Diagnostic Tissue Research Articles

Towards computationally efficient prediction of molecular signatures from routine histology images

Towards computationally efficient prediction of molecular signatures from routine histology images

OA16.01 Plasma NGS At Time of Diagnostic Tissue Biopsy – Impact on Time to Treatment: Results From a Pilot Prospective Study

The expansion of targeted therapies has transformed the treatment landscape of advanced NSCLC, however the majority of patients do not receive guideline-recommended tumor genotyping. Molecular profiling for actionable mutations is often initiated at the first medical oncology visit leading to significant treatment delays and potentially inappropriate treatment assignments if therapeutic decisions are made prior to genomic results. The role of plasma-based genomic profiling performed simultaneously with diagnostic tissue biopsy in suspected advanced NSCLC has largely been unexplored.

Combined tumor-associated macrophages biomarker predicting extremely poor outcome of patients with primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is an aggressive and rare malignancy with poor prognosis. However, there are no reliable prognostic biomarkers for PCNSL in clinical practice. Here, we aimed to identify a reliable prognostic biomarker for predicting the survival of PCNSL patients. In this study, multiplex immunofluorescence and digital imaging analysis were used to characterize tumor-associated macrophages (TAMs) immunophenotypes and the expression of programmed cell death ligand 1 on TAMs, with regard to prognosis from diagnostic tumor tissue samples of 59 PCNSL patients. We found that the M2-to-M1 ratio was a more reliable prognostic biomarker for PCNSL than M1-like or M2-like macrophage infiltration. In addition, the combination of programmed death-ligand 1 (PD-L1) expression on TAMs and the M2-to-M1 ratio in PCNSL demonstrated improved performance in prognostic discrimination than PD-L1-positive TAMs or M2-to-M1 ratio. To validate the prognostic significance of the combined TAMs associated biomarkers, they were integrated into the International Extranodal Lymphoma Study Group (IELSG) index and termed as IELSG-M index. Kaplan-Meier plots showed that the IELSG-M index could discriminate patients into low-, intermediate- or high-risk subgroups, better than IELSG, in terms of prognosis. The areas under the receiver operating characteristic curves of IELSG-M was 0.844 for overall survival; superior to the IELSG model (0.580). Taken together, this study's findings showed that the combination of PD-L1 on TAMs and the M2-to-M1 ratio could be strong prognostic predictive biomarkers for PCNSL and the IELSG-M index had improved prognostic significance than the IELSG index.

Accuracy and other quality indicators of solid pancreatic mass endoscopic ultrasound-guided fine needle aspiration and biopsy in two academic endoscopy centers.

Endoscopic ultrasound fine-needle aspiration/biopsy (EUS-FNA/FNB) is highly accurate, but discrepancies between cytological and surgical diagnoses are still observed. We aimed to determine its accuracy and monitor quality indicators in our facilities. We performed a retrospective review of all cases of pancreatic solid lesions evaluated by EUS-FNA/FNB, between July 2015 and June 2018, in two centers. Cytological and surgical findings were categorized into five groups: benign, malignant, suspect of malignancy, undetermined and insufficient for diagnosis. Final diagnosis was based on surgical diagnosis and, in patients who did not undergo surgery, on clinical outcome after 6 months follow-up. Altogether, 142 patients were included. FNA was the preferred tissue acquisition method (88%), with a predilection for the FNA 22G needle (57%). Cytology was insufficient for diagnosis in 2 cases, therefore a full diagnostic sample was available in 98.6% of the patients (>90%, ESGE target). Fifty-five (38.7%) patients underwent surgery. In term of cancer diagnosis, comparison with final surgical pathology (n=55) revealed 89% true positives, 5.5% true negatives, 3.6% false positives and 1.8% false negatives. When combining surgical diagnosis and clinical outcomes together, EUS-guided sampling sensitivity was 97.4% (92.5-99.5), specificity was 92.3% (74.9-99.1), positive predictive value was 98.2% (93.6- 99.5), negative predictive value was 88.9% (72.3-96.1) and accuracy was 96.4% (91.9-98.8). Post-procedural acute pancreatitis was reported in 2 patients (1.4%). These results reveal a performance for diagnostic tissue sampling well above the ESGE proposed target standard. Also, the uncommon high specificity illustrates the determining role of the pathologist's final interpretation and diagnosis.

