Factor In Diffuse Large B-cell Lymphoma Research Articles

Clinicopathological differences in MYC and BCL2 protein expression between primary extranodal and nodal diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) exhibits clinical, genetic, and immunohistochemical heterogeneity. However, the differences between primary extranodal or nodal DLBCL and double-expressor lymphoma (DEL), which is characterized by high MYC and BCL2 expression, remain unclear. This study aimed to elucidate the clinicopathological features, response to therapy, and clinical outcomes of primary extranodal (n=61) and nodal (n=128) DLBCL. Patients with primary nodal DLBCL had higher BCL2 expression than those with extranodal DLBCL (p=0.048), with high MYC expression and DEL as poor prognostic factors. Conversely, in patients with primary extranodal DLBCL, high BCL2 expression, low BCL6 expression, non-germinal center B-cell-like type, and DEL indicated poor prognosis. DEL was significantly associated with progression free survival and overall survival in patients with primary extranodal DLBCL (p=0.014 and p=0.021, respectively) but not in patients with primary nodal DLBCL (p=0.37 and p=0.084, respectively). Our findings highlight primary extranodal DEL as a strong adverse prognostic factor in DLBCL.

Abstract PO-015: The RNA helicase DDX21 cooperates with ETS1 and FLI1 in cell cycle regulation, immune evasion and small nucleolar RNA processing to sustain the survival of DLBCL cells

Abstract Introduction.The ETS1 and FLI1 transcription factors are both located in the 11q24.3 region, which is commonly amplified in 25% of diffuse large B cell lymphomas (DLBCL) (Bonetti et al, 2013) and largely co-regulate a series of genes involved in B-cell signaling, differentiation and cell cycle (Priebe et al, 2020; Sartori et al, 2021). While FLI1 is expressed at a higher level in DLBCL of the germinal center B-cell (GCB) type than in the activated B-cell-like (ABC) DLBCL, ETS1 is more expressed in the latter subgroup. We and others have reported preclinical anti-tumor activity in lymphomas and other tumors with small molecules blocking the binding of ETS factors and RNA helicases (Erkizan et al, 2009; Spriano et al, 2019). Methods.To explore interaction partners, protein precipitation was conducted utilizing streptavidin beads to capture strep-tagged ETS1 in the ABC DLBCL cell line, HBL-1, followed by Liquid Chromatography tandem Mass Spectrometry (LC-MS/MS). Shotgun proteomics analysis identified biologically relevant ETS1 protein interactors, with a spectral count above four, that were validated by normal and reverse co-immunoprecipitation experiments. Transcriptome analysis was done via RNASeq and smallRNASeq after DDX21 siRNAs silencing in four DLBCL cell lines, two derived from ABC (HBL1 and U2932) and two from GCB (OCI-Ly1 and VAL). Direct targets were validated by DDX21 chromatin immunoprecipitation (ChIP). Results. The ETS1 interactors included proteins associated with RNA processing. Among these, we focused on the novel interactor DDX21, an RNA helicase also regulated by pETS1 (Chung et al, 2023) and FLI1 (Sartori et al, 2021). DDX21 was found differentially expressed between GCB and ABC DLBCL, with higher expression in the latter (P<0.001). When we silenced DDX21 with siRNAs, toxicity was seen in ABC cell lines. To better characterize the role of DDX21 as a transcriptional factor in DLBCL we obtained RNASeq transcriptome after DDX21 silencing. Transcriptional profiling and functional annotation of transcripts regulated by DDX21 revealed genes coding proteins involved in cell cycle (FDR <0.001), ribosomes (FDR <0.001) and immune evasion (FDR <0.001). Based on the role of DDX21, smallRNAseq was also performed and miRNAs of some members of the let7 family (hsa-let-7d, hsa-let-7e and hsa-let-7f) were found downregulated by DDX21, together with miR-532. Among the upregulated miRNAs miR-222 and miR-155 were the most interesting. Different snoRNAs were also found deregulated, SNORA37 was further validated as a DDX21 upregulated direct target by RNA and ChIP qPCR. Conclusions. In ABC DLBCL, ETS1 interacts with proteins involved in spliceosome and in ribosome biogenesis, including DDX21. More expressed in ABC than GCB DLBCL, DDX21 appears essential for the survival of ABC lymphoma cells by regulating cell cycle, RNA processing and immune evasion. Several miRNAs and snoRNAs were found deregulated by DDX21. The interaction between ETS1 and DDX21 offers an additional therapeutic opportunity against DLBCL cells. Citation Format: Giulio Sartori, Valdemar Priebe, Luciano Cascione, Elaine Y.L. Chung, Mélanie Favre-Juilland, Sara Napoli, Alberto Arribas, Stefano Giuffrida, Andrea Rinaldi, Margot Thome Miazza, Francesco Bertoni. The RNA helicase DDX21 cooperates with ETS1 and FLI1 in cell cycle regulation, immune evasion and small nucleolar RNA processing to sustain the survival of DLBCL cells [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PO-015.

Tumor-Infiltrating Normal B Cells Revealed by Immunoglobulin Repertoire Clonotype Analysis Are Highly Prognostic and Crucial for Antitumor Immune Responses in DLBCL.

Tumor-infiltrating B lymphocytes (TIL-B) have demonstrated prognostic and predictive significance in solid cancers. In this study, we aimed to distinguish TIL-Bs from malignant B-cells in diffuse large B-cell lymphoma (DLBCL) and determine the clinical and biological significance. A total of 269 patients with de novo DLBCL from the International DLBCL R-CHOP Consortium Program were studied. Ultra-deep sequencing of the immunoglobulin genes was performed to determine B-cell clonotypes. The frequencies and numbers of TIL-B clonotypes in individual repertoires were correlated with patient survival, gene expression profiling (GEP) data, and frequencies of DLBCL-infiltrating immune cells quantified by fluorescent multiplex IHC at single-cell resolution. TIL-B abundance, evaluated by frequencies of normal B-cell clonotypes in the immunoglobulin repertoires, remarkably showed positive associations with significantly better survival of patients in our sequenced cohorts. DLBCLs with high versus low TIL-B abundance displayed distinct GEP signatures, increased pre-memory B-cell state and naïve CD4 T-cell state fractions, and higher CD4+ T-cell infiltration. TIL-B frequency, as a new biomarker in DLBCL, outperformed the germinal center (GC) B-cell-like/activated B-cell-like classification and TIL-T frequency. The identified TIL-B-high GEP signature, including genes upregulated during T-dependent B-cell activation and those highly expressed in normal GC B cells and T cells, showed significant favorable prognostic effects in several external validation cohorts. TIL-B frequency is a significant prognostic factor in DLBCL and plays a crucial role in antitumor immune responses. This study provides novel insights into the prognostic determinants in DLBCL and TIL-B functions with important therapeutic implications.

