET-Guided In Vivo 1H-Magnetic Resonance Spectroscopy and Machine Learning.

Simple SummaryApproximately 75–80% of according to the classification of world health organization (WHO) grade II and III gliomas are characterized by a mutation of the isocitrate dehydrogenase (IDH) enzymes, which are very important in glioma cell metabolism. Patients with IDH mutated glioma have a significantly better prognosis than patients with IDH wildtype status, typically seen in glioblastoma WHO grade IV. Here we used a prospective O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) positron emission tomography guided single-voxel 1H-magnetic resonance spectroscopy approach to predict the IDH status before surgery. Finally, 34 patients were included in this neuroimaging study, of whom eight had additionally tissue analysis. Using a machine learning technique, we predicted IDH status with an accuracy of 88.2%, a sensitivity of 95.5% and a specificity of 75.0%. It was newly recognized, that two metabolites (myo-inositol and glycine) have a particularly important role in the determination of the IDH status.Isocitrate dehydrogenase (IDH)-1 mutation is an important prognostic factor and a potential therapeutic target in glioma. Immunohistological and molecular diagnosis of IDH mutation status is invasive. To avoid tumor biopsy, dedicated spectroscopic techniques have been proposed to detect D-2-hydroxyglutarate (2-HG), the main metabolite of IDH, directly in vivo. However, these methods are technically challenging and not broadly available. Therefore, we explored the use of machine learning for the non-invasive, inexpensive and fast diagnosis of IDH status in standard 1H-magnetic resonance spectroscopy (1H-MRS). To this end, 30 of 34 consecutive patients with known or suspected glioma WHO grade II-IV were subjected to metabolic positron emission tomography (PET) imaging with O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) for optimized voxel placement in 1H-MRS. Routine 1H-magnetic resonance (1H-MR) spectra of tumor and contralateral healthy brain regions were acquired on a 3 Tesla magnetic resonance (3T-MR) scanner, prior to surgical tumor resection and molecular analysis of IDH status. Since 2-HG spectral signals were too overlapped for reliable discrimination of IDH mutated (IDHmut) and IDH wild-type (IDHwt) glioma, we used a nested cross-validation approach, whereby we trained a linear support vector machine (SVM) on the complete spectral information of the 1H-MRS data to predict IDH status. Using this approach, we predicted IDH status with an accuracy of 88.2%, a sensitivity of 95.5% (95% CI, 77.2–99.9%) and a specificity of 75.0% (95% CI, 42.9–94.5%), respectively. The area under the curve (AUC) amounted to 0.83. Subsequent ex vivo 1H-nuclear magnetic resonance (1H-NMR) measurements performed on metabolite extracts of resected tumor material (eight specimens) revealed myo-inositol (M-ins) and glycine (Gly) to be the major discriminators of IDH status. We conclude that our approach allows a reliable, non-invasive, fast and cost-effective prediction of IDH status in a standard clinical setting.

Autologous Vs. Allogeneic Stem Cell Transplantation in Double-Expressor Lymphoma

Purpose: Dual expression of MYC and BCL2 proteins (Double Expressor Lymphoma-[DEL]) is an important prognostic factor in patients (pts) with diffuse large B-cell lymphoma (DLBCL) who are treated with standard chemo-immunotherapy. Studies have suggested that pts with these biomarkers have inferior survival compared to pts who were non-DEL after autologous stem cell transplantation (autoSCT). For this reason, allogeneic stem cell transplantation (alloSCT) has been advocated for its potential graft-versus-lymphoma effect. Data are limited however regarding the outcomes in pts with relapsed DEL who were treated with autoSCT vs. alloSCT. Methods: Data from pts with relapsed DEL/DLBCL who underwent auto- and alloSCT as their first transplant at our center and in whom archived tumor material was available were analyzed. Cutoff values of 40% for MYC and 70% for BCL2 were established by immunohistochemistry (IHC). The majority of autoSCT pts (84%) underwent chemo-mobilization of stem cells with rituximab (R) for in-vivo purging; rituximab was also given on days+1 and +8 with BEAM conditioning (J Clin Oncol 2005; 23:2240-7; Clin Cancer Res 2018; 24:2304-11). Conditioning for the alloSCT was myeloablative (n=16, 50%), reduced-intensity (n=6, 19%), and nonmyelablative (n=10,31%). The study was IRB-approved at our center. Kaplan-Meier analysis and corresponding log-rank/Gray's tests were used to estimate and compare overall survival (OS), progression-free survival (PFS), and cumulative incidence (CI) of non-relapse mortality and relapse by SCT group. Standard multivariable Cox regression was used to evaluate associations between SCT type and OS/PFS after controlling for differences in baseline characteristics and cause-specific multivariable Cox regression was used for competing-risk outcomes [non-relapse mortality (NRM) and relapse]. Results: The study included 161 autoSCT and 32 alloSCT pts treated between 2000-2018. Median age was 59 (range,18-80) and 55 years (range, 21-66), respectively (P=0.009). Male gender was 62.7 vs 50.0%, respectively (P= 0.234). Fifty-one (32.5%) autoSCT pts and 9 (28.1%) alloSCT pts had an elevated serum LDH (P= 0.683) and 41/148 (27.7%) autoSCT and 11/25 (44.0%) alloSCT pts were PET-positive at study entry (P=0.106). The time from diagnosis to transplant was 20.0 and 25.2 months, respectively, (P=0.068), and the distribution of the years of transplant was similar between both groups (P=0.317). Significant differences between treatment groups were observed for prior number of chemotherapies, disease status, stage, and HCT-CI score at transplant. Pts. receiving alloSCT were more heavily pretreated [median 3 prior therapies, (range 1-8) vs. a median of 2, (range 1-6); P=0.0001], had more advanced stage III-IV disease (P=0.035), and more refractory disease (P=0.010) at transplant. In addition, a higher percentage of alloSCT pts had an HCT-CI of >4 (28.1% vs. 10.2%, P=0.018) at study entry. Allogeneic transplant characteristics included matched siblings (n=18; 56.3%), matched unrelated (n=13, 40.6%) and haplo-identical (n=1, 3.1%) donors. With a median follow-up for autoSCT surviving pts of 65 months (range, 5-217 months) and 93 months (range, 34--124 months) for alloSCT pts, the OS at 5-years were 59% and 34%, respectively (P= 0.0001) (Figure1). The PFS rates at 5-years were 49% and 31%, respectively (P = 0.002). AutoSCT had a similar rate of relapse to alloSCT but a lower rate of NRM. The 5-year CI of relapse was 37% vs 28%, respectively (P = 0.611) and the 5-year NRM rates were 14% vs 41 % (P=0.0001), respectively (Figure 2). The associations between SCT group and outcomes persisted after adjusting for differences between groups (alloSCT vs. autoSCT HR= 3.46/p=0.0004 for OS; HR=2.67/p=0.005 for PFS; HR=4.74/p=0.009 for NRM; HR=2.22/p=0.080 for relapse). The 100-day CI of grade II-IV and III-IV acute GVHD in the alloSCT group was 37.5 and 9.4%, respectively. The 1-year CI of chronic GVHD was 25.0%. C onclusions: This study is the first to show that autoSCT confers a superior survival in pts with relapsed DEL/DLBCL compared to alloSCT. Our conclusions are supported by long-term follow-up. The use of novel nonmyeloablative regimens in a larger number of pts receiving an alloSCT and ongoing studies at our center with targeted investigational agents after autoSCT may improve results. Disclosures Khouri: Pfizer: Research Funding; Bristol Myers Squibb: Research Funding. Iyer:CRISPR: Research Funding; Spectrum: Research Funding; Daiichi Sankyo: Consultancy; Trillium: Research Funding; Curio Biosciences: Honoraria; Target Oncology: Honoraria; Afffimed: Research Funding; Merck: Research Funding; Legend Biotech: Consultancy; Rhizen: Research Funding; Seattle Genetics, Inc.: Research Funding. Popat:Bayer: Research Funding; Novartis: Research Funding. Qazilbash:Angiocrine: Research Funding; Amgen: Research Funding; Bioclinica: Consultancy; Janssen: Research Funding; Bioline: Research Funding. Champlin:DKMS America: Membership on an entity's Board of Directors or advisory committees; Actinium: Consultancy; Johnson and Johnson: Consultancy; Omeros: Consultancy; Cytonus: Consultancy; Takeda: Patents & Royalties; Genzyme: Speakers Bureau.