ABCL-321: Clinicopathological Profile of Gastrointestinal Lymphoma Diagnosed Over a Period of 6-Years: A Tertiary Care Center Experience

Context GI lymphomas (GIL) comprise approximately 1%–10% of all malignancies that arise in the gastrointestinal tract (GIT). GILs show heterogeneity in terms of distribution patterns, histopathological subtypes, disease manifestations, and treatment offered. Objective To determine the clinicopathological profile of lymphomas in the GIT. Design This is a retrospective study. All GIL-related data were retrieved from a database maintained by the Department of Pathology, All India Institute of Medical Sciences, New Delhi. The cases with incomplete diagnoses were reviewed, and an appropriate immunohistochemistry (IHC) panel was performed, followed by reclassification according to the 2017 WHO classification. Setting This is a hospital-based study from a tertiary care hospital and referral center with maximal investment by the central government. The biopsy, hematology, and radiology workup were done as a part of patient management and came at a minimal cost. The costs of histopathological diagnosis and routine blood counts, X-rays, and biochemistry are free. Patients or Other Participants Demographic details of all the cases were retrieved from the database. We have selected only those cases that had adequate diagnostic tissue and had an incomplete diagnosis for review. Results A total of 391(8.21%) cases of GIL were identified out of 4,758 total cases of lymphomas diagnosed over a period of 6 years, from 2015 to 2020. Out of these 391 cases of GILs, 364 were primary GILs, and 27 cases were secondarily involved GIL. Males are predominantly affected (M:F=3:1). The mean age is 40.6 yrs, with a range from 2 to 88 yrs. In the GIT, the stomach is the most common site of involvement (50%), followed by small intestine (28%) and large intestine (21.25%). DLBCL-NOS is the most common GIL (56.25%), followed by MALToma (15.35%), Burkitt lymphoma (10.5%), high-grade B-cell lymphoma-NOS (6.14%), T-cell NHL (3.84%), and other rare lymphomas, including IPSID, mantle cell lymphomas, duodenal type follicular lymphoma, and plasmablastic lymphomas. Conclusions It will be the largest single-institution study from India regarding gastrointestinal distribution and various subtypes of GILs. The stomach is the most common site of involvement for GILs, and DLBCL-NOS is the most common subtype of lymphoma involving the GIT, which is similar to studies published in western literature. Grant acknowledgments SERB ECR/2015/452, EEQ/2016/402, AIIMS-A_653

The Dutch National TissueArchive Portal enables efficient, consistent, and transparent procurement of diagnostic tissue samples for scientific use

Biobanks play a crucial role in enabling biomedical research by facilitating scientific use of valuable human biomaterials. The PALGA foundation—a nationwide network and registry of histo- and cytopathology in the Netherlands—was established to promote the provision of data within and between pathology departments, and to make the resulting knowledge available for healthcare. Apart from the pathology data, we aimed to utilize PALGA’s nationwide network to find and access the rich wealth of Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples for scientific use. We implemented the Dutch National TissueArchive Portal (DNTP) to utilize PALGA’s nationwide network for requesting FFPE tissue samples. The DNTP consists of (1) a centrally organized internet portal to improve the assessing, processing, harmonization, and monitoring of the procurement process, while (2) dedicated HUB-employees provide practical support at peripheral pathology departments. Since incorporation of the DNTP, both the number of filed requests for FFPE tissue samples and the amount of HUB-mediated support increased 55 and 29% respectively. In line, the sample procurement duration time decreased significantly (− 47%). These findings indicate that implementation of the DNTP improved the frequency, efficiency, and transparency of FFPE tissue sample procurement for research in the Netherlands. To conclude, the need for biological resources is growing persistently to enable precision medicine. Here, we access PALGA’s national, pathology network by implementation of the DNTP to allow for efficient, consistent, and transparent exchange of FFPE tissue samples for research across the Netherlands.

Adjunct diagnostic strategies in improving diagnostic yields in image-guided biopsies of musculoskeletal neoplasms-A cost-effectiveness analysis.

