Tumor Material Research Articles

Can evaluation of mismatch repair defect and TILs increase the number of triple-negative breast cancer patients eligible for immunotherapy?

BackgroundProgrammed-cell-death-ligand 1 (PD-L1) inhibitor treatment is approved for metastatic/recurrent, PD-L1 positive, triple-negative breast cancer (TNBC) and solid tumors with mismatch repair (MMR) defect regardless of PD-L1 status. The analytical validity of PD-L1 has been questioned and adding evaluation of tumor-infiltrating lymphocytes (TILs) may identify patients likely to respond to immunotherapy. We investigated the association between MMR-deficiency and PD-L1 in TNBC; aiming to identify PD-L1 negative, TNBC patients that may be candidates for anti-PD-L1 immunotherapy. MethodologyParaffin-embedded tumor material from 44 TNBC patients was included. In 38 cases, immunohistochemical-staining´s on whole-slide sections were successful for all four MMR proteins (MSH2, MSH6, MLH1 and PMS2) and PD-L1 in 36 cases. MMR-status was categorized as positive (pMMR), heterogeneous (hMMR) or deficient (dMMR). Tumor-infiltrating lymphocytes (TILs) were evaluated on H&E sections. ResultsMMR stainings showed substantial intratumor heterogeneity. Four of 38 cases (11%) were recorded as dMMR with loss of ≥ 1 MMR-protein and 19 cases (50%) showed heterogeneous expression or partial loss (hMMR) of ≥ 1 MMR-protein. Three of 22 PD-L1 negative cases were dMMR (14%) and ten cases hMMR (45%). 16 of 22 PD-L1 negative cases (73%) showed high TILs. ConclusionsA substantial proportion of PD-L1 negative, TNBC patients showed complete/partial loss of MMR and/or high TILs indicating that supplementing PD-L1 examination with these biomarkers may identify TNBC-patients that may be selected for immunotherapy.

Percutaneous Core Needle Biopsy Can Efficiently and Safely Diagnose Most Primary Bone Tumors.

A biopsy is a prerequisite for the diagnosis and evaluation of musculoskeletal tumors. It is considered that surgical biopsy provides a more reliable diagnosis because it can obtain more tumor material for pathological analysis. However, it is often associated with a significant complication rate. Imaging-guided percutaneous core needle biopsy (PCNB) is now widely used as an alternative to surgical biopsy; it appears to be minimally invasive, possibly with lower complication rates. This study evaluates the diagnostic yield of the preferred use of PCNB in a referral center, its accuracy, and its complication rate. The data relating to the biopsy and the histological analysis were extracted from the database of a bone tumor reference center where PCNB of bone tumors was discussed as a first-line option. 196 bone tumors were biopsied percutaneously between 2016 and 2020. They were located in the axial skeleton in 21.4% (42) of cases, in the lower limb in 58.7% (115), and in the upper limb in 19.9% (39) cases. We obtained a diagnosis yield of 84.7% and a diagnosis accuracy of 91.7%. The overall complication rate of the percutaneous biopsies observed was 1.0% (n = 2), consisting of two hematomas. PCNB performed in a referral center is a safe, precise procedure, with a very low complication rate, and which avoids the need for first-line open surgical biopsy. The consultation between pathologist, radiologist, and clinician in an expert reference center makes this technique an effective choice as a first-line diagnosis tool.

The identification of circulating tumour DNA using MassARRAY technology in non-small-cell lung cancer (NSCLC)

ObjectivesAttaining tumour material from lung cancer patients can be challenging with limited sample availability. Therefore, non-invasive means of assessing tumour material is becoming increasingly more important. Circulating tumour DNA (ctDNA), extracted from a blood sample is appealing for the patient, and can be performed serially over the course of treatment. Materials and MethodsHere, we describe an approach for profiling the blood samples of 103 NSCLC patients for 73 variants in ctDNA across a panel of actionable lung cancer mutations using the UltraSEEK lung Panel (Agena Biosciences). ResultsOur cross-sectional study showed tumour and blood concordance in the detection of KRAS mutations (G12C, G12D, G12A/V, G12R, G12RC, Q61H) in 17/27 (63%), EGFR mutations (e746_a750del, e747_A750, T790M, L861Q) in 16/20 (80%) with additional PIK3CA_p545K mutations across both cohorts. In patients without reported tumour mutations, 11/56 (19.6%) presented with plasma mutations across EGFR, KRAS and PIK3CA. Where ctDNA mutations were measured longitudinally (n = 4 patients), the individual mutations mirrored the response to therapy/progression of disease. ConclusionWhilst preliminary, this study demonstrates the utility of detecting clinically actionable mutations in the blood samples of NSCLC patients at the time of presentation, and over the course of therapy.

Integrated Analysis Of Immunotherapy Treated Clear Cell Renal Cell Carcinomas: An Exploratory Study.

