Evaluating cell-of-origin subtype methods for predicting diffuse large B-cell lymphoma survival: a meta-analysis of gene expression profiling and immunohistochemistry algorithms

Still Far to Go With Characterisation of Molecular and Genetic Features of Diffuse Large B-Cell Lymphoma in People Living With HIV: A Scoping Review

Diffuse large B-cell lymphoma (DLBCL) accounts for half of non-Hodgkin lymphoma cases in people living with human immunodeficiency syndrome (PLWH). The interplay of viremia, immune dysregulation and co-infection with oncogenic viruses play a role in pathogenesis of DLBCL in PLWH (HIV-DLBCL). This scoping review aimed to describe the molecular landscape of HIV-DLBCL, investigate the impact of biomarker on clinical outcomes and describe technologies used to characterise HIV-DLBCL. Thirty-two papers published between 2001 and 2023 were included in this review. Samples of HIV-DLBCL were relatively small (16-110). Cohort effects influenced frequencies of molecular characteristics hence their impact on survival was not clear. Molecular features were distinct from HIV-unrelated DLBCL. The most frequently assessed characteristic was cell of origin (81.3% of studies). Somatic mutations were the least researched (6.3% of studies). Overall, biomarker identification in HIV-DLBCL requires broader richer data from larger or pooled samples using more powerful techniques such as next-generation sequencing.

Predictive Value of Corrected 18 F-FDG PET/CT Baseline Parameters for Primary DLBCL Prognosis: A Single-center Study

Objective  The purpose of this study was to evaluate the prognostic significance of corrected baseline metabolic parameters in fluorodeoxyglucose positron emission tomography imaging ( 18 F-FDG PET/CT) for 3-year progression-free survival (PFS) in patients with primary diffuse large B cell lymphoma (DLBCL). Patients and Methods  Retrospective clinical and pathological data were collected for 199 patients of DLBCL diagnosed between January 2018 and January 2021. All patients underwent 18 F-FDG PET/CT scans without any form of treatment. The corrected maximum standardized uptake value (corSUVmax), corrected mean standardized uptake value (corSUVmean), corrected whole-body tumor metabolic volume sum (corMTVsum), and corrected total lesion glycolysis of whole body (corTLGtotal) were corrected using the SUVmean in a 1-cm diameter mediastinal blood pool (MBP) from the descending thoracic aorta of patients. Kaplan-Meier survival curves and Cox regression were used to examine the predictive significance of corrected baseline metabolic parameters on 3-year PFS of patients. The incremental values of corrected baseline metabolic parameters were evaluated by using Harrell's C-indices, receiver operating characteristic, and Decision Curve Analysis. Results  The multivariate analysis revealed that only the National Comprehensive Cancer Network (NCCN)-International Prognostic Index (IPI) and corMTVsum had an effect on 3-year PFS of patients ( p  < 0.05, respectively). The Kaplan-Meier survival analysis demonstrated significant differences in PFS between the risk groups classified by corSUVsum, corMTVsum, and corTLGtotal (log-rank test, p  < 0.05). The predictive model composed of corMTVsum and corTLGtotal surpasses the predictive performance of the model incorporating MTVsum and TLGtotal. The optimal performance was observed when corMTVsum was combined with NCCN-IPI, resulting in a Harrell's C index of 0.785 and area under the curve values of 0.863, 0.891, and 0.947 for the 1-, 2-, and 3-year PFS rates, respectively. Conclusion  The corMTVsum offers significant prognostic value for patients with DLBCL. Furthermore, the combination of corMTVsum with the NCCN-IPI can provide an accurate prediction of the prognosis.