Routine use of adjunct intraprocedural fresh frozen biopsy (FFP) or point-of-care (POC) cytology at the time of image-guided biopsy can improve diagnostic tissue yields for musculoskeletal neoplasms, but these are associated with increased costs. This study aimed to ascertain the most cost-effective adjunctive test for image-guided biopsies of musculoskeletal neoplasms. This expected value cost-effectiveness microsimulation compared the payoffs of cost (2020 United States dollars) and effectiveness (quality-adjusted life, in days) on each of the competing strategies. A literature review and institutional data were used to ascertain probabilities, diagnostic yields, utility values, and direct medical costs associated with each strategy. Payer and societal perspectives are presented. One- and two-way sensitivity analyses evaluated model uncertainties. The total cost and effectiveness for each of the strategies were $1248.98, $1414.09, $1980.53, and 80.31, 79.74, 79.69 days for the use of FFP, permanent pathology only, and POC cytology, respectively. The use of FFP dominated the competing strategies. Sensitivity analyses revealed FFP as the most cost-effective across all clinically plausible values. Adjunct FFP is most cost-effective in improving the diagnostic yield of image-guided biopsies for musculoskeletal neoplasms. These findings are robust to sensitivity analyses using clinically plausible probabilities.

A Pilot Study to Determine the Utility of Automated Tissue Dissociator for Flowcytometry Based Evaluation of Hematolymphoid Tumor Tissue Biopsies.

Routine diagnostic biopsy tissue processing, conventional histology/immunohistochemistry (IHC) method is a multi-step and time consuming practice. With the advanced tissue dissociation protocols and panel designing, flow cytometric immunophenotyping (FCI) can be performed on diagnostic hematolymphoid tissue samples using single cell suspensions that economize steps and the time taken. Diagnostic tissue samples from lymph node, mediastinal mass, testicular biopsies and similar sites were dissociated using gentle MACS Octo-dissociator and FCI was performed thereafter. Oral tissue biopsy samples were also processed as a validation set for the protocol. 21 prospective tissue biopsy samples with suspected involvement by a known hematolymphoid neoplasm were processed and evaluated. These included B lymphoblastic lymphoma (n = 12), T lymphoblastic lymphomas (n = 3), Burkitts lymphoma (n = 3) and one case each of granulocytic sarcoma, Hodgkin lymphoma and granulomatous disease. Tissue FCI and IHC were found concordant with identified profile FCI obtained from blood/bone marrow analyses. FCI can produce a highly sensitive and reliable report, within hours, by processing fresh tumor tissue samples from suspected hematolymphoid malignancies. This method can be considered as an effective adjunct to IHC and can be applicable in routine clinical diagnostics, especially in cases that needs quick diagnosis and immediate clinical treatment.

Utility Of Non-Invasive Monitoring Of Circulating Tumor DNA At Diagnosis, Interim Therapy, and Relapse Of DLBCL Using High-Throughput Sequencing Of Immunoglobulin Genes

BackgroundRecent studies have shown limited utility of routine surveillance imaging for patients with diffuse large B-cell lymphoma achieving remission after R-CHOP (Thompson et al, ASCO 2013 #8503; Ghesquieres et al, ICML 2013 #226). Separately, response assessment using early interim PET-CT during R-CHOP has suboptimal accuracy. We hypothesized that non-invasive tumor burden monitoring using peripheral blood could have utility for diagnosis and monitoring of DLBCL. MethodsWe prospectively profiled two cohorts of patients with DLBCL at various stages in their disease, including at diagnosis, during various therapies, after achieving remission, and upon relapse or progression. Cohort1 patients were treated with curative intent at Stanford University with blood collected at multiple time points during follow-up. Cohort2 patients participated in a multi-center Austrialian Phase 2 study (ALLG NHL21), where patients with poor risk DLBCL as identified by residual disease on interim PET/CT after 4 R-CHOP cycles received early treatment intensification using R-ICE/ASCT; blood samples were collected before the 1st and after the 4thR-CHOP cycles. Tumor-derived clonotypic IgH and IgK sequences were defined in diagnostic tissues grossly involved with DLBCL, and then tracked using high-throughput sequencing of immunoglobulin genes (Faham et al 2012 Blood). ResultsWe successfully defined for 77% (30/39) of patients the tumor-specific immunoglobulin sequences required for non-invasive surveillance, with calibration success correlating with input tissue mass. Using 194 assays on 79 blood specimens from these patients, we detected disease in 75% of patients at diagnosis of DLBCL, in 18% at interim time-points during therapy, 0% during radiographic/clinical remissions, and 80% at relapse or disease progression. When considering radiographic/clinical follow-up, noninvasive monitoring had 0% false positive rate but 26% false negative rate, with the latter likely due to low tumor burden at time of phlebotomy. Disease burden detectable in the blood was significantly correlated between IgH and IgK assays, and between the cellular (leukocyte) and acellular (plasma) fractions (r=0.77, p=0.004). Strikingly, clonotypic IgH/IgK sequences were significantly more abundant in plasma than in circulating leukocytes, and identified exclusively in plasma in 5% of blood samples with available paired cellular/acellular fractions. This allowed more accurate disease detection and monitoring using plasma circulating tumor DNA than blood leukocytes, including in cases of radiographically defined isolated CNS involvement, and in histological transformation of FL. Within the limitations of this small study employing frequent surveillance imaging, we observed no significant lead time between detection of disease in the plasma and radiographic/clinical evidence of progression. ConclusionsNon-invasive surveillance of circulating tumor DNA has utility for tumor burden at diagnosis and relapse of DLBCL using high-throughput sequencing of immunoglobulin genes, with superior detection in blood plasma. The current assay has limited sensitivity at early interim time points during therapy. Disclosures:Kong:Sequenta Inc.: Employment. Faham:Sequenta, Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Abstract 364: The RAD51-FFPE test rapidly and reliably identifies homologous recombination deficient ovarian and endometrial carcinomas