Molecular or immunological differences between responders and nonresponders to immune checkpoint inhibitors (ICIs) of clear cell renal cell carcinomas (ccRCCs) remain incompletely understood. To address this question, we performed next-generation sequencing, methylation analysis, genome wide copy number analysis, targeted RNA sequencing and T-cell receptor sequencing, and we studied frequencies of tumor-infiltrating CD8+ T cells, presence of tertiary lymphoid structures (TLS) and PD-L1 expression in 8 treatment-naive ccRCC patients subsequently treated with ICI (3 responders, 5 nonresponders). Unexpectedly, we identified decreased frequencies of CD8+ tumor-infiltrating T cells and TLS, and a decreased expression of PD-L1 in ICI responders when compared with nonresponders. However, neither tumor-specific genetic alterations nor gene expression profiles correlated with response to ICI or the observed immune features. Our results underline the challenge to stratify ccRCC patients for immunotherapy based on routinely available pathologic primary tumor material, even with advanced technologies. Our findings emphasize the analysis of pretreated metastatic tissue in line with recent observations describing treatment effects on the tumor microenvironment. In addition, our data call for further investigation of additional parameters in a larger ccRCC cohort to understand the mechanistic implications of the observed differences in tumor-infiltrating CD8+ T cells, TLS, and PD-L1 expression.

Significant difference in response of malignant tumor cells of individual patients to photodynamic treatment as revealed by digital holographic microscopy.

The investigation of in-vitro response of cell cultures derived from tumor material of individual patients with similar tumor localizations to photodynamic treatment is presented. Tumor types included in the research were renal cell carcinoma, melanoma and alveolar, synovial, lypo- and osteo- sarcomas. Long-term observations of treatment-induced morphological changes in cells were performed by means of digital holographic microscopy. A substantial variance in response of cells of individual patients with similar tumor types and localizations to photodynamic treatment with the same dose has been observed. These peculiarities are indicative of the demand to personalized protocols of photodynamic treatment. The elevated resistance of cells of some patients to treatment at high doses highlights potential limitations of photodynamic therapy for some patients. Digital holographic microscopy is shown to be an informative label-free noninvasive tool allowing for long-term monitoring of cell samples in vitro and providing quantitative information on necrosis rate and loss of cellular dry mass. The developed methodology can be generalized for analysis of cellular response to various therapies.

Impact of a Molecular Sequencing Systematic at Diagnosis in Digestive Oncology: Experience of a French Center

Introduction: Tumor-based molecular profiling has increased in the area of precision medicine. Their routine use is still limited by accessibility, cost and availability of tumor material. Materials and Methods: We retrospectively analysed the treatment received and the survival data of patients with digestive cancer who received molecular high-throughput sequencing (NGS) analyses at diagnosis. The primary objective of this single-center study was to compare the overall survival of patients who were treated with molecularly matched therapy with patients who received standard therapy. Median overall survival was calculated from initial disease diagnosis to death. Results: 528 patients were referred to the Digestive Oncology Department of the Timone Hospital in Marseille between January 2018, and November 2020 for management of digestive cancer and received high-throughput molecular sequencing. Among them, 461 patients had a digestive carcinoma (75 of them were excluded because of the presence of a GIST or a neuroendocrine tumor, a digestive localization of extra digestive cancer or the absence of follow-up in our center) and 275 had metastatic disease (synchronous or metachronous). For metastatic patients, actionable molecular alterations were identified in95 patients (43.5%) and for 13 patients (4.7%) a molecularly matched therapy was administered. There was no significant difference in median overall survival between patients who received matched therapy than patients who did not receive molecularly matched therapy (2.89 [95%CI 1.84 - 3.93] vs. 2.86 [95%CI 1.52 - 4.19], p=0.671). Conclusion: This study suggests that high-throughput genomics can improve management of patients. Although these results did not show a benefit in overall survival for tumors who harboured such actionable molecular alterations and who received molecularly matched therapy, than patients who did not receive molecularly matched therapy, they are promising. Randomized trials are needed to confirm that there is a benefit to treating patients with matched therapy based on NGS.

Prognostic value of proliferation, PD-L1 and nuclear size in patients with superior sulcus tumours treated with chemoradiotherapy and surgery

AimsThe aim of this study was to determine the relationship between proliferative activity, PD-L1 status and nuclear size changes after preoperative chemoradiotherapy (CRT) and the clinical outcome in patients with...

Presence of Urinary Exosomes for Liquid Biopsy of Clear Cell Renal Cell Carcinoma: Protocol for a Pilot Feasibility Study.

BackgroundApproximately 70%-80% of kidney cancers are clear cell renal cell carcinomas (CCRCCs). Patient management is based on imaging (abdominal ultrasound and computerized tomography), surgical excision of the tumor, and pathological analysis. A tissue biopsy is therefore necessary to confirm the diagnosis and avoid unnecessary nephrectomy. For metastatic cancers, a tissue biopsy is essential for establishing the targeted therapy. This biopsy of tumor material is invasive and painful. Other techniques such as liquid biopsy would help reduce the need for tissue biopsy. The development of a simple biological test for diagnosis is essential. CA9 is a powerful marker for the diagnosis of CCRCC. Exosomes have become a major source of liquid biopsy because they carry tumor proteins, RNA, and lipids. Urine is the most convenient biological liquid for exosome sampling.ObjectiveThe aim of this study (PEP-C study) is mainly to determine whether it is possible to detect urinary exosomal CA9 for the molecular diagnosis of CCRCC.MethodsThis study will include 60 patients with CCRCC and 40 noncancer patients. Exosomes will be isolated from urine samples and exosomal CA9 will be detected by transmission electron microscopy, flow cytometry, and reverse transcription-quantitative polymerase chain reaction.ResultsThis study is currently underway with funding support from the CHU Saint-Etienne of France.ConclusionsWe expect to demonstrate that urinary tumor exosomes could be a novel liquid biopsy to diagnose CCRCC and to guide clinicians in treatment decision-making.Trial RegistrationClinicalTrials.gov NCT04053855; https://clinicaltrials.gov/ct2/show/NCT04053855International Registered Report Identifier (IRRID)DERR1-10.2196/24423