Biomarker testing in non-small cell lung cancer in routine care: Analysis of the first 3,717 patients in the German prospective, observational, nation-wide CRISP Registry (AIO-TRK-0315)

ObjectivesAn increasing number of treatment-determining biomarkers has been identified in non-small cell lung cancer (NSCLC) and molecular testing is recommended to enable optimal individualized treatment. However, data on implementation of these recommendations in the “real-world” setting are scarce. This study presents comprehensive details on the frequency, methodology and results of biomarker testing of advanced NSCLC in Germany. Patients and methodsThis analysis included 3,717 patients with advanced NSCLC (2,921 non-squamous; 796 squamous), recruited into the CRISP registry at start of systemic therapy by 150 German sites between December 2015 and June 2019. Evaluated were the molecular biomarkers EGFR, ALK, ROS1, BRAF, KRAS, MET, TP53, RET, HER2, as well as expression of PD-L1. ResultsIn total, 90.5 % of the patients were tested for biomarkers. Testing rates were 92.2 % (non-squamous), 70.7 % (squamous) and increased from 83.2 % in 2015/16 to 94.2% in 2019. Overall testing rates for EGFR, ALK, ROS1, and BRAF were 72.5 %, 74.5 %, 66.1 %, and 53.0 %, respectively (non-squamous). Testing rates for PD-L1 expression were 64.5 % (non-squamous), and 58.5 % (squamous). The most common testing methods were immunohistochemistry (68.5 % non-squamous, 58.3 % squamous), and next-generation sequencing (38.7 % non-squamous, 14.4 % squamous). Reasons for not testing were insufficient tumor material or lack of guideline recommendations (squamous). No alteration was found in 37.8 % (non-squamous), and 57.9 % (squamous), respectively. Most common alterations in non-squamous tumors (all patients/all patients tested for the respective biomarker): KRAS (17.3 %/39.2 %), TP53 (14.1 %/51.4 %), and EGFR (11.0 %/15.1 %); in squamous tumors: TP53 (7.0 %/69.1 %), MET (1.5 %/11.1 %), and EGFR (1.1 %/4.4 %). Median PFS (non-squamous) was 8.7 months (95 % CI 7.4–10.4) with druggable EGFR mutation, and 8.0 months (95 % CI 3.9–9.2) with druggable ALK alterations. ConclusionTesting rates in Germany are high nationwide and acceptable in international comparison, but still leave out a significant portion of patients, who could potentially benefit. Thus, specific measures are needed to increase implementation.

Prognostic and Monitoring Value of Circulating Tumor Cells in Adrenocortical Carcinoma: A Preliminary Monocentric Study.