Abstract Sensitivity to PARP inhibitors is related to tumor-specific defects in homologous recombination (HR) and extends beyond BRCA1/2-related deficiencies. Therefore, there is great interest in a robust method to identify HR-deficient (HRD) carcinomas in routine diagnostics. DNA-based assays that are developed to identify HRD are relatively complex, costly and time-consuming. As an alternative to DNA-based assays we developed the REcombination CAPacity (RECAP) test exploiting the accumulation of RAD51 protein after irradiation of fresh tumor tissue as a biomarker for HR proficiency. The RECAP test reliably identified HRD ovarian (OC) and endometrial (EC) carcinomas including those not related to BRCA1/2 deficiency. However, the implementation of the RECAP test in clinical diagnostics is hampered by dependency on ex vivo irradiation of fresh tumor tissue. We therefore explored the use of diagnostic formalin-fixed paraffin-embedded (FFPE) tumor tissue for the functional analysis of HR and aimed to determine the performance of RAD51 assessment on diagnostic FFPE blocks as compared to RECAP test. FFPE tumor tissue from tumors for which previously published RECAP scores were available (OC n = 49; EC n = 25) were subjected to a three-step quality assessment: 1) Tumor tissue quality analysis of hematoxylin and eosin stained slides by an expert pathologist, 2) Evaluation of yH2AX foci to confirm the presence of DNA damage and 3) Evaluation of the presence of a sufficient number of geminin positive (GMN+) tumor cells. When all quality criteria were met, the capacity of tumor cells to accumulate RAD51 protein at sites of endogenous DNA damage was analyzed using co-immunofluorescent staining. The RAD51-FFPE score was determined as the percentage of GMN+ cells with RAD51 foci. The performance of the RAD51-FFPE test was determined using corresponding RECAP scores. Seventy-four FFPE tumor tissues were subjected to the quality assessment. In total, 58 out of 74 (78%) met our tissue quality criteria. RAD51-FFPE scores correlated significantly with RECAP scores (p= <0.0001). Of the 16 tumors (including ten BRCA-related tumors) that were classified as HRD in the RECAP test (RECAP score ≤20% GMN+/RAD51+ cells), 15 showed a RAD51-FFPE score below 16%. Thirty-one out of 38 (82%) RECAP HR-proficient tumors (≥50% GMN+/RAD51+ cells) had RAD51-FFPE scores above 16%. The four tumors with RECAP scores in the HR intermediate group (20-50% GMN+/RAD51+ cells) showed RAD51-FFPE scores between 3-38%. We demonstrated that the RAD51-FFPE test on diagnostic FFPE tumor tissue is an attractive alternative to DNA-based tests to identify HRD in OC and EC. Although the optimal RAD51-FFPE threshold to identify HRD tumors needs to be established using larger cohorts with genomic and clinical trial outcome data, the RAD51-FFPE test is a promising candidate to serve as a low-cost routine diagnostic HRD test in the clinic. Citation Format: Lise M. van Wijk, Claire J. Kramer, Sylvia Vermeulen, Natalja T. ter Haar, Cor D. de Kroon, Marthe M. de Jonge, Katja N. Gaarenstroom, Harry Vrieling, Violeta Serra, Tjalling Bosse, Maaike P. Vreeswijk. The RAD51-FFPE test rapidly and reliably identifies homologous recombination deficient ovarian and endometrial carcinomas [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 364.