Analysis of endoplasmic reticulum stress-related gene signature for the prognosis and pattern in diffuse large B cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in adults. This study aimed to determine the prognostic significance of endoplasmic reticulum (ER) stress-related genes in DLBCL. ER stress-related genes were obtained from the molecular signatures database. Gene expression data and clinical outcomes from the gene expression omnibus and TCGA datasets were collected, and differentially expressed genes (DEGs) were screened out. Gene ontology enrichment analysis, the kyoto encyclopaedia of genes and genomes pathway analysis, and geneset enrichment analysis were used to analyse the possible biological function of ER stress-related DEGs in DLBCL. Protein–protein interaction network construction using the STRING online and hub genes were identified by cytoHubba on Cytoscape software. The significant prognosis-related genes were screened, and the differential expression was validated. The immune microenvironment assessment of significant genes were evaluated. Next, the nomogram was built using univariate and multivariate Cox regression analysis. 26 ER stress-related DEGs were screened. Functional enrichment analysis showed them to be involved in the regulation of the endoplasmic reticulum mainly. NUPR1 and TRIB3 were identified as the most significant prognostic-related genes by comparison with the GSE10846, GSE11318, and TCGA datasets. NUPR1 was correlated with a good prognosis and immune infiltration in DLBCL; on the other hand, high expression of TRIB3 significantly correlated with a poor prognosis, which was an independent prognostic factor for DLBCL. In summary, we identified NUPR1 and TRIB3 as critical ER stress-related genes in DLBCL. NUPR1 might be involved in immune infiltration in DLBCL, and TRIB3 might serve as a potential therapeutic target and prognostic factor in DLBCL.

Lenalidomide maintenance fails to overcome the unfavourable prognosis of low NK-cell counts in rituximab-chemotherapy responsive elderly DLBCL patients: A LYSA group study.

Low baseline NK-cell counts (NKCCs) in patients with diffuse large B-cell lymphoma (DLBCL) are associated with a poor prognosis. The REMARC phase III trial (NCT01122472) showed that lenalidomide maintenance prolonged PFS in rituximab-chemotherapy responders. We conducted a REMARC ancillary study analysing the impact of lenalidomide maintenance on the prognostic value of low NKCCs. Blood samples from 335 elderly French patients enrolled in the REMARC trial were analysed by flow cytometry to obtain NKCCs at diagnosis (n = 220), at randomization (n = 186) and/or six months after randomization (n = 184). Baseline NKCCs < 100 cells/μl were associated with shorter PFS and OS (HRs=[2.2 (1.4, 3.3), p < 0.001] and [2.8 (1.7, 4.5), p < 0.001], respectively), independently of aaIPI. In a competing risk analysis, low NKCCs at baseline were associated with a higher risk of relapse/progression (p=0.0025), but not of death without progression (p=0.33). Lenalidomide did not affect the prognosis value of low baseline NKCCs (p =0.6349). Similar results were obtained for low NKCCs at randomization. Our results demonstrate that low NKCCs at baseline and post rituximab-chemotherapy are robust prognostic factors in DLBCL and reveal that lenalidomide has no impact on this parameter. Other therapeutic strategies aiming at improving NK-cell function could improve outcomes in DLBCL.

Combination Anti-PD1 Antibody and Rituximab Followed By R-CHOP for Elderly Patients with Newly Diagnosed DLBCL: Analysis of the Phase II TREND Trial

Background: Patients with diffuse large B-cell lymphoma (DLBCL) in the elderly face challenges in treatment due to comorbidities and poor tolerance of chemotherapy. Age >60 years is an unfavorable risk factor in DLBCL in the International Prognostic Index (IPI) system. Besides, increased proportion of ABC/non-GCB subgroups, complex molecular features also lead to unfavorable prognosis with distinct biological or immune microenvironment features in elderly patients. Although clinical benefit of single-agent anti-PD-1 antibody in DLBCL was not obvious, pre-use anti-PD-1 antibody as first-line may be an opportune for elderly DLBCL. Toripalimab, a recombinant, humanized programmed death receptor-1 (PD-1) monoclonal antibody has been approved by the NMPA for the treatment of various cancers. Methods: Patients aged 60-85 years, ECOG 0-2 with untreated DLBCL or grade 3b follicular lymphoma and at least one measurable or evaluable lesion were enrolled. This study consisted of a phase 1b (Toripalimab dose escalation) followed by a Phase 2 expansion portion. In the phase Ib, a standard "3+3" design was utilized to identify the MTD, DLT and recommended phase 2 dosage (RP2D) of Toripalimab.In phase 2, patients received 2 cycles of Toripalimab (RP2D) plus Rituximab (375mg/m2) every 3 weeks. They allowed to accept two additional cycles of Toripalimab plus Rituximab (To-Ri) if they obtained complete response (CR) after the first 2 cycles. To-Ri followed by R-CHOP (21) up to 6 cycles without Toripalimab then Toripalimab (RP2D) maintenance 6 cycles (q 30 days) after CR or CMR post R-CHOP. All cases more than 75-year-old received R-miniCHOP. The primary endpoints were objective response rate (ORR) based on Lugano 2016 criteria and clinical benefit rate. Secondary endpoints were progression-free survival (PFS), overall survival (OS) and safety. Adverse events (AEs) were defined according to CTCAE 5.0. This trial was registered at ClinicalTrials.gov (NCT04058470). Results: From December 2020 to July 2022, 37 eligible patients were enrolled. Median age 67 years (range, 60-83), 16 (43.2%) male, 20 (54.1%) patients with stage III/IV, 27(73.3%) patients with extranodal disease, 8 (21.6%) patients with IPI score ≥ 3 points, and non-GCB(n=25), double expression (DEL, n=7), EBV+DLBCL(n=5), double/triple hit lymphoma (DHL/THL, n=2). In phase Ib, no MTD or DLT events were observed, RP2D of Toripalimab was 240mg. Of 34 response evaluable patients, 14 patients completed To-Ri×4, 26 (59.1%) achieved response including 15 (44.1%) patients with CR post To-Ri treatment. Key responded to To-Ri including non-GCB (81.8%, n=18), GCB (58.3%, n=7), EBV+DLBCL (50%, n=2), DEL (87.5%, n=7), DHL/THL (100%, n=2), primary gastrointestinal tract involved (75%, 6/8) and primary nasal involved (87.5%, 7/8). Five patients are still under treatment, ORR and CR post R-CHOP were 100% (32/32) and 87.5% (28/32). With a median follow-up of 8.2 months, estimated 1-year PFS and were 81.2% and 88.4%. Thirty-six (97.3%) patients reported treatment-related AEs (TRAEs). The most frequently observed (≥10%) TRAEs were abnormal liver function (43.2%), anemia (43.2%), lymphopenia (32.4%), neutropenia (27.0%), hypothyroidism (21.6%), nausea (18.5%). This clinical trial is still on going. Conclusion: Toripalimab plus Rituximab as a first-line treatment then followed by R-CHOP yielded high CR rate and manageable toxicities in elderly with newly diagnosed DLBCL, especially for patients with extranodal disease and high grade lymphoma. This therapeutic strategy deserves further clinical investigation. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Metabolic Tumor Volume Predicts Outcomes in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma Treated with Loncastuximab Tesirine in the Lotis-2 Trial