Simple SummaryCarcinoma of the cortical region of the adrenal (ACC) is a rare and aggressive cancer often with poor prognosis and limited therapies. For these reasons, tumor markers for early diagnosis and monitoring the therapy and tumor evolution are required. This paper demonstrates in a cohort of 19 patients affected by ACC, that in a simple blood draw (liquid biopsy), different cells associated with the tumor can be found in samples taken before and after surgery. Among them, the number of circulating tumor cells in blood samples taken before surgery can be predictive of the patients’ survival and tumor recurrence, thus contributing valuable information on the tumor, which may contribute to improve patient management and follow up. Further studies on larger cohorts of ACC patients are required to validate this novel finding.Adrenocortical carcinoma (ACC), a rare and aggressive neoplasia, presents poor prognosis when metastatic at diagnosis and limited therapies are available. Specific and sensitive markers for early diagnosis and a monitoring system of therapy and tumor evolution are urgently needed. The liquid biopsy represents a source of tumor material within a minimally invasive blood draw that allows the recovery of circulating tumor cells (CTCs). CTCs have been recently shown to be detectable in ACC. In the present paper, we evaluated the prognostic value of CTCs obtained by size-filtration in a small pilot cohort of 19 ACC patients. We found CTCs in 68% of pre-surgery and in 38% of post-surgery blood samples. In addition, CTC clusters (CTMs) and cancer associated macrophages (CAMLs) were detectable in some ACC patients. The median number of CTCs significantly decreased after the mass removal. Finally, stratifying patients in high and low pre-surgery CTC number groups, assuming the 75th percentile CTC value as cut-off, CTCs significantly predicted patients’ overall survival (log rank = 0.005), also in a multivariate analysis adjusted for age and tumor stage. In conclusion, though preliminary and performed in a small cohort of patients, our study suggests that CTC number may represent a promising marker for prognosis and disease monitoring in ACC.

A microfluidic platform for cultivating ovarian cancer spheroids and testing their responses to chemotherapies

There is increasing interest in utilizing in vitro cultures as patient avatars to develop personalized treatment for cancer. Typical cultures utilize Matrigel-coated plates and media to promote the proliferation of cancer cells as spheroids or tumor explants. However, standard culture conditions operate in large volumes and require a high concentration of cancer cells to initiate this process. Other limitations include variability in the ability to successfully establish a stable line and inconsistency in the dimensions of these microcancers for in vivo drug response measurements. This paper explored the utility of microfluidics in the cultivation of cancer cell spheroids. Six patient-derived xenograft (PDX) tumors of high-grade serous ovarian cancer were used as the source material to demonstrate that viability and epithelial marker expression in the microfluidic cultures was superior to that of Matrigel or large volume 3D cultures. To further demonstrate the potential for miniaturization and multiplexing, we fabricated multichamber microfluidic devices with integrated microvalves to enable serial seeding of several chambers followed by parallel testing of several drug concentrations. These valve-enabled microfluidic devices permitted the formation of spheroids and testing of seven drug concentrations with as few as 100,000 cancer cells per device. Overall, we demonstrate the feasibility of maintaining difficul-to-culture primary cancer cells and testing drugs in a microfluidic device. This microfluidic platform may be ideal for drug testing and personalized therapy when tumor material is limited, such as following the acquisition of biopsy specimens obtained by fine-needle aspiration.

Circulating Tumour DNA as a Biomarker Source in Metastatic Prostate Cancer

Tumour molecular features are increasingly linked to treatment response and patient prognosis in advanced prostate cancer. Plasma cell-free circulating tumour DNA (ctDNA) isolated from a minimally invasive blood draw offers a convenient source of tumour material to develop clinical biomarkers. Importantly, the burden of ctDNA in the blood has strong prognostic implications at different points during the natural history of metastatic progression. In prostate cancer, the identification of somatic profiles from ctDNA requires a broad next-generation sequencing approach because of the low mutation rate and frequent structural rearrangements. Nevertheless, comparison of genomic profiles between liquid and tissue biopsies has demonstrated that ctDNA is a surrogate for tumour tissue in the metastatic setting. Our understanding of resistance to androgen receptor (AR) directed therapies has been significantly augmented by the frequent detection of AR gene amplifications, mutations, and structural rearrangements via liquid biopsy. Furthermore, early studies suggest that distinct molecular subtypes derived from ctDNA profiling can help determine the optimal therapeutic regimen for an individual patient and enable real-time monitoring for therapy response and resistance. Indeed, in clinical trials targeting the DNA damage repair pathway in prostate cancer, ctDNA-based assessment of DNA repair status is already under evaluation as a predictive biomarker. Recent advances in the study of circulating DNA fragments now make it possible to interrogate aspects of the epigenome. In this review, we describe the various applications of plasma ctDNA in metastatic prostate cancer, including its potential role as a clinically informative liquid biomarker.

Aberrations of the number of copies (CNA) in the genome of luminal B breast tumor

Aim. To describe the CNA (Copy Number Aberration) landscape of luminal B breast tumor before treatment. Materials and methods. The study included 100 patients with breast cancer (BC) of luminal B subtype for which a biopsy of the tumor material was performed prior to neoadjuvant chemotherapy (NAC). The tumor DNA was examined using a CytoScan HD Array microarray (Affymetrix, USA). The obtained microarray data were correlated with NAC efficacy. Results. The study showed that loci 1q32.1-32.3, 1q41-42.2, and 8q24.21 had the highest frequency of amplifications (in more than 65% of patients). The highest deletion frequency (in more than 60% of patients) was found in loci 16q21, 16q22.1, 16q23.1-24.1, 17p13.1, and 17p12. Trisomy was most often observed in chromosomes 7, 8, 12, and 17, and monosomy in chromosomes 3, 4, 9, 11, 18, and X-chromosomes. The CNA landscape of luminal B subtype breast tumors is different from triple-negative breast cancer. The largest difference in the frequency of amplifications between patients with an objective response to NAC and patients with no response to NAC was shown in 1q24.2-42.2 loci (46%), and the largest difference in the frequency of deletions (more than 30%) between groups was in regions 6q16. 3, 11p15.4, 11q23.1, and 16q22.2-22.3. These loci can be considered potential predictive markers. Conclusion. The research determined loci with the highest amplification and deletion frequencies for luminal B breast cancer. Potential predictive markers for the given molecular subtype were identified.