Histopathology of Parotid Pleomorphic Adenomas: A “Pleomorphic Approach” to a Demanding Lesion

The aim of this study was to identify potential associations between epidemiologic, morphologic, and histopathologic features in pleomorphic adenomas (PAs) of the parotid gland in order to extract information about the natural course and biologic behavior of these lesions on the basis of a single-center series of 845 cases within a period of 15 years. Retrospective study in a tertiary academic center. For this study, an experienced head and neck pathologist critically re-evaluated the histological slides of the pathological specimens of all patients who underwent a parotidectomy for PA of the parotid gland between 2006 and 2020. A total of 845 cases made up our study sample. Our analysis showed a statistically significant association of the histologic subtype with younger age (P= .001) and maximal diameter (P= .044), with the hypocellular type being encountered more often in younger patients and in smaller lesions. The same subtype was significantly associated with an incomplete capsule (P= .001), pseudopodia (P= .006), and satellite nodules (P= .001). An incomplete capsule was associated with the presence of pseudopodia (P= .001) and satellite nodules (P= .001). It seems that various histologic subtypes have different capsule-producing properties. Apparently, over the course of time, tumor material builds a finger-like projection still inside the capsule, separates itself from the parenchyma with fibrous tissue still remaining enclosed within the capsule (pseudopodium), slowly penetrates the capsule (incomplete capsule), and leaves the main lesion taking a part of the capsule with it (satellite nodules). Laryngoscope, 132:73-77, 2022.

Abstract 3040: Inhibition of Exportin-1 as part of combinatorial treatment for patients with high-risk neuroblastoma

Abstract Background: In many adult cancers, upregulation of the nuclear-to-cytoplasmic transport protein Exportin-1 (XPO1) correlates with poor outcome and responsiveness to selinexor, an FDA-approved XPO1 inhibitor. Similar data are emerging in childhood cancers, for which selinexor is being evaluated in early phase clinical studies. Our aims are to identify patients most likely to benefit from selinexor combination therapy and define the cellular mechanism responsible this effect. We hypothesize that selinexor and the proteasome inhibitor, bortezomib, act synergistically to decrease NF-kB-mediated proliferation by halting excessive exportation and proteasome degradation of IkB, an XPO1 cargo protein. Methods: We performed ion intensity-based label-free semiquantitative proteomic profiling on primary tumor material from fifty patients with uniformly treated high-risk NB, half of whom were long term survivors and half of whom died <18 months from diagnosis from disease progression. We cross-referenced this dataset with gene expression profiling data available through the R2 database. A panel of neuroblastoma cell lines was screened for XPO1 expression using Western blotting, sensitivity to selinexor and bortezomib as single agents, and in combination using cellular viability assays. Localization and quantification of IkB after vehicle or selinexor treatment was done by confocal imaging, using immunofluorescent labeling and Volocity software. Flow cytometry was used to define treatment effect on cell cycle arrest and apoptosis using BrdU and Annexin-V labeling, respectively. siRNA-mediated knockdown of IkB was used to investigate the relationship between presence of IkB and drug effectiveness. NF-kB activity was measured with a luciferase assay. Results: High tumor protein and gene expression of XPO1 correlates with poor outcome. Neuroblastoma cell lines demonstrate variably high XPO1 expression compared to normal tissue, as well as sensitivity to selinexor (IC50 range 4-300nM). IkB is retained in the nuclear compartment after treatment with selinexor. When selinexor is used in combination with bortezomib the effect on cell proliferation is synergistic. Flow cytometry demonstrates that selinexor alone contributes to G1-0 arrest while combination treatment results in significantly enhanced apoptosis. Measurement of NF-kB transcriptional activity shows decrease in activity with single agents and the least amount of activity in combination and siRNA against IkB diminishes the effect of single and combination treatment. Conclusions: This work demonstrates that XPO1 expression is a biomarker of highly aggressive neuroblastoma and may define patients most likely to be responsive to treatment with selinexor-based combinatorial therapies. Synergistic treatment effect with selinexor and bortezomib is mediated, in part, through the presence of IkB to regulate NF-kB signaling. Citation Format: Basia Galinski, Yossef Landesman, Daniel Weiser. Inhibition of Exportin-1 as part of combinatorial treatment for patients with high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3040.