Influence of preoperative corticosteroid treatment on rate of diagnostic surgeries in primary central nervous system lymphoma: a multicenter retrospective study

BackgroundCorticosteroid therapy (CST) prior to biopsy may hinder histopathological diagnosis in primary central nervous system lymphoma (PCNSL). Therefore, preoperative CST in patients with suspected PCNSL should be avoided if clinically possible. The aim of this study was thus to analyze the difference in the rate of diagnostic surgeries in PCNSL patients with and without preoperative CST.MethodsA multicenter retrospective study including all immunocompetent patients diagnosed with PCNSL between 1/2004 and 9/2018 at four neurosurgical centers in Austria was conducted and the results were compared to literature.ResultsA total of 143 patients were included in this study. All patients showed visible contrast enhancement on preoperative MRI. There was no statistically significant difference in the rate of diagnostic surgeries with and without preoperative CST with 97.1% (68/70) and 97.3% (71/73), respectively (p = 1.0). Tapering and pause of CST did not influence the diagnostic rate. Including our study, there are 788 PCNSL patients described in literature with an odds ratio for inconclusive surgeries after CST of 3.3 (CI 1.7–6.4).ConclusionsPreoperative CST should be avoided as it seems to diminish the diagnostic rate of biopsy in PCNSL patients. Yet, if CST has been administered preoperatively and there is still a contrast enhancing lesion to target for biopsy, surgeons should try to keep the diagnostic delay to a minimum as the likelihood for acquiring diagnostic tissue seems sufficiently high.

Prognostic Value of P53 and Myc Protein Expression in Follicular Lymphomas in the PRIMA Trial in the Lysa Group

Introduction: Follicular lymphomas (FL) are indolent lymphomas without definitive criteria predicting their outcome. Previous immunohistochemical (IHC) studies showed controversial data about the prognostic value of IHC markers in FL. In order to clarify this issue, we evaluated p53 and Myc protein expression, 2 markers related to cancer cells and usually considered as correlated with a more aggressive behavior in many tumors including lymphomas. We used a large series of FL samples from rituximab-treated patients enrolled in the randomized PRIMA trial.Methods: Immunohistochemistry using p53 and Myc antibodies was performed on formalin fixed parafin embedded diagnostic tissue micro arrays (TMA) of FL samples of 253 patients of the PRIMA trial. The IHC results were quantified by a semi-quantitative method using the percentage of cells stained on each TMA spot. The results were statistically compared with other clinico-biological parameters. For the 2 variables, different cut-offs were studied on progression free survival (PFS) and overall survival (OS).Results: As to p53 protein expression, a cut-off >20% increased significantly the risk of poor PFS (HR=1.67 [1.14-2.45], p=0.008) but was not significant for OS. As to Myc protein expression, a cut-off ≥ 10% was close to be significant (p=0.056) of poor PFS but was not significant for the OS. In a multivariate analysis, only p53 remained significant (HR=1.53 [1.002-2.34], p=0.048) for poor PFS. There was no correlation between the level of p53 and Myc protein expression and the histological grade in our series. When the interaction between the two markers was compared, it was not significantly correlated.Conclusion: These results suggest that IHC p53 protein expression in this series of 253 patients has a significant prognostic value in FL patients. More than 20% p53 positive cells indicated a worse PFS , but was not significantly associated with a worse OS. It could be then recommended to incorporate p53 IHC in routine diagnostic practice. These results are currently under validation on an independent series of FL patients DisclosuresFeugier:Roche: Consultancy, Honoraria, Research Funding. Morschhauser:Gilead: Consultancy; Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Servier: Consultancy. Salles:MSD: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Kite: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Electronic Worklist Improves Timeliness of Screening Mammogram Interpretation in an Urban Underserved Population