Introduction: Identification of new predictive biomarkers in relapsed/refractory (rel/ref) diffuse large B-cell lymphoma (DLBCL) is essential for individualized treatment selection and optimization of outcomes. Metabolic tumor volume (MTV) is a strong prognostic factor in DLBCL, though, its value in patients treated with loncastuximab tesirine has not yet been explored. We investigated the impact of quantitative PET/CT data on treatment response and survival in patients treated with this compound. Methods: In this post-hoc analysis, we reviewed screening PET/CT images of patients enrolled in the LOTIS-2 trial (NCT03589469). MTV was obtained by adding the metabolic volumes of all individual lesions using the 41% of SUVmax threshold. Total lesion glycolysis (TLG) was calculated as the product of MTV and SUVmean for all individual lesions. SUVmax, MTV and TLG were calculated on screening PET/CT images by a nuclear medicine (NM) radiologist using Hermes Affinity Viewer software. Values calculated by the first reader were independently confirmed by a second NM reader and a deep learning-aided automated method (Kuker R, et al. SNMMI 2022). We tested if these quantitative metrics presented as continuous variables, in the original scale and as log2-transformed data, could predict treatment response, event-free survival (EFS) and overall survival (OS). We also used an outcome-oriented method to determine cutpoints (c) as markers for risk-stratification. Internal validation based on bootstrap was performed to evaluate predictive performance of identified cutpoints. Optimism was calculated using mean of differences between AUC of bootstrap sample and AUC of original dataset. The optimism-corrected AUCs (ocAUC) was considered to take account of model overfitting. The goals of this study were to assess the impact of quantitative PET/CT metrics to predict complete metabolic response (CMR) (primary endpoint) and survival (secondary endpoints) after loncastuximab tesirine treatment. We grouped together patients with no metabolic response (NMR), disease progression (PD), and not evaluable (NE) due to similar survival. Results: At the time of analysis, PET/CT images were available for review in 118 of the 145 patients enrolled. We first investigated the predictive value of PET/CT metrics to determine CMR. Patients achieving CMR exhibited significantly lower values in SUVmax, MTV and TLG (Table 1). We identified high interobserver agreement in MTV values. As continuous variables, log2(SUVmax), log2(MTV) and log2(TLG) were predictive of failure to achieve CMR (1-unit increase odds ratio [OR]= 1.06, 95%CI 1.01-1.10, P=0.008, AUC=0.666; OR=1.52, 95%CI 1.22-1.89, P=0.002, AUC=0.744; and OR=1.49, 95%CI 1.23-1.80, P<.0001, AUC=0.758; respectively). We identified the cutpoints of SUVmax ≥17 (OR=3.94, 95%CI 1.62-9.58, P=0.002, ocAUC= 0.653), MTV ≥43ml (OR=6.82, 95%CI 2.51-18.51, P=0.0002, ocAUC=0.716) and TLG ≥434 (OR=6.84, 95%CI=2.61-17.89, P<.001, ocAUC=0.720) as predictors of failure to achieve CMR. Next, we assessed the association of PET/CT metrics with EFS and OS. Median EFS & OS (months) by treatment response were: CMR= not reached (NR) (95%CI 14.2-NR) & NR (95%CI 16.2-NR); PMR= 3.4 (95%CI 2.8-7.4) & 11.2 (95%CI 7.1-16.4); NMR/PD= 1.4 (95%CI 1.3-2) & 5.8 (95%CI 2.6-6.9); (P<.0001) respectively. Again, log2(MTV) (hazard ratio (HR)=1.28, 95%CI 1.15-1.42, P<.0001 and HR=1.38, 95%CI 1.22-1.55, P<.0001) and log2(TLG) (HR=1.21, 95%CI 1.11-1.32, P<.0001 and HR=1.29, 95%CI 1.17-1.42, P<.0001) predicted shorter EFS and OS, respectively. log2(SUVmax) predicted only shorter OS (HR=1.02, 95%CI 1.00-1.03, P=0.033). We observed SUVmax ≥18 (EFS: HR=1.65, 95%CI 1.06-2.55, P=0.027 & OS: HR=1.7, 95%CI 1.06-2.75, P=0.029), MTV ≥68ml (EFS: HR=3.02, 95%CI 1.94-4.7, P<.0001 & OS: HR=3.26, 95%CI 2.05-5.19, P<.0001) and TLG ≥479 (EFS: HR=2.34, 95%CI 1.52-3.6, P=.0001 & OS: HR=2.46, 95%CI 1.54-3.91, P=.0001) as cutpoints associated with shorter survival. Conclusion: In the present analysis we demonstrated the predictive impact of PET/CT data in rel/ref DLBCL retaining its risk-stratification power as continuous and categorical variables. MTV is an imaging biomarker extracted from routine PET/CT scans and enables individualized treatment selection identifying those patients that will benefit the most from loncastuximab tesirine. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

KIF23 is a potential biomarker of diffuse large B cell lymphoma: Analysis based on bioinformatics and immunohistochemistry.