Abstract 1788: Increasing the therapeutic index of IL12 by engineering for tumor specific protease activation

Abstract IL-12 is a cytokine produced by antigen-presenting cells that increases T cell proliferation, IFN gamma mediated Th1 effector functions and T and NK cell cytotoxicity. While these effects generate potent anti-tumor immunity in mouse models, the high toxicity of IL-12 in cancer patients has limited its clinical utility. Potency attenuation and intratumoral cytokine localization may improve IL-12 tolerability, but these approaches can reduce efficacy or be limited by intratumoral delivery or tumor antigen expression. To improve both tolerability and efficacy of IL-12, we engineered IL-12Fc fusions with anti-IL-12 antibodies to block IL-12 potency. Using linkers designed to be cleaved by highly active intratumoral proteases, blocking antibodies are released specifically in the tumor microenvironment, thereby increasing intratumoral IL-12 activity. Single chain IL-12 was fused to one C-termini of an Azymetric™ Fc heterodimer. To the other Fc C-termini, an anti-IL-12 scFv was fused via a protease-cleavable linker in order to block IL-12 activity. In addition to antibody blockade, modifications of IL-12Fc fusions were used to further limit IL-12Fc activity. In vitro potency was determined by CD8T cell IFN gamma release. Anti-IL-12 scFv cleavage in the presence of recombinant enzyme or human tumor material was assessed by reducing CE-SDS and LC/MS, respectively. All IL-12Fc fusions were produced with favorable biophysical characteristics. Modified IL-12Fc molecules had up to 500x reduced potency, while antibody blocked IL-12Fc molecules had up to 100,000x reduced potency compared to IL-12Fc control. In vitro cleavage of the anti-IL-12 scFv from IL-12Fc recovered potency to that of the corresponding non-masked IL-12Fc molecules. Reducing CE-SDS confirmed that anti-IL-12 scFvs were cleaved from IL-12Fc in the presence of recombinant enzyme. Cleavage of anti-IL-12 scFvs also occurred when variants were incubated in pancreatic tumor cell supernatant or human tumor tissue lysate. These results indicate that antibody blockade and re-activation by protease cleavage is a promising strategy to localize the activity of IL-12 to the tumor microenvironment while potentially limiting off-tumor toxicities. Further modifying antibody blocked IL-12 has the potential to better fine tune therapeutic index. We are pursuing tumor-specific IL-12 fusions for clinical application in tumors with high intratumoral protease activity. Citation Format: Jennifer Leah Bishop, Ryan Blackler, Gesa Volkers, Maya Poffenberger, Irene Yu, Joel Smith, Akram Khodabandehloo, Sifa Arrafi, Desmond Lau, Liz Stangle, Leisa Stenberg, Patricia Zwierzchowski, Iulia Dude, David Douda, Grant Wickman, Jeff Proctor, Gerry Rowse, Laurence Madera, Genevieve Desjardins, Nicole Afacan, Stuart Barnscher, David Mills, Thomas Spreter, Surjit Dixit. Increasing the therapeutic index of IL12 by engineering for tumor specific protease activation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1788.

Abstract CT020: Long-term outcomes of patients with TRK fusion cancer treated with larotrectinib

Abstract Introduction: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are oncogenic drivers in various tumor types. Larotrectinib is a first-in-class, highly selective, central nervous system (CNS)-active TRK inhibitor approved in over 40 countries, including the US, for the treatment of adult and pediatric patients with TRK fusion cancer. Larotrectinib was approved by the FDA in 2018 based on efficacy and safety outcomes in a primary analysis cohort of 55 patients with TRK fusion cancer from 3 clinical trials (Drilon A et al. NEJM. 2018). Here, we report long-term efficacy follow-up for larotrectinib and molecular data on co-occurring mutations in this primary analysis cohort. Methods: Patients with non-primary CNS TRK fusion cancer treated with larotrectinib were identified from 3 clinical trials (NCT02122913, NCT02576431, NCT02637687). NTRK gene status was determined by local molecular testing. Adult and pediatric patients received larotrectinib 100 mg and 100 mg/m2 twice daily, respectively. The primary endpoint was investigator-assessed objective response rate (ORR) (per RECIST v1.1). Next-generation sequencing was performed on pre-treatment tumor samples from a subset of patients with evaluable tumor material (n=31) using the FoundationOne® CDx assay. The data cut-off was July 15, 2019. Results: A total of 55 patients with 17 different tumor types were included in the primary analysis cohort. Median age was 45 years (range 0.3-76 years). Patients had gene fusions involving NTRK1 (45%), NTRK2 (2%), or NTRK3 (53%). For 31 patients the detailed genomic profile, including co-occurring mutations, will be presented. Forty-four (80%) patients had received prior systemic therapy, with a median of 2 prior therapies (range 0-10). ORR with larotrectinib was 80% (95% confidence interval [CI] 67-90%); 13 (24%) patients had a complete response (CR), 31 (56%) patients had a partial response (PR), 5 (9%) patients had stable disease, and 6 (11%) patients had progressive disease. With longer follow-up, best response for 4 patients improved from PR to CR. Median duration of response and progression-free survival were 35.2 months (95% CI 19.8-not estimable [NE]) and 25.8 months (95% CI 9.9-NE), respectively. Median overall survival (OS) was not reached (95% CI 44.4-NE) over a median follow-up of 32.5 months. The 36-month OS rate was 76% (95% CI 63-89%). In an expanded safety population (n=279), larotrectinib-related adverse events were mainly Grade 1-2. Conclusions: Larotrectinib demonstrated a robust response rate with long durability and extended survival benefits in adult and pediatric patients with TRK fusion cancer. These data highlight the importance of identifying NTRK gene fusions in patients with cancer. Citation Format: Alexander Drilon, Shivaani Kummar, Catherine M. Albert, Ramamoorthy Nagasubramanian, Jaclyn F. Hechtman, John A. Reeves, Georg Beckmann, Marion Rudolph, Justyna A. Wierzbińska, Laura Dima, Nicoletta Brega, Theodore W. Laetsch, David S. Hong. Long-term outcomes of patients with TRK fusion cancer treated with larotrectinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT020.