Distribution and clinical impact of molecular subtypes with dark zone signature of DLBCL in a Japanese real-world study

The distribution and clinical impact of cell-of-origin (COO) subtypes of diffuse large B-cell lymphoma (DLBCL) outside Western countries remain unknown. Recent literature also suggests that there is an additional COO subtype associated with the germinal center dark zone (DZ) that warrants wider validation to generalize clinical relevance. Here, we assembled a cohort of Japanese patients with untreated DLBCL and determined the refined COO subtypes, which include the DZ signature (DZsig), using the NanoString DLBCL90 assay. To compare the distribution and clinical characteristics of the molecular subtypes, we used a data set from the cohort of British Columbia Cancer (BCC) (n = 804). Through the 1050 patient samples on which DLBCL90 assay was successfully performed in our cohort, 35%, 45%, and 6% of patients were identified to have germinal center B-cell-like (GCB) DLBCL, activated B-cell-like (ABC) DLBCL, and DZsig-positive (DZsigpos) DLBCL, respectively, with the highest prevalence of ABC-DLBCL, differing significantly from the BCC result (P < .001). GCB-DLBCL, ABC-DLBCL, and DZsigpos-DLBCL were associated with 2-year overall survival rates of 88%, 75%, and 66%, respectively (P < .0001), with patients with DZsigpos-DLBCL having the poorest prognosis. In contrast, GCB-DLBCL without DZsig showed excellent outcomes after rituximab-containing immunochemotherapy. DZsigpos-DLBCL was associated with the significant enrichment of tumors with CD10 expression, concurrent MYC/BCL2 expression, and depletion of microenvironmental components (all, P < .05). These results provide evidence of the distinct distribution of clinically relevant molecular subtypes in Japanese DLBCL and that refined COO, as measured by the DLBCL90 assay, is a robust prognostic biomarker that is consistent across geographical areas.

Salinomycin sodium exerts anti diffuse large B-cell lymphoma activity through inhibition of LRP6-mediated Wnt/β-catenin and mTORC1 signaling

Low-density lipoprotein receptor-related protein-6 (LRP6) is overexpressed in various cancers. The small molecule salinomycin sodium inhibits LRP6. We observed a higher proportion of subjects with non-germinal center B (non-GCB) subtypes having high LRP6 expression than those with GCB subtypes by immunohistochemistry. The PCR and Western blot assays demonstrated increased LRP6 expression in non-GCB subtype cells. In addition, CCK-8 assays and transwell cell migration assays revealed that salinomycin sodium exhibited dose- and time-dependent inhibition of proliferation and migration in non-GCB subtype cells. Furthermore, Western blot assays showed that salinomycin sodium decreased the expression of Bcl2, while increasing the expression of Bax. Additionally, salinomycin sodium suppressed LRP6 expression, blocked LRP6 phosphorylation, and inhibited the Wnt/β-catenin and mTORC1 signaling pathways. Our results suggest that LRP6 is highly expressed in non-GCB subtype. Furthermore, salinomycin sodium inhibited LRP6 expression and the Wnt/β-catenin and mTORC1 signaling in non-GCB subtype cells, and displayed potent anticancer activity.

Genomic profiling for clinical decision making in lymphoid neoplasms

With the introduction of large-scale molecular profiling methods and high-throughput sequencing technologies, the genomic features of most lymphoid neoplasms have been characterized at an unprecedented scale. Although the principles for the classification and diagnosis of these disorders, founded on a multidimensional definition of disease entities, have been consolidated over the past 25 years, novel genomic data have markedly enhanced our understanding of lymphomagenesis and enriched the description of disease entities at the molecular level. Yet, the current diagnosis of lymphoid tumors is largely based on morphological assessment and immunophenotyping, with only few entities being defined by genomic criteria. This paper, which accompanies the International Consensus Classification of mature lymphoid neoplasms, will address how established assays and newly developed technologies for molecular testing already complement clinical diagnoses and provide a novel lens on disease classification. More specifically, their contributions to diagnosis refinement, risk stratification, and therapy prediction will be considered for the main categories of lymphoid neoplasms. The potential of whole-genome sequencing, circulating tumor DNA analyses, single-cell analyses, and epigenetic profiling will be discussed because these will likely become important future tools for implementing precision medicine approaches in clinical decision making for patients with lymphoid malignancies.