Diffuse Large B Cell Lymphoma (DLBCL), the most common form of blood cancer. The genetic and clinical heterogeneity of DLBCL poses a major barrier to diagnosis and treatment. Hence, we aim to identify potential biomarkers for DLBCL.Differentially expressed genes were screened between DLBCL and the corresponding normal tissues. Kyoto Encyclopedia of Genes and Genomes and Gene oncology analyses were performed to obtain an insight into these differentially expressed genes. PPI network was constructed to identify hub genes. survival analysis was applied to evaluate the prognostic value of those hub genes. DNA methylation analysis was implemented to explore the epigenetic dysregulation of genes in DLBCL.In this study, Kinesin family member 23 (KIF23) showed higher expression in DLBCL and was identified as a risk factor in DLBCL. The immunohistochemistry experiment further confirmed this finding. Subsequently, the univariate and multivariate analysis indicated that KIF23 might be an independent adverse factor in DLBCL. Upregulation of KIF23 might be a risk factor for the overall survival of patients who received an R-CHOP regimen, in late-stage, whatever with or without extranodal sites. Higher expression of KIF23 also significantly reduced 3, 5, 10-year overall survival. Furthermore, functional enrichment analyses (Kyoto Encyclopedia of Genes and Genomes, Gene oncology, and Gene Set Enrichment Analysis) showed that KIF23 was mainly involved in cell cycle, nuclear division, PI3K/AKT/mTOR, TGF-beta, and Wnt/beta-catenin pathway in DLBCL. Finally, results of DNA methylation analysis indicated that hypomethylation in KIF23's promoter region might be the result of its higher expression in DLBCL.The findings of this study suggested that KIF23 is a potential biomarker for the diagnosis and prognosis of DLBCL. However, further studies were needed to validate these findings.

Cell of Origin Based on Hans’ Algorithm as Prognostic Factor in Diffuse Large B-Cell Lymphoma: A Clinicopathologic and Survival Study

Background: Diffuse Large B-Cell Lymphoma (DLBCL) has been classified based on Cell of Origin (COO) into Germinal Center B-cell (GCB) and Non-Germinal Center B-cell (Non-GCB). The practical application of this concept by immunohistochemistry (IHC)-based subtyping with Hans’ algorithm and its role as a prognostic factor has been widely investigated with conflicting results. Moreover, the recent deeper molecular characterizations of DLBCL have been another challenges for this approach to remain as a prognostic factor. Objective: To determine the prognostic value of COO by IHC-based subtyping with Hans’ algorithm for DLBCL. Materials and Methods: This was a single-center retrospective analysis including DLBCL cases diagnosed in 2014-2019 from Dr. Sardjito Hospital, Yogyakarta, Indonesia. Hans’ algorithm with CD10, BCL6, and MUM1 were used. The two subtypes were compared in terms of clinicopathological features and 3 years overall survival. Results: Seventy patients were included in this study. Non-GCB was predominant than GCB 74.3% vs 25.7%, with the ratio of 2.8:1. No statistical difference in the clinicopathological features from both subtypes in terms of age, gender, Ann Arbor stadium, ECOG performance status, extra-nodal involvement, and LDH level. Ann Arbor stadium and ECOG showed significant prognostic value for patients outcome with multivariate analysis (OR 3.64; 95%CI 0.18-0.61; p=0.001) and (OR 2.68; 95%CI 0.11-0.77; p=0.009). Survival analysis based on COO did not show significant difference between GCB and non-GCB subtypes (log rank=0.46). Further analysis based on COO and the use of rituximab showed better OS in the two subtypes than without rituximab although not significant (log rank=0.67). Conclusion: The role of COO with Hans’ algorithm as prognostic factor in DLBCL is not confirmed in this study. Some related factors may be the addition of rituximab and the recent molecular characterization of DLBCL which covered a more subtle classification of the disease beyond GCB and non-GCB subtypes.

Defining Diffuse Large B-Cell Lymphoma Immunotypes by CD8+ T Cells and Natural Killer Cells.

Background There is a poor prognosis for diffuse large B-cell lymphoma (DLBCL), one of the most common types of non-Hodgkin lymphoma (NHL). Through gene expression profiles, this study intends to reveal potential subtypes among patients with DLBCL by evaluating their prognostic impact on immune cells. Methods Immune subtypes were developed based on CD8+ T cells and natural killer cells calculated from gene expression profiles. The comparison of prognoses and enriched pathways was made between immune subtypes. Following this validation step, samples from the independent data set were analyzed to determine the correlation between immune subtype and prognosis and immune checkpoint blockade (ICB) response. To provide a model to predict the DLBCL immune subtypes, machine learning methods were used. The virtual screening and molecular docking were adopted to identify small molecules to target the immune subtype biomarkers. Results A training data set containing 432 DLBCL samples from five data sets and a testing dataset containing 420 DLBCL samples from GSE10846 were used to develop and validate immune subtypes. There were two novel immune subtypes identified in this study: an inflamed subtype (IS) and a noninflamed subtype (NIS). When compared with NIS, IS was associated with higher levels of immune cells and a better prognosis for immunotherapy. Based on the random forest algorithm, a robust machine learning model has been established by 12 hub genes, and the area under the curve (AUC) value is 0.948. Three small molecules were selected to target NIS biomarkers, including VGF, RAD54L, and FKBP8. Conclusion This study assessed immune cells as prognostic factors in DLBCL, constructed an immune subtype that could be used to identify patients who would benefit from ICB, and constructed a model to predict the immune subtype.

MYC and BCL-2 protein co-expression and prognosis of patients with diffuse large B-cell lymphoma: a propensity score matching analysis

目的探究MYC/BCL-2蛋白双表达对弥漫大B细胞淋巴瘤（DLBCL）患者预后的影响，观察纳入DA-EPOCH-R（利妥昔单抗+依托泊苷+泼尼松+长春新碱+环磷酰胺+表阿霉素）、中枢神经系统预防治疗、移植等治疗因素后，双表达是否仍是DLBCL的独立预后不良因素。方法回顾性收集2015−2018年在北京协和医院血液科治疗且具有可用病理结果的223例初治DLBCL患者，75例MYC/BCL-2高表达的患者归为双表达组，从148例非双表达的患者中，应用倾向性评分（PSM），根据年龄、国际预后指数（IPI）评分、治疗选择等因素进行1∶1匹配，筛选出75例作为对照组，比较两组患者总生存（OS）及无进展生存（PFS）等方面的差异。结果PSM后双表达组和非双表达组的3年OS率分别为（69.8±5.5）％及（77.0±4.9）％（P＝0.225），3年PFS率分别为（60.7±5.8）％及（65.3±5.5）％（P＝0.390），差异均无统计学意义。R-CHOP方案（利妥昔单抗+环磷酰胺+阿霉素+长春新碱+泼尼松）治疗的亚组分析显示，双表达和非双表达患者的3年OS率分别为（61.3±7.5）％及（77.2±5.6）％（P＝0.027），3年PFS率分别为（52.1±7.5）％及（70.6 ± 6.0）％（P＝0.040），差异均具有统计学意义。多因素Cox回归分析显示年龄、Ann Arbor分期、细胞起源（COO）分型、是否进行中枢神经系统预防、是否进行移植是DLBCL患者预后的独立影响因素（P值均<0.05），而MYC/BCL-2蛋白双表达不是预后的影响因素。结论MYC/BCL-2蛋白双表达在R-CHOP方案治疗下与不良预后显著相关，但在DA-EPOCH-R、移植等治疗方案下，双表达对DLBCL的不良预后影响在一定程度上得到消除。