Abstract 1303: AI driven single cell analysis of drug action in solid tumor material: An entry point to functional precision medicine

Abstract Introduction: The paradigm of precision oncology is the selection of optimal therapy for individual patients. However, disease complexity prevents most cases from having a clear correlation between genetics and response, and programs using driver mutations to stratify patients into treatment arms have shown lackluster results (Middleton et al 2020). In contrast, prior work by us and colleagues demonstrated that functional analysis of drug action on single cells in unmanipulated primary tumor tissues with automated microscopy and advanced image analysis can identify effective therapies for patients with hematological cancers. In a prospective interventional trial (EXALT1 NCT03096821 Snijder et al 2017 N=17, Staber et al 2020 ASH N=56) patients treated with drugs ranked by differential ex vivo response resulted in a 55% ORR and >1.3-fold PFS improvement compared to the prior therapy in 54%. However, the scope has been limited to hematological cancers and solid tumor ascites/effusions.Adapting analysis to tumor biopsies required major advances in wet lab and computation, including robust quantification of 3D confocal images. Here, we present first biological evidence from a newly developed pipeline for the ex vivo treatment and single cell interrogation of singular cell + microaggregate suspensions from ovarian cancer biopsies. Methods and results: Viable tissue from debulking surgery was obtained after consent and dissociated. The resulting cells and microaggregates were treated with >85 small molecules in 7 concentrations in triplicate for 72h, fixed, and stained for cancer surface markers. Cells were imaged with automated confocal microscopy at 20x across multiple 384 well plates, with z-resolution of <17 planes. Images were segmented with a modular analysis pipeline with custom neural networks in a scalable cloud environment, yielding precise characterization (e.g. viability, size, marker intensity) and localization of each cell, elucidating the complexity of biopsies. Single cell data in turn was used to determine the ability of drugs to induce targeted cytotoxicity and modify the immune system/pathways, cell morphology, and the 3D environment. Conclusions: High content single cell phenotypic analysis of solid tumors can enable the study of drug action in primary tissues. Compared to organoids where cells are outgrown, working with primary cells in short term incubation enables analysis of drug activity prior to culture adaptation, and the presence of immune cells enables the study of I/O drugs, in a close-to-patient setting. A challenge to achieve single cell resolution of complex mixtures of aggregate/single and adherent/non-adherent cells was overcome by confocal microscopy and AI driven 3D image analysis. The screening and follow-up data indicates this could support preclinical research, biomarker discovery, and precision medicine. Citation Format: Valentin Aranha, Diogo Tomaz, Irene Gutierrez Perez, Florian Rohrer, Joost Van Ham, Lukas Hefler, Laudia Hadjari, Judith Lafleur, Nikolaus Krall, Robert Sehlke, Bojan Vilagos, Gregory Ian Vladimer. AI driven single cell analysis of drug action in solid tumor material: An entry point to functional precision medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1303.

Simultaneous Ipsilateral Dual Embolization (transarterial chemoembolization with degradable starch microspheres and portal vein embolization) of the liver- “SIDE” technique for preoperative augmentation of future liver remnant (FLR) in patients with solid liver malignancies

Portal vein embolization (PVE) is gold standard strategy to increase future liver remnant (FLR). Up to 30% of patient with liver malignance still couldn't underwent surgery after PVE due to tumor progression and/or insufficient FLR regeneration during waiting period. Nine patients with colorectal liver metastases (CRLM) and small FLR, in close proximity to FLR critical structures (portal and/or hepatocaval confluence), having more than three criteria of Fong Clinical Risk Score for CRLM were approved by Ethical Committee for Simultaneous PVE and Transarterial Chemoembolization with Degradable Starch Microspheres (DSM-TACE). For those patients, standard PVE was simultaneously followed by oxaliplatin based DSM-TACE with short-term embolic material of the whole tumor bearing liver to be resected that allowed to achieve both tumor control and postembolic infarction in liver to be removed, as a trigger of increased FLR regeneration, without biliary tree damage. Results were compared with 23 patients in control group after standard PVE. Unprecedented FLR regeneration with kinetic growth rate 23.5 cc/day (range from 17.6 to 57.25 cc/day) was observed enabling extended hepatectomies within 2 weeks compared with 5 weeks waiting period in control group. In all CRLM about 60% (range from 40% to 90%) necrosis was achieved. There was no severe morbidity (including posthepatectomy liver failure) and mortality. We propose method of preoperative FLR adaptation which is not only second to none in the achieving liver regeneration rate but also is the only one that allows tumor control targeting both main reasons for patient dropout during waiting period for FLR regeneration.