1246P Hybrid capture-based assays in primary diagnostics of NSCLC patients: Results from the NEOlung study

Routine molecular screening of non-small cell lung cancer (NSCLC) patients for actionable mutations is often challenging due to limited tumour material and assay sensitivity. NEOlung, a multi-centric exploratory study evaluated the usefulness of non-invasive liquid biopsy and FFPE based hybrid capture-based next generation sequencing (NGS) assays in the primary diagnostic setting. We evaluated 201 blood (cfDNA) samples and tissue isolated DNA from 35 FFPE samples, previously tested negative for EGFR and negative or not at all for KRAS mutations. With the two hybrid-capture-based gene panels NEOplus v1 and NEOliquid v1 in combination with a proprietary bioinformatics, we performed NGS to detect point mutations, small InDels, copy number alterations and selected gene fusions in up to 39 (NEOliquid v1) and 94 (NEOplus v1) genes respectively. Of the 236 total samples, 23 carried a rare driver event, such as ERBB2 or BRAF activating mutations or ALK- or ROS1-fusion based on pre-screening, while 213 sample (183 blood and 30 FFPE) were previously documented to be negative or untested for ALK, BRAF, EGFR, ERBB2, KRAS, MET, RET, ROS1, NTRK1. In the 213 presumably pan-negative samples, NEOliquid v1 identified driver events in ALK (1), BRAF (10), EGFR (6), RET (2), ROS1 (1), ERBB2 (4), KRAS (31), MET (1) in 56 out of the 183 blood samples. NEOplus v1 identified driver events in NTRK1 (1), ALK (1), EGFR (1), KRAS (6), MET (1), RET (1), ROS1 (1), in 12 out of the 30 FFPE samples. Of the identified mutations, non-invasive NEOliquid v1 identified 12 (6.6%) samples, while FFPE-sample based NEOplus v1 identified 5 (16.7%) samples with known drug approvals. Furthermore, the detection of actionable EGFR mutations in a pre-screened, potential EGFR-negative cohort might be explained by the lower sensitivity or lack of testing in routine assays, especially with respect to non-classical EGFR mutations such as p.I744_E746delinsMK or p.G719C, p.S768I. In conclusion, we identified an additional 6.6% of patients with druggable alterations using NEOliquid v1 and 16.5% using NEOplus v1 within a presumably negative cohort, which shows the added value of hybrid capture-based NGS assays to identify clinically targetable genomic alterations.

Primary tumor cell cultures: сurrent methods of obtaining and subcultivation

Over the past decades, transplantable cell lines have been an affordable model for studying the biology and effect of chemotherapeutic drugs on tumors. However, numerous studies have shown that these cell lines are not heterogeneous enough and cannot reflect the drug resistance of tumors that occurs in some patients. Primary cell line cultures isolated from solid tumors have become widespread in personalized cancer therapy. This review discusses the basic methods for the preparation and cultivation of primary cell lines. A brief description is given of the methods for the disaggregation of tumor material using enzymatic, chemical and mechanical dissociation. The systems of cultivation of primary cell cultures. The selection of an appropriate dissociation method and cultivation is important to preserve the benefits of primary culture in preclinical studies.

High-resolution analysis of Merkel Cell Polyomavirus in Merkel Cell Carcinoma reveals distinct integration patterns and suggests NHEJ and MMBIR as underlying mechanisms.

Merkel Cell Polyomavirus (MCPyV) is the etiological agent of the majority of Merkel Cell Carcinomas (MCC). MCPyV positive MCCs harbor integrated, defective viral genomes that constitutively express viral oncogenes. Which molecular mechanisms promote viral integration, if distinct integration patterns exist, and if integration occurs preferentially at loci with specific chromatin states is unknown. We here combined short and long-read (nanopore) next-generation sequencing and present the first high-resolution analysis of integration site structure in MCC cell lines as well as primary tumor material. We find two main types of integration site structure: Linear patterns with chromosomal breakpoints that map closely together, and complex integration loci that exhibit local amplification of genomic sequences flanking the viral DNA. Sequence analysis suggests that linear patterns are produced during viral replication by integration of defective/linear genomes into host DNA double strand breaks via non-homologous end joining, NHEJ. In contrast, our data strongly suggest that complex integration patterns are mediated by microhomology-mediated break-induced replication, MMBIR. Furthermore, we show by ChIP-Seq and RNA-Seq analysis that MCPyV preferably integrates in open chromatin and provide evidence that viral oncogene expression is driven by the viral promoter region, rather than transcription from juxtaposed host promoters. Taken together, our data explain the characteristics of MCPyV integration and may also provide a model for integration of other oncogenic DNA viruses such as papillomaviruses.