Extracellular Vesicles in Diffuse Large B Cell Lymphoma: Characterization and Diagnostic Potential

Diffuse large B cell lymphoma (DLBCL) is an aggressive B cell lymphoma characterized by a heterogeneous behavior and in need of more accurate biological characterization monitoring and prognostic tools. Extracellular vesicles are secreted by all cell types and are currently established to some extent as representatives of the cell of origin. The present study characterized and evaluated the diagnostic and prognostic potential of plasma extracellular vesicles (EVs) proteome in DLBCL by using state-of-the-art mass spectrometry. The EV proteome is strongly affected by DLBCL status, with multiple proteins uniquely identified in the plasma of DLBCL. A proof-of-concept classifier resulted in highly accurate classification with a sensitivity and specificity of 1 when tested on the holdout test data set. On the other hand, no proteins were identified to correlate with non-germinal center B-cell like (non-GCB) or GCB subtypes to a significant degree after correction for multiple testing. However, functional analysis suggested that antigen binding is regulated when comparing non-GCB and GCB. Survival analysis based on protein quantitative values and clinical parameters identified multiple EV proteins as significantly correlated to survival. In conclusion, the plasma extracellular vesicle proteome identifies DLBCL cancer patients from healthy donors and contains potential EV protein markers for prediction of survival.

Diagnostic Performance of PD-L1 versus PD-1 Expression in Circulating CD20 Cells in Diffuse Large B-Cell Lymphoma

This study aimed to investigate PD-L1 and PD-1 expression in circulating CD20+ cells in diffuse larger B-cell lymphoma (DLBCL) and to evaluate the predictive and diagnostic performance of PD-L1 versus PD-1 expression in circulating CD20+ cells in DLBCL. Percentages of CD20+, PD-L1+CD20+, and PD-1+CD20+ cells were measured by flow cytometry in 40 DLBCL blood samples and 19 healthy controls. The DLBCL patient group was subdivided into 20 newly diagnosed patients with no treatment yet and 20 patients that had finished six cycles of CHOP therapy. Percentages of PD-L1+CD20+ and PD-1+CD20+ cells were highly significantly increased in pre-therapy patients in comparison to healthy volunteers (p < 0.001). Meanwhile, a significant decrease in percentages of PD-L1+CD20+ and PD-1+CD20+ was observed in post-CHOP therapy patients in comparison to pre-therapy patients (p < 0.001). PD-L1+CD20+ cells were significantly decreased in post-therapy patients when compared to normal controls (p < 0.001), while not for PD-1+CD20+ cells. A strong significant positive correlation between percentages of PD-L1+CD20+ and PD-1+CD20+ was detected in DLBCL patients (p < 0.001). In the pre-therapy group, high PD-L1+CD20+ and PD-1+CD20+ percentages were correlated with serum LDH levels (p = 0.021, p < 0.001). High percentages of PD-1+CD20+ were found in DLBCL patients with splenomegaly (p = 0.027). The results revealed that patients with advanced tumor stages, poor ECOG performance, and non-GCB DLBCL type had increased percentages of PD-L1+CD20+ and PD-1+CD20+ cells. Moreover, PD-L1+CD20+ % and PD-1+CD20+ % were significantly increased in DLBCL patients with bone marrow involvement or B symptoms. The superiority of PD-L1+CD20+ over PD-1+CD20+ was more profound in DLBCL prediction [AUC: 1.0] and in discriminating newly diagnosed patients [AUC: 1.0]. The findings suggest that increased PD-L1/PD-1 expression in peripheral CD20 cells may serve as a companion diagnostic marker for DLBCL. Moreover, percentages of PD-L1+CD20+ cells have better diagnostic performance with higher sensitivity and specificity than PD-1+CD20+ %.

A Germinal Center-Associated Microenvironmental Signature Reflects Malignant Phenotype and Outcome of DLBCL

The DLBCL microenvironment signature scoring system was established using nCounter-based profiling of GC-related microenvironmental genes.

DMS scores stratified DLBCL patients with different prognosis independently of existing prognostic models.

Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell malignancy, with varying prognosis after the gold standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Several prognostic models have been established by focusing primarily on characteristics of lymphoma cells themselves, including cell-of-origin (COO), genomic alterations, and gene/protein expressions. However, the prognostic impact of the lymphoma microenvironment and its association with characteristics of lymphoma cells are not fully understood. Using the nCounter-based gene expression profiling of untreated DLBCL tissues, we assess the clinical impact of lymphoma microenvironment on the clinical outcomes and pathophysiological, molecular signatures in DLBCL. The presence of normal germinal center (GC)-microenvironmental cells, including follicular T cells, macrophage/dendritic cells, and stromal cells in lymphoma tissue indicates a positive therapeutic response. Our prognostic model, based on quantitation of transcripts from distinct GC-microenvironmental cell markers, clearly identified patients with graded prognosis independently of existing prognostic models. We observed increased incidences of genomic alterations and aberrant gene expression associated with poor prognosis in DLBCL tissues lacking GC-microenvironmental cells relative to those containing these cells. These data suggest that the loss of GC-associated microenvironmental signature dictates clinical outcomes of DLBCL patients reflecting the accumulation of “unfavorable” molecular signatures.

Diffuse large B-cell lymphoma: A consensus practice statement from the Australasian Lymphoma Alliance

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype, accounting for 30-40% of lymphoma diagnoses. Though aggressive, cure is achievable in approximately 60% of cases with primary chemo-immunotherapy, and in a further substantial minority by salvage therapy and autologous stem cell transplantation. Despite promising activity in early phase clinical trials, no intensified or novel treatment regimen has improved outcomes over R-CHOP21 in randomised studies. However, there remain several areas of controversy including the most appropriate prognostic markers, CNS prophylaxis and the optimal treatment for patients with high-risk disease. This position statement presents an evidence-based synthesis of the literature for application in Australasian practice. This article is protected by copyright. All rights reserved.

Molecular profiling in diffuse large B-cell lymphoma: why so many types of subtypes?

The term diffuse large B-cell lymphoma (DLBCL) includes a heterogeneous collection of biologically distinct tumours. This heterogeneity currently presents a barrier to the successful deployment of novel, biologically targeted therapies. Molecular profiling studies have recently proposed new molecular classification systems. These have the potential to resolve the biological heterogeneity of DLBCL into manageable subgroups of tumours that rely on shared oncogenic programmes. In many cases these biological programmes straddle the boundaries of our existing systems for classifying B-cell lymphomas. Here we review the findings from these major molecular profiling studies with a specific focus on those that propose new genetic subgroups of DLBCL. We highlight the areas of consensus and discordance between these studies and discuss the implications for current clinical practice and for clinical trials. Finally, we address the outstanding challenges and solutions to the introduction of genomic subtyping and precision medicine in DLBCL.

Why R-CHOP + X is not enough: lessons learned and next steps in the mission to improve frontline therapy for diffuse large B-cell lymphoma

Two-thirds of newly diagnosed cases of diffuse large B-cell lymphoma (DLBCL) are cured with R-CHOP, an immunochemotherapy regimen that has been the standard of care for almost two decades. Ongoing molecular characterization of DLBCL has revealed a heterogeneous disease comprised of multiple subtypes based on putative cell of origin or somatic mutations with unique oncogenic signaling pathways. The door has been opened to the use of novel agents that target the specific molecular vulnerabilities of DLBCL, but despite this, multiple randomized studies have not identified a suitable drug 'X' to combine with R-CHOP. This report will review recent attempts to add individual novel agents to R-CHOP in the mission to improve frontline treatment for DLBCL and discuss promising ongoing studies. It will offer potential strategies to explore when designing future clinical trials, including exploiting synergy between multiple novel agents.

Prognostic molecular biomarkers in diffuse large B-cell lymphoma in the rituximab era and their therapeutic implications

Diffuse large B-cell lymphoma (DLBCL) represents a group of tumors characterized by substantial heterogeneity in terms of their pathological and biological features, a causal factor of their varied clinical outcome. This variation has persisted despite the implementation of rituximab in treatment regimens over the last 20 years. In this context, prognostic biomarkers are of great importance in order to identify high-risk patients that might benefit from treatment intensification or the introduction of novel therapeutic agents. Herein, we review current knowledge on specific immunohistochemical or genetic biomarkers that might be useful in clinical practice. Gene-expression profiling is a tool of special consideration in this effort, as it has enriched our understanding of DLBCL biology and has allowed for the classification of DLBCL by cell-of-origin as well as by more elaborate molecular signatures based on distinct gene-expression profiles. These subgroups might outperform individual biomarkers in terms of prognostication; however, their use in clinical practice is still limited. Moreover, the underappreciated role of the tumor microenvironment in DLBCL prognosis is discussed in terms of prognostic gene-expression signatures, as well as in terms of individual biomarkers of prognostic significance. Finally, the efficacy of novel therapeutic agents for the treatment of DLBCL patients are discussed and an evidence-based therapeutic approach by specific genetic subgroup is suggested.