Plasma Cell Disease Genotyping with the Liquid Biopsy

IntroductionEasily accessible, real-time genotyping is desirable for patients suffering from plasma cell (PC) disorders for diagnostic, prognostic and therapeutic purpose. However, PC disorders usually lack a leukemic phase, and up to now genotyping of tumor cells required purified material from bone marrow (BM) or tissue biopsies. Circulating cell-free DNA (cfDNA) might be an accessible source of tumor material in patients with PC diseases to identify cancer-gene somatic mutations. Accessing the peripheral blood (PB) has clear advantages with respect to the sampling procedure itself, and has the potential to better reflect tumor heterogeneity. Here we aimed at tracking the genetic profile of different PC dyscrasias using plasma cfDNA.MethodsTwenty-eight consecutive patients (median age= 64; male:female ratio=15:13) with PC disorders [two with monoclonal gammopathy of undetermined significance (MGUS), five with smoldering MM (SMM), and 21 with symptomatic MM] were included between September 2016 and May 2017. The following material was collected: (1) cfDNA isolated from plasma, (2) tumor genomic DNA (gDNA) from CD138+ purified BM PCs for comparative purposes, and (3) normal germ line gDNA extracted from PB granulocytes after Ficoll separation, to filter out polymorphisms. The sampling was done at diagnosis in 25 patients, and during the course of the disease in three MM cases. Median BM PC infiltration was 40% (range: 7-90%). A targeted resequencing gene panel, including coding exons and splice sites of 14 genes (target region: 31 kb) was specifically designed and optimized to allow a priori the recovery of at least one clonal mutation in 68% (95% confidence interval: 58-76) of MM patients. Ultra-deep next-generation sequencing (NGS) of the gene panel was performed on MiSeq (Illumina) using the CAPP-seq library preparation strategy (NimbleGen). The somatic function of VarScan2 was used to call non-synonymous somatic mutations, and a stringent bioinformatic pipeline was developed and applied to filter out sequencing errors (detection limit 3x10-3). The sensitivity and specificity of plasma cfDNA genotyping were calculated in comparison with tumor gDNA genotyping as the gold standard.ResultsIn this prospectively collected cohort of 28 unselected PC dyscrasia patients, circulating tumor cfDNA was detectable in plasma samples with a median of 12011.60 haploid genome-equivalents per mL. The application of our targeted ultra-deep NGS approach for plasma cfDNA genotyping resulted in ≥90% of the target region covered ˃1000X in all plasma samples, and ≥90% of the target region covered ˃2000X in 23/28. Overall, within the interrogated genes, 18/28 (64%) patients harbored somatic mutations (total number: 28; range: 1-4 mutations per patient) that were detectable in plasma cfDNA. Quite consistent with the typical spectrum of mutated genes in MM, plasma cfDNA genotyping revealed somatic variants of NRAS in 25%; KRAS in 14%; TP53, TRAF3 and FAM46C in 11%, respectively; CYLD and DIS3 in 7%, respectively; and BRAF and IRF4 in 4% of cases, respectively (Figure 1A). By comparing the genotype of circulating tumor cfDNA with that of gDNA from purified malignant BM PCs of the diagnostic biopsy (gold standard) (Figure 1B), we found that cfDNA genotyping correctly identified 72% of the mutations confirmed in the tumor biopsy (Figure 1C). Notably, the remaining mutations not discovered in cfDNA had a low representation in the purified BM PCs (median allelic abundance=2.5%; range 1.1-4.96%). ROC analysis showed that circulating tumor cfDNA genotyping had the highest sensitivity (92.9%) if mutations were represented in >5% of the alleles of the purified BM PCs (Figures 1D-E). In none of the cases, cfDNA genotyping identified additional somatic mutations not detected in the purified BM PCs.ConclusionsOverall, our results provide the proof of principle that circulating tumor cfDNA genotyping is a feasible, non-invasive real-time approach that reliably detects clonal and subclonal somatic mutations represented in at least 5% of alleles in tumor PCs. [Display omitted] DisclosuresBertoni:Acerta Pharma: Research Funding; Bayer: Research Funding; Cellestia: Research Funding; Menarini: Research Funding; Piqur: Research Funding; Immunogen: Research Funding. Zucca:Celgene: Honoraria, Research Funding; Jannsen: Consultancy, Honoraria, Other: Advisory role; Mundipharma: Research Funding; Celgene: Honoraria, Research Funding; Roche: Advisory role, Honoraria, Research Funding; Roche: Honoraria, Research Funding; Mundipharma: Research Funding; Gilead Science: Consultancy, Other: Advisory role; Sandoz: Consultancy, Other: Advisory role; Jannsen: Consultancy, Honoraria, Other: Advisory role; Gilead Science: Consultancy, Other: Advisory role; Celltrion Healthcare: Consultancy, Other: Advisory Role; Bayer: Consultancy, Other: Advisory Role; Sandoz: Consultancy, Other: Advisory role; Takeda: Consultancy, Other: Advisory role; Celltrion Healthcare: Consultancy, Other: Advisory Role; Takeda: Consultancy, Other: Advisory role; Bayer: Consultancy, Other: Advisory Role.