Abstract 1678: Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma

Abstract Pancreatic cancer survival rate is poor, with a 5-year survival rate of 7% in the Republic of Ireland. Over the last 40 years, pancreatic cancer is one of the only solid tumor types to have minimal improvement in patient outcome. In Ireland, pancreatic cancer surgical resection is limited to two hospitals: Cork University Hospital and St Vincent's University Hospital (SVUH) in Dublin. In collaboration with SVUH, we have established Ireland's only pancreatic cancer patient-derived xenograft (PDX) biobank program. Tumor material from candidate patients following surgical resection was cold transferred and implanted subcutaneously into CB17/Icr-Prkdcscid mice. At time of implant and continuation of generations, snap frozen material was collected. Using miRNA and mRNA microarray technology, matched adjacent normal tissue, original tumor material and first generation (F1) PDX tumor material was interrogated. Differential expression analysis was carried out on all samples with comparisons of normal, tumor and F1 generation. Across all comparisons there were approximately 4000 genes and miRNAs found to be differential expressed. In focusing on genes that were upregulated in tumor samples compared to normal and further upregulated in the PDX F1 samples compared to the tumor samples, we identified 88 genes of interest. Biological processes such as cell division, mitotic cell cycle processes and cell cycle processes characterized a significant number of these genes. Two of the key genes of interest in this analysis were TSPAN1 and TPX2. TSPAN1 was upregulated 9.5-fold in tumor-normal comparison and upregulated a further 2.3-fold in the PDX F1 compared to the patient tumor. TPX2 was upregulated 4.4-fold in the tumor-normal comparison and a further 3.9-fold increase in the PDX tumor compared to patient tumor. TSPAN1 has previously been shown to increase the metastatic and invasive potential of pancreatic ductal adenocarcinoma cell lines. TPX2, a microtubule-associated protein, has been shown to reduce tumor growth in vivo when silenced. The pancreatic PDX biobank represents a versatile, expandable patient cohort for preclinical investigation. Analysis of gene expression profiles of normal vs tumor and tumor Vs PDX showed genes with associated tumor proliferation and aggressiveness. Citation Format: Sandra Roche, Fiona O'Neill, Niall Swan, Ninfa L. Straubinger, Neil T. Conlon, Jean Murphy, Kevin Conlon, Ray McDermott, Justine Meiller, Justin Geoghegan, Michael Moriarty, Robert M. Straubinger, Martin Clynes. Establishment and characterization by expression microarrays of a patient-derived xenograft biobank for human pancreatic adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1678.

Abstract 3191: Detection of molecular drivers in inflammatory myofibroblastic tumor: study on archival tissue from EORTC 90101 “CREATE” phase II clinical trial

Abstract Background. Inflammatory myofibroblastic tumor (IMFT) is a rare mesenchymal neoplasm, mainly driven by anaplastic lymphoma kinase (ALK) rearrangement, which is present in 50% of cases and target for ALK inhibition. For the current project we used tumor material from IMFT patients treated with the ALK/ROS1/MET inhibitor crizotinib in the frame of EORTC 90101, where IMFT patients were attributed to ALK+/- sub-cohorts based on the presence (>15% of cells) or absence (<15%) of ALK rearrangement by fluorescence in situ hybridization (FISH) and/or immunohistochemistry (IHC) [Schöffski at al. Lancet Respir Med. 2018]. The aim of the project was to evaluate the frequency of ALK rearrangement, compare different methods of ALK detection, perform a detailed characterization of ALK rearrangement partners, and to identify other potential molecular drivers with potential pharmacodynamic relevance. Material and Methods. Archival material from 24 IMFT cases, both primary or metastatic samples, was analyzed by IHC using ALK antibodies: ALK1 (DAKO) and ALK-D5F3 (Cell Signalling), and pan-NTRK (Ventana, clone EPR17341). ALK and ROS1 rearrangement were studied by FISH and fusion genes were detected using the Archer CTL Fusion Panel. Results. ALK immunopositivity by ALK1 and ALK-D5F3 was observed in 14 out of 24 cases and 11/21, respectively. ALK rearrangement by FISH was found in 13/23 samples. With Archer, fusion transcripts were identified in 13/20 specimens, all but one involving ALK with 11 different fusion partners. In one case we detected an ETV6-NTRK3 fusion; NTRK positivity was confirmed by IHC. Interestingly, the NTRK fusion case responded to crizotinib, which shows cone anti-NTRK activity [Okamura et al. JCO Precis Oncol 2019]. We did not detect ROS1 rearrangement by FISH in any sample. Two samples with ALK rearrangement by Archer were negative by FISH, with 11% and 0% of cells with ALK split signal, but both showed protein expression with both antibodies used. They responded to crizotinib with either a RECIST 1.1 complete response or stable disease, for 43 and 9 months, respectively. All but one case with ALK rearrangement by Archer were positive by ALK IHC with ALK1 antibody. The only immunonegative sample had an EML4-ALK1 fusion. Two cases were positive with ALK-D5F3 antibody but no ALK positivity was detected using ALK1, and no ALK rearrangement was detected by FISH or Archer panel, suggesting false positive results. Conclusions. ALK rearrangement is the most common driver in IMFT and the fusion can involve multiple partners. ALK1 but not the ALK-D5F3 antibody shows high ALK specificity in IMFT. The Archer CTL Fusion panel is a reliable and sensitive method for detecting fusion transcripts in IMFT, also allowing to detect alternative fusion genes, which may be responsible for the sensitivity to kinase inhibitors. Citation Format: Agnieszka Wozniak, Che-Jui Lee, Tom van Wezel, Jozef Sufliarsky, Hans Gelderblom, Jean-Yves Blay, Maria Debiec-Rychter, Raf Sciot, Judith V.M.G. Bovee, Patrick Schöffski. Detection of molecular drivers in inflammatory myofibroblastic tumor: study on archival tissue from EORTC 90101 “CREATE” phase II clinical trial [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3191.