Prognostic significance of neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, platelet/neutrophil ratio, and mean platelet volume in patients diagnosed with Hodgkin and Non-Hodgkin Lymphoma

Aim: We aimed to show whether easily accessible NLR, PLR, PNR and MPV values can be used as prognostic markers in lymphoma subtypes and whether they can contribute to existing prognostic scoring systems. &#x0D; Material and Methods: The records of all lymphoma patients between 2005-2019 were reviewed retrospectively. NLR, PLR, PNR and MPV values at the time of diagnosis were compared with Progression-Free Survival (PFS) and Overall Survival (OS) durations. &#x0D; Results: PLR and NLR values in Marginal Zone Lymphoma (MZL) and PNR and MPV values in Diffuse Large B-cell Lymphoma (DLBCL) were found to be associated with prognosis and to have a direct effect on PFS and OS. Except for these parameters, we found that lactate dehydrogenase (LDH), MPV, age, stage and histological subtype had an effect on prognosis for all patients. &#x0D; Conclusion: It has been concluded that PLR and NLR can be used as prognostic factors in MZL, whereas PNR and MPV can be used as prognostic factors in DLBCL, and that these values can be used as easily accessible methods in disease prognosis scores.

Abstract PR14: Mutational landscape of diffuse large B cell lymphoma in patients with genome-defined African ancestry

Abstract Significant differences have been observed in the incidence, age of onset, and clinical outcomes of diffuse large B-cell lymphoma (DLBCL) by race in the United States. However, it remains unclear what factors underlie these differences and whether genomic differences contribute to these disparities. We examined differences in baseline clinical characteristics for black and white patients with DLBCL and the relationships between race and outcomes. To understand the influences of genetic ancestry on tumor genomic alterations, in a recent paper (Lee et al, Cancer. 2020), we estimated the genetic ancestry of 1,001 previously described patients with DLBCL (Reddy et al, Cell. 2017) using unsupervised model-based Admixture global ancestry analysis applied to exome sequencing data and examined the mutational profile of 150 DLBCL driver genes. Global ancestry prediction identified 619 patients with &amp;gt;90% European ancestry, 81 patients with &amp;gt;90% African ancestry, and 50 patients with &amp;gt;90% Asian ancestry. Compared to DLBCL patients with &amp;gt;90% European ancestry, patients with &amp;gt;90% African ancestry were younger at the time of diagnosis and more commonly presented with B symptoms, abnormally elevated serum lactate dehydrogenase, extranodal disease, and advanced stage disease. All except younger age are poor prognostic factors in DLBCL. Patients with &amp;gt;90% African ancestry more commonly had mutations in six DLBCL driver genes compared with patients with &amp;gt;90% European ancestry: ATM (21.0% vs 7.75%; P &amp;lt; .001), MGA (19.7% vs 5.33%; P &amp;lt; .001), SETD2 (17.3% vs 5.17%; P &amp;lt; .001), TET2 (12.3% vs 5.82%; P = .029), KMT2C/MLL3 (11.1% vs 4.36%; P = .013), and DNMT3A (11.1% vs 4.52%; P = .016). Patients with &amp;gt;90% African ancestry also demonstrated worse overall survival compared with patients with &amp;gt;90% European ancestry (median, 4.9 years vs 8.8 years; P = .04). We further analyzed previously identified germline genetic loci associated with DLBCL susceptibility among predominantly European populations to evaluate local chromosomal ancestry in the African ancestry group. Additional comparisons of DLBCL subtype among individuals of African compared with European ancestry are being performed using the LymphGen probabilistic classification tool for genetic subtypes of DLBCL with therapeutic implications (Wright et al. Cancer Cell. 2020). The distinct patterns of clinical characteristics, somatic mutations, genetic alterations, and subtype distributions highlight important differences in the landscape of DLBCL arising in different ancestry groups. This characterization among patients with African ancestry who are diagnosed with DLBCL provides a roadmap for future studies in other malignancies for constructing multilevel models that address race and ancestry and a pathway for drug development in areas where these genomic alterations are found to be associated with worse clinical outcomes. Citation Format: Michelle J. Lee, Jean L. Koff, Michelle A.T. Hildebrandt, Jeffrey M. Switchenko, C. I. Jhaney, R. A. Harkins, Sharvil P. Patel, Sandeep S. Dave, Christopher R. Flowers. Mutational landscape of diffuse large B cell lymphoma in patients with genome-defined African ancestry [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PR14.

Abstract 2035: Listen to the patients: Assessing the prognostic value of pre-treatment health-related quality of life in 1L DLBCL patients