Cell Therapy With TILs: Training and Taming T Cells to Fight Cancer.

The rationale behind cancer immunotherapy is based on the unequivocal demonstration that the immune system plays an important role in limiting cancer initiation and progression. Adoptive cell therapy (ACT) is a form of cancer immunotherapy that utilizes a patient’s own immune cells to find and eliminate tumor cells, however, donor immune cells can also be employed in some cases. Here, we focus on T lymphocyte (T cell)-based cancer immunotherapies that have gained significant attention after initial discoveries that graft-versus-tumor responses were mediated by T cells. Accumulating knowledge of T cell development and function coupled with advancements in genetics and data science has enabled the use of a patient’s own (autologous) T cells for ACT (TIL ACTs). In TIL ACT, tumor-infiltrating lymphocytes (TILs) are collected from resected tumor material, enhanced and expanded ex-vivo, and delivered back to the patient as therapeutic agents. ACT with TILs has been shown to cause objective tumor regression in several types of cancers including melanoma, cervical squamous cell carcinoma, and cholangiocarcinoma. In this review, we provide a brief history of TIL ACT and discuss the current state of TIL ACT clinical development in solid tumors. We also discuss the niche of TIL ACT in the current cancer therapy landscape and potential strategies for patient selection.

OMIC-07. FEASIBILITY AND UTILITY OF EPIGENOMIC PROFILING FOR CHILDHOOD CNS TUMORS IN HONG KONG

Genome-wide DNA methylation profiling has emerged as an important diagnostic tool that complements histopathology for CNS tumors in children and adults. Literature describing its application in Asian countries is nonetheless limited. Herein, we report the feasibility and utility of adopting such platform for children diagnosed with CNS tumors in Hong Kong. A multi-institutional cohort (n=94, 97% of Chinese ethnicity) with CNS embryonal or high grade neuroepithelial tumors (HGNET) diagnosed in Hong Kong from 1996–2020 was assembled based on tissue availability. DNA was extracted from FFPE tumor material (median 301ng, range 13-1000ng), bisulfite converted and profiled with the Infinium Methylation EPIC BeadChip kit. Raw data were analyzed on the German Cancer Research Center MNP 2.0 classifier and through unsupervised dimensionality-reduction analysis (t-SNE) referencing a published CNS tumor reference dataset (GSE90496). The radio-histologic diagnosis included medulloblastoma (n=65), ATRT (n=9), pineal parenchymal tumors (n=7), ETMR (n=5), CNS-PNET (n=4) and other embryonal tumors/HGNETs (n=4). Methylation class could be assigned based on results from MNP 2.0 (calibrated score ≥ 0.9) in 62 patients (66%, including 2 clustering with control) and t-SNE in 22 (23%), while no-match was encountered in 10 (11%). Methylation-based analysis allowed confirmation of diagnosis and assignment of molecular subgroup in 64 patients (68%), confirmation of histologic diagnosis alone in 5 (5%) and resulted in revision/reassignment of diagnosis in 13 (14%). Among medulloblastoma samples that were assigned molecular tumor classes (n=57), 8 clustered with WNT-activated medulloblastoma, 13 with SHH-activated medulloblastoma, 10 with Group 3 medulloblastoma, 21 with Group 4 medulloblastoma, and 5 with non-medulloblastoma entities (high-grade gliomas=3, ETMR=1, ATRT=1). In conclusion, epigenomic profiling allowed refinement of disease classification for pediatric CNS tumors. Availability of such methodology in Asia sets the stage for international collaborations in molecularly-driven trials.

Liquid biopsy in extranodal NK/T-cell lymphoma: a prospective analysis of cell-free DNA genotyping and monitoring

Satisfactory tumor material is often hard to obtain for molecular analysis in extranodal natural killer (NK)/T-cell lymphoma (NKTCL) at present. However, the accuracy and utility of circulating cell-free DNA (cfDNA) genotyping have not been adequately assessed in NKTCL. We therefore performed targeted next-generation sequencing on tumor tissues and a series of longitudinal plasma samples prospectively collected from a cohort of high-risk NKTCL patients. Concordance of genotyping results of paired baseline tumor and cfDNA and the predictive value of dynamic cfDNA monitoring were evaluated. At baseline, 59 somatic variants in 31 genes were identified in tumor and/or plasma cfDNA among 19 out of 24 high-risk NKTCL patients (79.2%). Plasma cfDNA had a sensitivity of 72.4% for detection of somatic variants identified in tumor biopsies before treatment. Plasma cfDNA also allowed the identification of mutations that were undetectable in tumor biopsies. These results were also verified in a validation cohort of an additional 23 high-risk NKTCL patients. Furthermore, longitudinal analysis showed that patients with rapid clearance of NKTCL-related mutations from plasma had higher complete remission rates (80.0% vs 0%; P = .004) and more favorable survival (1-year progression-free survival [PFS] rate, 79.0% vs 20.0%; P = .002) compared with those with persisting or emerging mutations in plasma. In addition, low cfDNA concentration before treatment was associated with favorable survival outcome for patients with NKTCL (1-year PFS, 90.0% vs 36.4%; P = .012). In conclusion, cfDNA mirrors tumor biopsy for detection of genetic alterations in NKTCL and noninvasive dynamic plasma cfDNA monitoring might be a promising approach for tracking response and survival outcome for patients with NKTCL.