Abstract 3453: Cancer Cell Line Factory: A systematic approach to create next-generation cancer model at scale

Abstract Precision cancer medicine is based on the ability to predict the dependencies of a given tumor from its molecular makeup. Despite successes in multiple common cancers, such prediction remains challenging for the majority of rare and understudied tumors given the absence of laboratory model systems in which to discover and/or validate therapeutic hypotheses. Here, we describe our efforts to address this challenge systematically with the ultimate goal of making it possible to learn how to predict ex vivo growth requirements for cancer samples based on technical, clinical and genomic properties of the starting tumor material. Over the last 5 years, we have processed nearly 2,000 tumor biospecimens and created over 375 genomically-confirmed patient-derived cell lines, organoids and neurosphere cultures, with >10% of these representing rare cancers. To make this possible, we have implemented three key workflows including (1) direct-to-patient sample sourcing, (2) a tissue cryopreservation and genomic credentialing system to ensure quality prior to model creation, and (3) a systematic empirical approach to screening rich medias and variations on organoid technologies ex vivo (HYBRID). We have begun performing genome-wide CRISPR viability screens in these cultures as part of our larger activities to generate a systematic laboratory-based functional map of cancer dependencies (a ‘Cancer Dependency Map'). The novel organoid, spheroid and cell line models created as part of this effort are being made publically available to the scientific community. Looking ahead, as the barriers to culturing rare tumors are overcome, we expect that preclinical functional genomics data will be useful for difficult-to-treat tumors without existing molecularly guided standard-of-care regimens. Citation Format: Yuen-Yi Tseng, Mushriq AI-Jazrawe, Rebecca Deasy, Paula Keskula, Grace Johnson, Andrew Hong, Priya Chatterji, Francisca Vasquez, Adam Bass, Barbara Van Hare, David Sandak, Keith Ligon, Jesse Boehm. Cancer Cell Line Factory: A systematic approach to create next-generation cancer model at scale [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3453.

Abstract 3919: Liquid biopsy derived organoids as a potential platform for personalized cancer therapy in metastatic prostate cancer

Abstract Introduction Circulating tumor cells (CTCs) can serve as a source of metastatic tumor material, however their low numbers often limit downstream applications. Diagnostic leukapheresis (DLA) has been shown to substantially increase CTC yield. In this study we isolated CTCs from metastatic prostate cancer (mPCa) patients by DLA to propagate them in vitro as organoid cultures. Furthermore, tumor-derived organoids were used as a model for drug discovery and sensitivity-screening, thereby exploring potential treatment selection. Methods We included 44 mPCa patients into the study and 18 were selected for DLA, based on the presence of ≥5 CTCs/ 7.5 mL blood. We optimized the DLA procedure by comparing low versus high density settings and their impact on CTC isolation efficacy. As the DLA product contains a median of 8.6*10^9 white blood cells (WBC), stringent enrichment methods are needed. CTC enrichment from DLA product was performed by antibody-based WBC depletion alone, or combined with subsequent EpCAM based enrichment. Enriched CTC fractions were cultured in vitro under optimized conditions, to initiate organoid expansion. Results We show that DLA is a safe and efficient method to collect large amounts of CTCs from mPCa patients. With optimized DLA settings we were able to improve CTC enrichment and observed a non-significant increase in CTC yield from DLA (median CTC recovery 15339 vs 5796, P=0.125). WBC depletion alone was found to reduce WBCs by ~2000-fold while retaining >50% of the CTCs, resulting in a WBC to CTC ratio of 545:1. We were able to culture and confirm CTC-derived organoids in 9/18 samples, including one organoid cell line, EMC-PCa-41. Whole Genome Sequencing (WGS) of EMC-PCa-41 revealed a triploid genome characterized by focal amplification of AR, a TMPRSS2-ERG fusion, a PTEN deletion and multiple inter-chromosomal rearrangements. Next we determined copy number profiles in single CTCs and matched organoids from two patients using shallow WGS. These data confirm prior data that CTCs represent the inherent intra-patient heterogeneity and organoids resemble CTCs from the original DLA product. Moreover, we performed an in vitro drug screen with the organoid cell line EMC-PCa-41, and found that it has a limited response to Enzalutamide, which correlated with the relatively short response to Enzalutamide that was observed in the patient. Conclusion Overall our study demonstrates that DLA provides a high CTC yield which enables short-term organoid cultures that preserve the genomic hallmarks of prostate cancer. Viable CTCs obtained by DLA may serve as a (personalized) drug screening system in metastatic prostate cancer. Citation Format: Lisanne Mout, Lisanne F. van Dessel, Jaco Kraan, Anouk C. de Jong, Rui P. Neves, Sigrun Erkens-Schulze, Anieta M. Siewerts, Job van Riet, Ronald de Wit, Stefan Sleijfer, Paul Hamberg, Yorick Sandberg, Peter A. te Boekhorst, Harmen J. van de Werken, John W. Martens, Nikolas H. Stoecklein, Wytske M. van Weerden, Martijn P. Lolkema. Liquid biopsy derived organoids as a potential platform for personalized cancer therapy in metastatic prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3919.

Abstract 4077: Quantitative proteomics reveals novel immunomodulatory pathways of resistance to PARP therapy