Abstract Background: Identifying patients with high-risk of progression or death is important in developing novel treatment strategies in diffuse large B-cell lymphoma (DLBCL). The International Prognostic Index (IPI) is a commonly used score to classify the prognostic risk of previously untreated (1L) DLBCL patients. Although perceived as important in understanding the health status of patients, patient-reported health-related quality-of-life (HRQoL) measures have not been studied extensively as prognostic factors in DLBCL. In this study, we explored the prognostic value of pretreatment HRQoL in progression free survival (PFS) and overall survival (OS) in 1L DLBCL patients, using data from the phase III GOYA study (NCT01287741, Obinutuzumab-CHOP vs Rituximab-CHOP). Method: Four preselected pretreatment HRQoL subscale scores (lymphoma specific [LYMS], physical functioning [PF2], role functioning [RF2], and fatigue [FA]) were derived from two HRQoL questionnaires (EORTC-QLQ C30 and FACT-Lym) in the GOYA study. Each subscale was dichotomized to indicate low or high HRQoL based on their respective median scores (table). Sensitivity analyses were similarly evaluated. The prognostic value of each HRQoL subscale was evaluated using Cox proportional hazard models, adjusted for the five components of IPI. Table. Summary of prognostic value for the four pre-treatment HRQoL subscales Summary 3-year OS estimate2 (95% CI) Cox proportional hazard model Subscale(n1) Questionnaire Median (min-max) Low HRQoL High HRQoL OS HR3 (95% CI) PFS HR3(95% CI) Lymphoma specific(n = 1246) FACT-LYM 47 (7-60) 0.78 (0.74, 0.81) 0.85 (0.82, 0.87) 0.7 (0.51, 0.95) 0.81(0.63, 1.03) Physical functioning(n = 1254) EORTC-QLQ C30 87(0-100) 0.77 (0.74, 0.80) 0.86 (0.83, 0.89) 0.6 (0.43, 0.85) 0.72(0.56, 0.93) Role functioning(n = 1256) EORTC-QLQ C30 83(0-100) 0.78 (0.75, 0.81) 0.84 (0.81, 0.88) 0.72(0.52, 0.99) 0.84(0.65, 1.07) Fatigue(n = 1256) EORTC-QLQ C30 33(0-100) 0.74(0.70, 0.78) 0.84 (0.82, 0.87) 0.68 (0.5, 0.92) 0.94(0.73, 1.2) 1Only patients with valid respective pretreatment HRQoL scores were included in each analysis 2OS estimated using the Kaplan-Meier method 3HR = hazard ratio representing high HRQoL vs. low HRQoL, adjusted for the five components of IPI: age(≤60 vs &amp;gt;60), ECOG PS(0-1 vs 2-3), lactate dehydrogenase level (LDH)(≤1 normal vs &amp;gt;1 normal), Ann Arbor stage (Stage I or II vs III or IV disease), and extranodal sites(≤1 vs &amp;gt;1 extranodal site) Results: All four HRQoL subscales contributed independent prognostic value to patient outcome (table). Results show that high HRQoL is associated with better survival outcome (higher 3-year OS estimate and lower risk [HR]) compared with low HRQoL. Among the four subscales, PF2 had the highest estimated contribution to prognosis (OS: HR = 0.59, 95% CI: [0.42, 0.84], PFS: HR = 0.71, 95% CI [0.55, 0.93]). Conclusion: Our findings demonstrate the potential of patient-reported HRQoL measures in providing prognostic value in addition to IPI, which may contribute to improved risk stratification and inform treatment decisions for DLBCL patients. Citation Format: Huang Huang, Asim Datye, Ming Fan, Andrea Knapp, Rama Balakrishnan, Sandhya Balasubramanian, Julia Chae, Emma Roth, Tina Nielsen, Joseph N. Paulson, Peter Trask. Listen to the patients: Assessing the prognostic value of pre-treatment health-related quality of life in 1L DLBCL patients [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 2035.

Analysis of Micro-RNAs Associated to Treatment Failure in Diffuse Large B Cell Lymphoma

Introduction: Micro-RNAs (miRNAs) are 19-24 nucleotide non-coding RNAs that regulate gene expression through the inactivation of their messenger RNA. Previous studies have demonstrated the important role of some miRNAs in the development of cancer. Specifically, in diffuse large B cell lymphoma (DLBCL), miRNAs involved in lymphomagenesis were identified but understanding their biological function continues to be a challenge. Nevertheless, the pathogenesis effects of some miRNAs such as miR-125a, miR-17-92 cluster or mi-R-155 are well characterized. Some studies suggest that miRNAs also possess a prognostic potential role in DLBCL. For this reason, our objective was to analyze the different miRNAs involved in the chemo-sensitivity or resistance to the first line treatment, their correlation with standard prognostic factors at diagnosis and the role of these miRNAs in survival in patients with DLBCL. Material and methods: Patients homogeneously treated with R-CHOP from 1999-2013 were reviewed from 3 Spanish centers. They were retrospectively obtained from Pathology Department registry to avoid selection bias. We included those patients with valid genomic material in formalin-fixed-paraffin-embedded tissue and with available clinical data. Samples were processed using the miRNA 4 Affymetrix microarrays kit in a discovery group that included 2 cohorts (patients with durable complete remission (CR) versus refractory or early relapsing patients). Those miRNAs with differential expression were validated in the whole series with quantitative RT-PCR. We also analyzed the role of these miRNAs as predictors of event-free survival (EFS) and overall survival (OS) and their relationship with standard prognostic factors in DLBCL. Results: We identified 156 patients homogeneously treated with R-CHOP. Finally, 96 samples were obtained with valid material for RNA extraction. To identify those miRNAs with prognostic implication, a discovery cohort of 12 patients was used in which all the cases had poor prognosis with high tumor load and advance disease (III-IV stage and unfavorable R-IPI). On this basis of poor prognosis, 2 groups were defined totally opposed from the point of view of the treatment response and evolution: chemo-resistance group (n=6) including refractory or relapsed (RR) patients (first 12 months) and chemo-sensitive group (n=6) including patients with at least 3 years of CR. A hierarchical clustering was performed in which 26 miRNAs differentially expressed were identified. A screening of miRNAs was carried out based on the fold-change and pathways involved and finally we obtained 10 miRNAs differentially expressed in RR group. The validation of these miRNAs was performed with quantitative RT-PCR in the whole series which finally included 68 samples with valid material. A univariate survival analysis including clinical prognostic factors and the selected 10 miRNAs was performed. We confirmed that 7 of them (miR-20b-5p, miR-1244, miR-6840-3p, miR-1231, miR-193b-5p, miR-6860-5p y miR-199a-5p) significantly influenced EFS and 6 of them (miR-1244, miR-1231, miR-193b-5p, miR-885-3p, miR-182-5p y miR-199a-5p) on OS. From these 10 miRNAs, only 3 had a significant prognosis role not only for EFS but also for OS and progression-free survival (PFS): miR-1244, miR-193b-5p and miR-1231. The overexpression of miR-1244 and miR-193-5p were associated with advance stage and worse clinical prognosis factors (p&lt;0.05). A multivariate analysis was performed including clinical and biological variables and we obtained that the overexpression of miR-1231, high R-IPI and a reduction of relative dose intensity (RDI) &gt;15% were independently associated with worse SG and EFS (Figure 1). In previously reported studies, these 3 miRNAs have been related with proliferative events such as the overexpression of myc or anti-apoptosis. Also, the miR-1231 may be related with new lymphomagenesis pathways associated to viral infections. Conclusions: Through a discovery group focused on progression/refractoriness, a group of new miRNAs differentially expressed on chemo-resistant patients with DLBCL was identified. The overexpression of miR-1244 and miR-193-5p was associated with more extensive disease and worse clinical prognostic factors. The high R-IPI, reduction of &gt;15% RDI and the overexpression of miR-1231 were independently associated with worse EFS and OS. Disclosures Sánchez-González: Amgen: Consultancy, Speakers Bureau; Gilead: Speakers Bureau; Navartis: Consultancy, Speakers Bureau; Shire: Speakers Bureau; Takeda: Consultancy, Speakers Bureau. Salar:Roche: Research Funding, Speakers Bureau; Janssen Pharmaceuticals: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy.