Refinement of an Established Procedure and Its Application for Identification of Hypoxia in Prostate Cancer Xenografts

Simple SummaryRegions of low oxygen status (hypoxia) are a characteristic feature of solid tumors. This hypoxia is a major cause of resistance to treatment, especially radiation therapy, and it can increase the likelihood of metastatic spread. Being able to accurately identify tumor hypoxia will allow us to predict a patient’s response to therapy and find alternative approaches to improve outcome. We have refined a dissection method that involves autoradiography and laser-guided microdissection of hypoxic areas in tumors. Using this approach, we were able to test the feasibility of applying a 15-gene signature that was previously developed for head and neck cancer patients to identify hypoxia in pre-clinical models of prostate cancer. Our results demonstrated the potential of this method to identify hypoxia in this tumor type and suggest its applicability for use in patients with prostate cancer.Background: This pre-clinical study was designed to refine a dissection method for validating the use of a 15-gene hypoxia classifier, which was previously established for head and neck squamous cell carcinoma (HNSCC) patients, to identify hypoxia in prostate cancer. Methods: PC3 and DU-145 adenocarcinoma cells, in vitro, were gassed with various oxygen concentrations (0–21%) for 24 h, followed by real-time PCR. Xenografts were established in vivo, and the mice were injected with the hypoxic markers [18F]-FAZA and pimonidazole. Subsequently, tumors were excised, frozen, cryo-sectioned, and analyzed using autoradiography ([18F]-FAZA) and immunohistochemistry (pimonidazole); the autoradiograms used as templates for laser capture microdissection of hypoxic and non-hypoxic areas, which were lysed, and real-time PCR was performed. Results: In vitro, all 15 genes were increasingly up-regulated as oxygen concentrations decreased. With the xenografts, all 15 genes were up-regulated in the hypoxic compared to non-hypoxic areas for both cell lines, although this effect was greater in the DU-145. Conclusions: We have developed a combined autoradiographic/laser-guided microdissection method with broad applicability. Using this approach on fresh frozen tumor material, thereby minimizing the degree of RNA degradation, we showed that the 15-gene hypoxia gene classifier developed in HNSCC may be applicable for adenocarcinomas such as prostate cancer.

Peripheral blood levels of tumor-infiltrating lymphocytes (TILs) and circulating tumor cells (CTCs) in patients with colorectal cancer.

e15510 Background: Tumor is a structure where malignant cells interact, among others, with cells of the adaptive and innate immune systems largely determining the tumor microenvironment. The role of TILs in the disease prognosis has been shown. The amount of CTCs is one of the factors that significantly affect the risk and rate of metastasis. The purpose of the study was to assess an association between TILs and CTCs in the peripheral blood of patients with various stages of colorectal cancer (CRC). Methods: The study included 299 patients (aged 42-86 years, mean age 64.2±1.7) with stage II-IV CRC T1-4N0-2M0-1. TILs were identified in tumor material after standard histological processing. Lymphocytes were counted per 100 epithelial cells in 5 fields of view at a magnification of x400; the result was expressed as a percentage ( < 5% weak, 5-30% moderate, >30% strong). The numbers of CTCs were measured in the peripheral blood using the Veridex CellSearch system (Janssen), taking into account the expression of epithelial cell adhesion markers EpCAM, cytokeratins 8,18,19 and absence of the CD45 expression. The blood sample was evaluated according to the following criteria: 0 CTCs, 1-3 CTCs, and more than 3 CTCs. Statistical analysis of results was performed in the Statistica 13.0 program (StatSoftInc., USA). Results: Weak lymphocytic infiltration was detected in 32.8%, moderate - in 48.1%, strong - in 19.1% of cases. CTCs were detected in 62.9% cases (in 188 of 299 patients). The percentages of patients with 1-3 CTCs and with >3 CTCs were equal - 50% (94 of 188). CTCs were not registered in 37.1% cases (111 of 299). The absence of CTCs was noted equally often in moderate and strong lymphocytic infiltration – 43.7% and 43.8%. The presence of tumor cells in the peripheral blood was most often detected in weak lymphocytic infiltration, being 1.4 times more frequent than in moderate and strong infiltration (76.5% vs. 56.3% and 56.2%) (p = 0.019, c2= 11.890). Conclusions: The study demonstrated a significant relationship between the level of CTCs and the intensity of lymphocytic infiltration in the tumor (p≤0.05), which can be used as a new prognostic approach.