Abstract Background Pharmacological inhibition of PARP results in the specific killing of BRCA1/2 deficient tumor cells due to a synthetic lethal interaction between the concomitant impairment in homologous recombination and the DNA damage response. Despite the success of this approach, resistance to PARP inhibition has been observed in majority of patients with advanced cancer. Novel ways of interrogating PARP resistance are necessary to further elucidate the mechanisms of drug resistance and help identify ways to overcome it. To probe potential mechanisms of resistance we applied data-independent acquisition (DIA) mass spectrometry for unbiased global protein quantification in patient derived xenografts with demonstrated resistance to PARP inhibitors. Methods Patient-derived tumor xenografts (PDTXs) were generated from breast cancer patient tumor material implanted in severely immuno-compromised NOD-scid IL2rgnull (NSG) mice. PDTXs, developed as part of the CRUK Cambridge Institute biobank of PDTXs, have previously undergone extensive molecular profiling. PDTXs and short-term cultured PDTX cells (or PDTCs) capture most of originating patient's sample features, including heterogeneity, and consequently, the PDTX/PDTC platform is a robust intermediate in oncogenic drug development. Resistance to the PARP inhibitors AZD-2281 (olaparib) and BMN-673 (talazoparib) was tested ex vivo in PDTCs from 6 sensitive and 11 resistant PDTXs. Deep quantitative proteome profiling of PDTXs samples was conducted by applying an LC-MS/MS setup operated in DIA mode. Data was extracted using Spectronaut™ (Biognosys) with a sample specific spectral library. Pathway analysis was conducted to highlight dysregulated biological functions and pathways and the proteomics data was correlated with transcriptomics readouts. Results LC-MS/MS profiling allowed the identification of more than 11'000 proteins with more than 8'700 proteins quantified across the samples. 448 human and 430 murine proteins were significantly changed between PARP inhibitor resistant and sensitive PDTX models. Resistant models were characterized by increased expression of DNA damage response proteins including ATR and FANCD2, downregulation of TP53, TP53BP1, POLB and H2AFX, and upregulated EGFR, BRAF, ERBB2, STAT3, MLLT4 and CDKN2A. Most interestingly, we observed upregulation of human CD47/SIRPa immunomodulatory signals and upregulation of mouse Ly6G, CSF1R and SHP-1 suggesting the infiltration of immunosuppressive neutrophils and monocytes in the tumor microenvironment in the models resistant to PARP inhibition. Conclusions To our knowledge, this is the first report aiming at interrogating PARP inhibitor resistance with unbiased quantitative proteomics. The proteomics data confirmed prior observations of resistance mechanisms to PARP and elucidated potential novel mechanisms involving modulation of the immune response in resistant tumors. Citation Format: Jakob Vowinckel, Yuehan Feng, Dimitra Georgopoulou, Alejandra Bruna, Tobias Treiber, Abigail Shea, Giulia Lerda, Martin O'Reilly, Kristina Beeler, Carlos Caldas. Quantitative proteomics reveals novel immunomodulatory pathways of resistance to PARP therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4077.

Implementing cell-free DNA of pancreatic cancer patient-derived organoids for personalized oncology.

One of the major challenges in using pancreatic cancer patient-derived organoids (PDOs) in precision oncology is the time from biopsy to functional characterization. This is particularly true for endoscopic ultrasound-guided fine-needle aspiration biopsies, typically resulting in specimens with limited tumor cell yield. Here, we tested conditioned media of individual PDOs for cell-free DNA to detect driver mutations already early on during the expansion process to accelerate the genetic characterization of PDOs as well as subsequent functional testing. Importantly, genetic alterations detected in the PDO supernatant, collected as early as 72 hours after biopsy, recapitulate the mutational profile of the primary tumor, indicating suitability of this approach to subject PDOs to drug testing in a reduced time frame. In addition, we demonstrated that this workflow was practicable, even in patients for whom the amount of tumor material was not sufficient for molecular characterization by established means. Together, our findings demonstrate that generating PDOs from very limited biopsy material permits molecular profiling and drug testing. With our approach, this can be achieved in a rapid and feasible fashion with broad implications in clinical practice.

Comprehensive serial biobanking in advanced NSCLC: feasibility, challenges and perspectives

BackgroundAvailability of tumor material at baseline and disease progression is increasingly important for patient management in non-small-cell lung cancer (NSCLC), especially for the application of targeted therapies like tyrosine kinase inhibitors and for immune checkpoint inhibitor treatment. Here we report the experience of prospective biomaterial acquisition in advanced NSCLC from a pilot project.MethodsMain objective was the longitudinal collection of high-quality, cryoconserved biopsies in addition to formalin-fixed paraffin-embedded (FFPE) biopsies required for routine diagnostics, along with blood samples and detailed clinical annotation using standardized questionnaires.ResultsOver five years, 205 patients were enrolled for the project, yielding 387 cryoconserved biopsies and 1,098 serum, plasma and buffy-coat samples. The feasibility of obtaining the cryoconserved biopsies in addition to the FFPE biopsies was 89% for newly diagnosed cases, but dropped down to 56% and 47% at first and second disease progression, respectively. While forceps biopsy was the preferred procedure for tissue acquisition, the highest tissue amounts were received using the cryobiopsy method. Biopsies had a median tumor cellularity of 34% and yielded in median 13.6 µg DNA and 12 µg RNA (median RIN =8). During the five-year project, a maximum of 38 follow-up blood samples per patient were assembled in up to four therapy lines.ConclusionsDespite the poor condition and limited prognosis of most NSCLC patients, this serial biomaterial acquisition including routine collection of cryoconserved biopsies is feasible to support individualized management. The standardized collection of high-quality material has enabled and enriched several translational research studies that can advance therapeutic options.

Targeted RNAseq of Formalin-Fixed Paraffin-Embedded Tissue to Differentiate Among Benign and Malignant Adrenal Cortical Tumors.

Lack of routine fresh or frozen tissue is a barrier to widespread transcriptomic analysis of adrenal cortical tumors and an impediment to translational research in endocrinology and endocrine oncology. Our group has previously pioneered the use of targeted amplicon-based next-generation sequencing for archival formalin-fixed paraffin-embedded (FFPE) adrenal tissue specimens to characterize the spectrum of somatic mutations in various forms of primary aldosteronism. Herein, we developed and validated a novel 194-amplicon targeted next-generation RNA sequencing (RNAseq) assay for transcriptomic analysis of adrenal tumors using clinical-grade FFPE specimens. Targeted RNAseq-derived expression values for 27 adrenal cortical tumors, including aldosterone-producing adenomas (APA; n=8), cortisol-producing adenomas (CPA; n=11), and adrenal cortical carcinomas (ACC; n=8), highlighted known differentially-expressed genes (DEGs; i. e., CYP11B2, IGF2, etc.) and tumor type-specific transcriptional modules (i. e., high cell cycle/proliferation transcript expression in ACC, etc.), and a subset of DEGs was validated orthogonally using quantitative reverse transcription PCR (qRT-PCR). Finally, unsupervised hierarchical clustering using a subset of high-confidence DEGs revealed three discrete clusters representing APA, CPA, and ACC tumors with corresponding unique gene expression signatures, suggesting potential clinical utility for a transcriptomic-based approach to tumor classification. Overall, these data support the use of targeted amplicon-based RNAseq for comprehensive transcriptomic profiling of archival FFPE adrenal tumor material and indicate that this approach may facilitate important translational research opportunities for the study of these tumors.