Serum microRNA Prognostic Model and Underlying Immune Alterations in Diffuse Large B Cell Lymphoma

Serum microRNA prognostic model and underlying immune alterations in diffuse large B cell lymphoma Abstract Background: MicroRNAs (miRs) have been investigated as prognostic biomarkers and therapeutic targets in diffuse large B-cell lymphoma (DLBCL). Translating these findings into clinical approaches should be validated by independent patient cohorts and a better understanding of underlying biology mechanism remains great interests. Methods: MiRNA microarray was performed on serum samples of 20 DLBCL patients at diagnosis, remission and at relapse. Subsequent real-time PCR validation of 504 newly diagnosed DLBCL patients was used to generate a serum prognostic model in predicting clinical outcomes. The mechanism of action of miR signature on tumor progression was further analyzed by whole exome sequencing and RNA sequencing. Results: Four serum miRs (miR-21, miR-155, miR-130b and miR-28) were identified to predict relapse in a training cohort of 225 DLBCL patients and validated in a validation cohort of 279 DLBCL patients. Multivariate Cox regression models indicated that when the International Prognostic Index was controlled, this serum miR prognostic model was an independent prognostic factor in DLBCL. Moreover, mutations of transcription factors (TFs) were significantly correlated with these four miRs. Twenty lymphoma-associated TFs regulated at least one miR by transmiR v2.0 database and different genetic mutation burden was present between low-index and high-index of the model. Furthermore, RNA sequencing data manifested that the four-miR signature correlated with immune status of the DLBCL patients. Conclusions: An easy-to-use miR prognostic model was utilized to predict disease relapse and prognosis of DLBCL patients. The tumor-specific mutation burden and immune dysregulation potentially contribute to tumor progression in DLBCL. Key words: MicroRNAs, Diffuse Large B-cell Lymphoma, Prognosis, Signaling pathways. Disclosures No relevant conflicts of interest to declare.

PF323 DOUBLE‐HIT DIFFUSE LARGE B‐CELL LYMPHOMA IN TAIWAN IS PREDOMINANTLY BCL6‐REARRANGED AND OVEREXPRESSION OF MYC AND BCL6 IS NOT A GOOD SURROGATE FOR SCREENING

Background:Diffuse large B‐cell lymphoma (DLBCL) is the most common subtype of the non‐Hodgkin's lymphoma all over the world and it is extremely heterogeneous both clinically and pathologically. Concurrent MYC and BCL2/BCL6 translocations, the so‐called double hits (DH) has been identified as an important reverse prognostic factor in DLBCL. Chang and his colleagues have published a manuscript to describe the immunophenotypic and genetic characteristics of DLBCL in Taiwan in 2016. In their study, BCL6, rather than BCL2, rearrangement seemed predominant in DH DLBCL although only 3 patients were identified. BCL6‐rearranged DH DLBCL has been less discussed because it accounts for only 20–25% of all cases in the Western countries. Therefore the importance of BCL6 rearrangement in DH DLBCL should be explored in Taiwan.Aims:We would like to confirm the predominance of BCL6 rearrangement in DH DLBCL in Taiwan. In addition, we would like to figure out the phenotypes and the status of Myc and BCL6 protein expression in BCL6‐rearranged DH DLBCL.Methods:We retrieved 154 patients with pathological‐confirmed, newly‐diagnosed DLBCL patients from Shuang‐Ho Hospital, Wan‐Fang Hospital and Taipei Meidcal University Hospital. Fluorescence insitu hybridization (FISH) to detect MYC rearrangement was performed in all patients. BCL2 and BCL6 rearrangements were checked by FISH when positive MYC rearrangement was confirmed. Immunohistochemical (IHC) stains for Myc, BCL2, BCL6, CD10 and MUM1 were done in all patients.Results:Among the 154 patients, 25 of them had MYC translocation (16.2%). Of the 25 MYC‐rearranged patients, concurrent BCL2 or BCL6 translocation was detected in 12 patients. Two‐thirds of them (8 patients) had simultaneous MYC and BCL6 translocations while the other 3 were MYC‐ and BCL2‐rearranged (Figure 1). We had one patient with concurrent MYC, BCL2 and BCL6 translocations, the so‐called triple hits (TH). Taken together, 75% of DH (including TH) DLBCL patients had BCL6 rearrangement and therefore we confirmed the predominance of BCL6 rearrangement in Taiwan. Among DH (including TH) DLBCL patients with BCL6 rearrangement, only 3 out of 9 (33.3%) expressed Myc and BCL6 proteins simultaneously in the IHC stains (Table 1) and consequently, simultaneous overexpression of Myc and BCL6 proteins was not a good surrogate to screen BCL6‐rearranged DH DLBCL. Five patients (55.6%) were non‐germinal center B‐cell (non‐GCB) phenotype in BCL6‐rearranged DH (including TH) patients (Figure 2), indicating the screening of DH with BCL6 rearrangement should include the non‐GCB phenotype of DLBCL.Summary/Conclusion:1. The majority (75%) of DH (including TH) DLBCL in Taiwan had BCL6 rearrangement and it was quite different from data of the Western countries.image2. The concurrent overexpression of Myc and BCL6 proteins in the IHC stains was not a good surrogate to screen BCL6‐rearranged DH DLBCL.3. More than half (55.6%) of BCL6‐rearranged DH (including TH) DLBCL were non‐GCB phenotype, indicating the screening of DH with BCL6 rearrangement should include the non‐GCB phenotype of DLBCL in Taiwan.4. The screening of BCL6‐rearranged DH DLBCL was mandatory in Taiwan.

The anaphase-promoting complex/cyclosome: a new promising target in diffuse large B-cell lymphoma and mantle cell lymphoma

BackgroundThe aggressive B-cell non-Hodgkin lymphomas diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) are characterised by a high proliferation rate. The anaphase-promoting complex/cyclosome (APC/C) and its co-activators Cdc20 and Cdh1 represent an important checkpoint in mitosis. Here, the role of the APC/C and its co-activators is examined in DLBCL and MCL.MethodsThe expression and prognostic value of Cdc20 and Cdh1 was investigated using GEP data and immunohistochemistry. Moreover, the therapeutic potential of APC/C targeting was evaluated using the small-molecule inhibitor proTAME and the underlying mechanisms of action were investigated by western blot.ResultsWe demonstrated that Cdc20 is highly expressed in DLBCL and aggressive MCL, correlating with a poor prognosis in DLBCL. ProTAME induced a prolonged metaphase, resulting in accumulation of the APC/C-Cdc20 substrate cyclin B1, inactivation/degradation of Bcl-2 and Bcl-xL and caspase-dependent apoptosis. In addition, proTAME strongly enhanced the anti-lymphoma effect of the clinically relevant agents doxorubicin and venetoclax.ConclusionWe identified for the first time APC/C as a new, promising target in DLBCL and MCL. Moreover, we provide evidence that Cdc20 might be a novel, independent prognostic factor in DLBCL and MCL.