ObjectivesTo evaluate the impact of an electronic workflow update on screening mammography turnaround time and time to diagnostic imaging for mammography performed on our urban mobile mammography van and at an urban community health center. MethodPrior to 10/15/2019, screening exams for the mammography van and urban community health center were made available for interpretation to a single designated radiologist via a manually generated paper list. On 10/15/2019, screening exams were routed electronically onto PACS for any breast radiologist across our Network to interpret. Screening mammogram turnaround time (defined as time form image acquisition to report finalization), time to diagnostic imaging, and time to tissue sampling were collected for pre- and post-implementation periods (6/1-9/30/2019 and 11/1/2019-2/29/2020, respectively) and compared via student t-test and statistical process control analyses. ResultsThe number of screening exams in the pre- and post-implementation periods were 851 and 728 exams, respectively. Patients were predominately Black and/or African American (400/1579, 25%), non-English speaking (858/1579, 54%) and insured by Medicaid (751/1579, 48%). After implementation of the electronic workflow, turnaround time decreased from 101.0 to 36.4 hours (63.9%, P <0.001) and statistical process control analyses showed sustained decrease in mean turnaround time. However, mean time to diagnostic imaging and tissue sampling were unchanged after implementation (39 vs 45, days; P = 0.330 and 43 vs 59; P = 0.187, respectively). ConclusionElectronic workflow management can reduce screening mammography turnaround time for underserved populations, but additional efforts are warranted to improve time to imaging follow-up for abnormal screening mammograms.

PCN91 Patient Responsible Out-of-Pocket Costs for Solitary Pulmonary Nodule Biopsy in Lung Cancer Patients

Over the last few decades, dynamic changes in the payer landscape have resulted in increasing patient responsible out-of-pocket costs (PROOPC). As such, little is known about these types of costs for patients undergoing diagnostic biopsy for suspicious pulmonary nodules in the U.S. This study seeks to describe the spectrum of PROOPC for diagnostic tissue sampling for suspicious pulmonary nodule with an ultimate diagnosis of lung cancer.

Circular RNAs Are Promising Biomarkers in Liquid Biopsy for the Diagnosis of Non-small Cell Lung Cancer.

The high incidence and mortality of lung cancer make early detection of lung cancer particularly important. At present, the diagnosis of lung cancer mainly depends on diagnostic imaging and tissue biopsy. However, current diagnostics are not satisfactory owing to the low specificity and inability of multiple sampling. Accumulating evidence indicates that circular RNAs (circRNAs) play a critical role in cancer progression and are promising cancer biomarkers. In particular, circRNAs are considered novel specific diagnostic markers for non-small cell lung cancer (NSCLC). Liquid biopsy is an important method in the early diagnosis of cancer due to its high sensitivity and specificity, as well as the possibility of performing multiple sampling. circRNAs are stably present in exosomes and sometimes become part of circulating nucleic acids, making them ideal for liquid biopsy. In this review, we summarize the advances in the research on circRNAs in NSCLC, and also highlight their potential applications for NSCLC detection.

ID: 3523078 ENDOSCOPIC ULTRASOUND CHARACTERISTICS OF PANCREATIC NEUROENDOCRINE TUMORS

Pancreatic neuroendocrine tumors (pNETs) are rare, comprising 1-2% of all pancreatic neoplasms, but the incidence is increasing. Endoscopic ultrasound (EUS) can both image and obtain diagnostic tissue, allowing for pathology-guided treatment.

Cancer pathways analysis and correlation with survival in patients with advanced stage non-small cell lung cancer treated with PD-1 inhibitor.