Label-free quantitative mass spectrometry from formalin-fixed paraffin-embedded samples of nasopharyngeal carcinoma: Preliminary results from a non-endemic European cohort of patients.

Report our results of biomarker discovery in formalin-fixed paraffin-embedded (FFPE) nasopharyngeal carcinoma (NPC) via proteomic analysis. Nasopharyngeal carcinoma (NPC) is a rare cancer in Western countries. Proteomic analysis have already been reported as a useful tool to provide biomarkers. Formalin-fixed paraffin-embedded (FFPE) samples, despite largely underused, can provide invaluable information for biomarker research via proteomic analysis. FFPE samples of NPC were submitted to protein extraction followed by FASP-digestion and label-free quantitative mass spectrometry (MS). Patients' received concurrent chemoradiation with or without adjuvant chemotherapy as per Intergroup 0099 trial. IMRT was delivered following the RTOG0615 specifications. Toxicity was scored using the CTCAE 4.03 tables. Survival was estimated using Kaplan-Meier curves. Log-rank was used to detect differences. KEGG ontology graphics were generated. 28 FFPE samples from NPC patients were used. Patients were: 79% male, 97% Caucasians, 86% WHO type 3, 40% T1, 10% T2, 25% T3, and 25% T4. With a median follow up of 37 months, local control was 83 (T1, 100% T2, T3 and T4), overall survival was 84%, and six patients developed distant metastases. All five patients that died were due to metastatic disease. Tumor samples contained a median of 75% of tumor material. We found Epstein-Barr (EBV) and Herpes simplex (HSV) viruses' related proteins significantly present in early-stage primary NPC (T1 and T2, p<0.01). A pool of 10 proteins was statistically up-regulated in the metastatic group of patients (p<0.01). Median survival from this M1 group was <1 year (p<0.001). FFPE samples yielded adequate material for MS analysis. We found EBV and HSV related proteins on early-stage NPC, and proteomic profiling associated with distant metastases, potential candidates of disease biomarkers. Validation is needed.

Abstract IA12: The Ovarian Tumour Tissue Analysis Consortium: Stratified Prognosis of Ovarian Tumors (OTTA-SPOT) signature for high-grade serous ovarian cancer

Abstract Background: High-grade serous ovarian cancer (HGSOC) is the most common and aggressive epithelial ovarian cancer. HGSOC has poor survival, with five-year survival of less than 40%, as it is often diagnosed at a late stage. The median overall survival (OS) is approximately four years. Prognostic gene expression signatures for HGSOC have been inconsistent and have not been translated into clinical practice. The aim of this study was to develop a robust prognostic signature for HGSOC, in order to identify high-risk patients requiring alternative treatments. Methods: A meta-analysis of 1,455 tumors was performed and 200 prognostic genes were selected for expression profiling. An additional 315 candidate genes were selected from the literature, drug-targetable pathways, and other hypotheses. NanoString expression analysis of the 513 genes was performed on formalin-fixed, paraffin-embedded (FFPE) tumor tissue from 3,769 women with HGSOC from the Ovarian Tumor Tissue Analysis (OTTA) Consortium. A prognostic model for 5-year survival was developed using regression-based and machine learning methods. The model was trained on 2,702 tumors and evaluated on an independent set of 1,067 tumors. A NanoString expression analysis was performed on 2,692 additional tumors, for a subset of 218 of the genes, including the prognostic signature. Results: Expression of 276 genes was associated with OS (false discovery rate (FDR) &amp;lt; 0.05) in single-gene analyses adjusted for age, stage, and race. The top five genes were TAP1, ZFHX4, CXCL9, FBN1, and PTGER3 (p &amp;lt;&amp;lt; 0.001). A 101-gene prognostic signature was established, where a gain of one standard deviation in the gene expression score conferred a greater than two-fold increase in risk of death (HR (hazard ratio) = 2.35 [2.02, 2.71]; p &amp;lt;&amp;lt; 0.001). Median survival by quintile group was 9.5, 5.4, 3.8, 3.2, and 2.3 years. Sensitivity analyses, applying the signature to specific patient groups, showed that the prognostic power of the signature is not explained by residual disease, treatment, BRCA status, or CD8 score. The prognostic signature was enriched in pathways with treatment implications, such as PI3K, GPCR, and immune. This signature is suitable for use in FFPE tumor material and future cases can be assigned an HR from the gene expression score. The signature was developed in cases that did not receive neoadjuvant treatment (NACT); however, application to NACT cases was assessed in the second NanoString expression analysis. Conclusion: The OTTA-SPOT (Ovarian Tumor Tissue Analysis consortium – Stratified Prognosis of Ovarian Tumors) gene expression signature may improve risk stratification in clinical trials by identifying patients who are least likely to achieve 5-year survival. Citation Format: Joshua Millstein, Timothy Budden, Ellen L. Goode, Michael S. Anglesio, Aline Talhouk, OTTA consortium, David G. Huntsman, David D. Bowtell, James D. Brenton, Jennifer A. Doherty, Paul P.D. Pharoah, Susan J. Ramus. The Ovarian Tumour Tissue Analysis Consortium: Stratified Prognosis of Ovarian Tumors (OTTA-SPOT) signature for high-grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr IA12.