A New Stromal Signature Applicable to Formalin-Fixed Paraffin-Embedded Tissues Identifies Patients at Risk in Prospective Clinical Trials of the German High-Grade Non-Hodgkin Lymphoma Study Group

Diffuse large B-cell-lymphoma (DLBCL) is a heterogeneous disease in its sites of origin, genetic alterations, and clinical behavior. Gene expression profiling (GEP) has led to the identification of two molecular subtypes, GCB-like and ABC-like DLBCL, that follow different molecular circuits and hence, likely represent different diseases. Next to the ABC-like GEP, the rearrangement and/or expression of MYC and TP53 mutations in tumors characterize patient subsets with inferior prognosis. However, the clinical impact of cell of origin (COO) subtyping and the identification of prognostic biomarkers differ between studies. In many clinical trials, patients identified “at risk” experience cure and long-time survival. Important factors modulating the impact of tumor cell-specific factors may be conferred by the host microenvironment, and stromal signatures have been shown to be correlated to survival in DLBCL. The robust analysis of stromal signatures is hampered by the lack of assays applicable to routinely used formalin-fixed paraffin-embedded (FFPE) materials. We have constructed a molecular signature applicable to FFPE, interrogating the quantitative and qualitative composition of the microenvironment in DLBCL. The signature was trained using an algorithm that extracts prognostic information out of the ratios of pairs of genes. The genes that drive prognosis are expressed in T-cells and macrophages and have function in the communication between both cell types. The model was validated using the NanoString assay in a cohort of 466 DLBCL patients enrolled in 7 prospective clinical trials (MInT, MegaCHOEP phase III and observation, RICOVER-60, RICOVER-noRTh, DENSER, SMARTER) of the German High grade non-Hodgkin's lymphoma study group (DSHNHL). Grouping of the patients into quartiles according to the expression of the continuous stromal signature score (ranging from -1.880to 4.441) resulted in three quartiles (Q1-3) with comparable clinical behavior (stromal signature low). Patients from quartile 4 (Q4), however, characterized by high expression of the signature (stromal signature high), showed a clearly inferior outcome in EFS, PFS and OS (Figure 1 a-c). This result could be independently reproduced in the seven clinical trials named above, thus clearly depicting the robustness of the signature. Multivariate analysis revealed that high expression of the stromal signature is a prognostic risk factor independent of the IPI factors in EFS (HR 1.7, 95 % CI 1.2-2.4, p-value =0.001), PFS (HR 1.8, 95 % CI 1.2-2.5, p-value =0.001) and OS (HR1.8, 95 % CI 1.3-2.7, p-value =0.001). Combining stromal signature count with IPI-score led to the identification of a high-risk cohort (Fig. 1 d-f). Of importance, additional multivariate analyses adjusted for the IPI factors performed within selected trials showed that the stromal signature provides prognostic information independent of the COO status, MYC and dual MYC/BCL2 rearrangements, TP53 mutations and the MYC/BCL2 double expresser status.In summary, our data from prospectively randomized trials of the DSHNHL underline the importance of the microenvironment in the prognostic stratification of DLBCL patients and suggest that the composition and quality of the tumor stroma is an independent risk factor in DLBCL. Analysis of stromal features, therefore, may provide a rationale for targeted treatment approaches, e.g. with immunomodulatory substances (IMIDs), in patients at risk. [Display omitted] DisclosuresKlapper:Regeneron: Honoraria, Research Funding; HTG Molecular Diagnostics, Inc.: Research Funding; F.Hoffman-La Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding. Richter:HTG Molecular Diagnostics, Inc.: Research Funding. Poeschel:Roche: Other: Travel grants; Amgen: Other: Travel grants. Held:BMS: Consultancy, Other: Travel grants, Research Funding; Spectrum: Research Funding; Roche: Consultancy, Other: Travel grants, Research Funding; Amgen: Research Funding; MSD: Consultancy.

Tumor fragmentation estimated by volume surface ratio of tumors measured on 18F-FDG PET/CT is an independent prognostic factor of diffuse large B-cell lymphoma.

Our aim was to study the prognostic value of two new 18F-FDG PET biomarkers in diffuse large B-cell lymphoma (DLBCL). We examined the total tumor surface (TTS), describing the tumor-host interface, and the tumor volume surface ratio (TVSR), corresponding to the ratio between the total metabolic tumor volume (TMTV) and TTS, describing the tumor fragmentation. We retrospectively included 215 patients with DLBCL. Patients underwent initial 18F-FDG PET/CT before R-CHOP (73%) or intensified R-CHOP (R-ACVBP) regimens (27%). The TMTV was measured using a fixed threshold value of 41% of SUVmax. To calculate TTS and TVSR, the surface was measured using an in-house software based on the marching cube algorithm. Spearman's rank correlation coefficient (ρ) was computed between TMTV, TTS, and TVSR, and ROC analysis was performed. Survival functions at 5years were studied using a Kaplan-Meier method and uni/multivariate Cox analysis. TVSR was poorly correlated with TMTV (ρ = 0.5) and TTS (ρ = 0.26), while TTS was highly correlated with TMTV (ρ = 0.94) and was, therefore, excluded from the analysis. TMTV had the highest area under the ROC curve (0.711) and the best sensitivity (0.797), while TVSR had the best specificity (0.745). The optimal cut-off values to predict 5-year OS were 222cm3 for TMTV and 6.0mm for TVSR. Patients with high TMTV and TVSR had significantly worse prognosis in Kaplan-Meier and Cox univariate analysis. In a multivariate Cox analysis combining the International Prognostic Index (IPI), the type of chemotherapy, TMTV, and TVSR, all parameters were independent and significant prognostic factors (HR [95%CI]: IPI 1.4 [1.1-1.8], type of chemotherapy 4.5 [2.0-10.5], TMTV 2.8 [1.4-5.5], TVSR 2.1 [1.3-3.4]). A synergistic effect between TMTV and TVSR was observed in a Kaplan-Meier analysis combining the two parameters. TVSR measured on the initial 18F-FDG PET is an independent prognostic factor in DLBCL and has an additional prognostic value when combined with TMTV, IPI score and chemotherapy.