e21007 Background: Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein-1 (PD-1) have demonstrated activity in the first-line setting of advanced stage non-small cell lung cancer (NSCLC); however, a proportion of patients progresses to immunotherapy, hence the definition of prognostic and predictive factors is of interest. Potentially, the expression pattern of gene sets can serve as clinical indicator. We hereby present data from a pilot study of a larger project of gene expression analysis in patients with advanced NSCLC treated with ICIs, to explore the baseline expression level of single and grouped-in-pathways genes and to draw correlations with the overall survival (OS). Methods: We performed a retrospective transcriptome analysis of diagnostic cancer tissue from 14 consecutive patients with advanced stage NSCLC with PD-L1 expression &gt; 50% treated with anti-PD-1 pembrolizumab as first-line. Two hundred ng of RNA was profiled by Nanostring technology using the human nCounter® PanCancer IO 360™ Panel, that includes 770 genes from 14 different immune cell types, common checkpoint inhibitors, Cancer-Testis antigens, and genes covering both the adaptive and innate immune response. Data analysis was performed by nCounter Advanced Analysis (version 2.0.134) plug in for nSolver Software and R package. Results: The median age of patients was 71 years (range 59-88), most were males (78%) with an ECOG performance status ranging from 0 to 1 (86%). All patients were smokers or former smokers. Seven out of 14 patients (50%) had a partial/complete response as best response, whereas the remaining population reported disease progression, 3 of whom died before the first CT-scan evaluation. The median OS was 12 months (range 1–40). The 770-tumor/immune gene expression profiling reported 11 genes (6 overexpressed and 5 down-modulated in patients with a survival under the median), which were significantly associated with poor outcome ( p-value &lt; 0.01). Notably, when we adjusted the expression data to the site of biopsy (tumor tissue vs. neoplastic lymph node), we identified a 27-gene signature ( ATG5, BMI1, CASP1, CCL11, CCL8, CD164, CD86, CD97, EGR1, FADD, FOS, HLA-DQA1, HLA-DQB1, IFITM1, IRF3, LY96, MCAM, NFKBIA, RRAD, SMAD2, STAT6, TLR3, TNFAIP3, TNFRSF1A, TOLLIP, VEGFC, and YTHDF2) able to separate patients with a survival below or above the median. The in-silico prediction of this signature showed that the antigen processing pathway (HLA-DQA1, HLA-DQB1), already described as an immune checkpoint resistance mechanism, was significantly down-modulated in long survivors. Conclusions: By a multiplexed analysis of gene expression through messenger RNA digital detection, we identified a gene set that, if confirmed, might have a prognostic value in patients with advanced stage NSCLC with PD-L1 expression &gt;50% treated with pembrolizumab as first-line.

Type of tissue biopsy and outcomes in diffuse large B-cell lymphoma (DLBCL).

e13569 Background: Progress in understanding the molecular biology of DLBCL has led to development of complex molecular classifications that rely on sequencing methods. These molecular clusters are defined by activation of distinct pathways and may aid in selecting targeted therapy. In the molecular era, tissue requirements in clinical trials have increased to ensure sufficient tissue for molecular testing, potentially resulting in bias for enrollment of patients with larger excisional biopsies (EB). We examined the impact of tissue biopsy method on outcomes of DLBCL in a prospective observational study. Methods: Consecutive adult patients with DLBCL within 9 months from their initial diagnosis were enrolled into the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (SPORE). Demographics, clinical variables, type of tissue biopsy (EB vs. core needle biopsy (CNB)) for initial diagnosis and initial treatment were recorded at baseline. Pts were contacted every 6 months from the date of diagnosis for first 3 years and then annually thereafter. Study objectives were event free survival (EFS) and overall survival (OS) by tissue biopsy method. Results: A total of 1061 patients with newly diagnosed DLBCL, from 2002 to 2015, were included. The table lists baseline characteristics of the cohort. 593 (56%) pts underwent EB and 468 (44%) underwent CNB for initial diagnosis. A significantly higher proportion of patients receiving CNB had performance status &gt;=2, advanced stage, high risk disease by international prognostic index (IPI), abnormal lactate dehydrogenase. Median time from diagnosis to treatment initiation (DTI) was significantly shorter in the CNB group (13 days) than EB group (19 days). 2-year EFS (60% vs 75%, HR 0.75 (0.6-0.9), p &lt;0.01) was significantly lower in CNB than EB group. There was a trend towards lower OS (75% vs 80%, HR: 0.8 (0.6-0.95), p =0.049) in CNB than EB group. Conclusions: Patients undergoing CNB are more likely to have higher risk disease, shorter DTI and survival compared to those undergoing EB. A need for large amount of diagnostic tissue in biomarker driven clinical trials may result in disproportional exclusion of high risk DLBCL pts who have inferior outcomes after standard treatment and could potentially benefit from novel agents, resulting in overperformance of the control arm. The need for tissue must be carefully balanced against resulting selection bias.[Table: see text]

Copy number profiles of primary tumors for risk stratification of advanced prostate cancer: A biomarker study embedded in the multicenter STAMPEDE trial.

5021 Background: Men with advanced hormone-sensitive prostate cancer (HSPC) starting long term androgen deprivation therapy (ADT) follow a highly variable clinical course. Treatment intensification with docetaxel or AR targeted therapies improves outcomes but there is a risk of overtreatment, especially in non-metastatic (M0) or metastatic (M1) low volume disease. We established a framework for biomarker evaluation in the STAMPEDE trial. We aimed to evaluate the feasibility and clinical utility of assessing the burden of copy number (CN) aberrations in newly diagnosed advanced HSPC. We hypothesised that increased percentage genome altered (PGA) would associate with higher disease burden and worse prognosis. Methods: We implemented a scalable strategy using low coverage whole genome sequencing (lpWGS) of formalin fixed paraffin embedded (FFPE) diagnostic core biopsies from STAMPEDE participants randomised to the standard of care ADT arm, between 2005 and 2016. Tissue was retrieved from 136 trial sites. 315 cases were randomly selected, aiming for a biomarker population of 300, anticipating an assay failure rate ̃5%. We defined 40% as the minimum histopathologically determined tumor cellularity (TC) for inclusion. We performed a survival analysis investigating PGA at diagnosis as a continuous measure with fractional polynomial specification in Cox models adjusting for disease burden, Gleason grade, pre-ADT PSA (log-transformed), age at randomisation and TC. We pre-specified that all hypothesis tests required evidence at the 5% significance level to consider rejecting the null hypothesis. Results: We successfully CN profiled 300/315 cases. There were no significantly different baseline clinico-pathological features between the full trial comparison n = 3106 and final biomarker population n = 300, 290/300 cases were de novo presentations. PGA in the core with highest Gleason grade and TC was median 18% (range 0%-75%; n = 300). PGA was significantly higher in M1 (n = 169) compared to M0 (n = 131) cases (median: 21% vs 14%; p = 0.00006). 284/300 were subclassified by disease burden into M0 node negative and node positive, and M1 low and high volume. PGA was significantly associated with increased disease burden (p = 0.00002). Increased PGA was significantly and non-linearly associated with an increased hazard of failure-free survival (p = 0.004), progression-free survival (p = 0.002), metastatic progression-free survival (p = 0.003), overall survival (p = 0.045) and prostate cancer-specific survival (p = 0.011). Conclusions: Evaluation of the burden of CN aberrations in archival, poor quality FFPE diagnostic tissue from men randomised in the STAMPEDE trial is feasible using lpWGS and has potential clinical utility to identify better prognosis advanced HSPC patients, who may not require treatment intensification.

Computed Tomography-Guided Transthoracic Needle Biopsy: Predictors for Diagnostic Failure and Tissue Adequacy for Molecular Testing.

Background: Adequate and representative tissue from lung tumor is important in the era of precision medicine. The aim of this study is to identify detailed procedure-related variables and factors influencing diagnostic success and tissue adequacy for molecular testing in CT-guided TTNB.Methods: Consecutive patients undergoing CT-guided TTNB were retrospectively enrolled between January 2013 and May 2020. Multivariate analysis was performed for predictors for diagnostic accuracy and tissue adequacy for molecular testing. Logistic regression was used to identify risk factors for procedure-related complications.Results: A total of 2,556 patients undergoing CT-guided TTNB were enrolled and overall success rate was 91.5% (2,338/2,556). For lung nodules ≤3 cm, predictors for diagnostic success included coaxial needle use [OR = 0.34 (0.16–0.71), p = 0.004], CT scan slice thickness of 2.5 mm [OR = 0.42 (0.15–0.82), p = 0.011] and additional prefire imaging [OR = 0.31 (0.14–0.68), p = 0.004]. For lung tumor >3 cm, ground glass opacity part more than 50% [OR = 7.53 (2.81–20.23), p < 0.001] or presence of obstructive pneumonitis [OR = 2.31 (1.53–3.48), p < 0.001] had higher risk of diagnostic failure. For tissue adequacy, tissue submitted in two cassettes (98.9 vs. 94.9%, p = 0.027) was a positive predictor; while male (5.7 vs. 2.5%, p = 0.032), younger age (56.61 ± 11.64 vs. 65.82 ± 11.98, p < 0.001), and screening for clinical trial (18.5 vs. 0.7%, p < 0.001) were negative predictors.Conclusions: Using a coaxial needle, with thin CT slice thickness (2.5 mm), and obtaining additional prefire imaging improved diagnostic success, while obtaining more than two tissue cores and submitting in two cassettes improved tissue adequacy for molecular testing.