Role of Cell-Origin Profiling Using Immunohistochemistry to Predict the Survival of Patients with Diffuse Large B-Cell Lymphoma in Indonesia

Background

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in Asia and Indonesia. DLBCL could be further classified according to cell of origin as the germinal center B-cell (GCB) subtype or the non-germinal center B-cell (non-GCB) subtypes; of these, the non-GCB subtype usually has poorer prognosis. The purpose of this study is to determine the relationship between the cell-origin subtype and 3-year overall survival of patients with DLBCL at Kariadi General Hospital Semarang.

Methods

This research represents an observational analytical study of 36 patients with DLBCL who visited Kariadi General Hospital between January and August 2017. Data on age of diagnosis, tumor location, disease stage, and 3-year overall survival were collected. DLBCL subtype was determined via immunohistochemical examination of CD10, BCL6, and MUM1 protein expression. Data analyses, including the chi squared test and Kaplan-Meier curves, were conducted.

Results

The study population included 18 patients with GCB-subtype DLBCL and 18 patients with non-GCB-subtype DLBCL. No significant difference (P = 0.171) between disease stage and cell-origin subtype was noted between groups. Patients with the non-GCB subtype had a 3-year overall survival that was significantly worse than that of patients with the GCB subtype (P = 0.026). Moreover, the 3-year survival rate of patients with the non-GCB subtype of the disease was 38.9% while that of patients with the GCB subtype was 77.8%. Patients with advanced stages of DLBCL also had a 3-year overall survival that was significantly worse than those of patients with early stages of the disease (P < 0.001), with the 3-year survival rate of patients with advanced stage was 14.3%.

Conclusion

Patients with non-GCB-subtype DLBCL or advanced stages of the disease have a lower 3-year overall survival rate and poorer prognosis compared with those with other subtypes or earlier stages of the disease.

Clinical, inflammatory and immunohistochemical features in a cohort of Peruvian patients with diffuse large B-cell lymphoma

Data on response and survival outcomes of Latin American patients with diffuse Large B- cell lymphoma (DLBCL) are limited. We describe the clinical, inflammatory and immunohistochemical features of a cohort of DLBCL Peruvian patients treated with chemoimmunotherapy between 2010 and 2015. Logistic models were fitted for complete response (CR), and Cox proportional-hazard regression for progression-free survival (PFS) and overall survival (OS). Seventy-three patients were included in this analysis, 41 % had high/high-intermediate IPI and 48 % had high/high-intermediate NCCN-IPI scores, 41 % had non-germinal center (NGC) profile and 36 % were double expressors. CR was attained in 63 % of patients, median PFS was 53 months and median OS was 80 months. Both IPI and NCCN-IPI scores were statistically associated with PFS and OS. Neutrophil/lymphocyte ratio (NLR) ≥4 was associated with lower odds of CR (OR 0.19, p = 0.007), worse PFS (HR 2.67, p = 0.02) and worse OS (HR 2.77, p = 0.02). NLR ≥ 4 remained significant after adjusting for the IPI score and had a trend towards significance when adjusted for the NCCN-IPI score. Albumin <3.5 g/dl was associated with worse OS when adjusted for the NCCN-IPI score (HR 2.96, p = 0.04). NGC profile and double expressors were not prognostic. Our study identified NLR ≥ 4 and albumin <3.5 g/dl as potential adverse factors in DLBCL patients and could add to the prognostic value of the IPI or the NCCN-IPI scores.

Genome-wide Screens Identify Lineage- and Tumor-Specific Genes Modulating MHC-I- and MHC-II-Restricted Immunosurveillance of Human Lymphomas

Tumors frequently subvert major histocompatibility complex class I (MHC-I) peptide presentation to evade CD8+ T cell immunosurveillance, though how this is accomplished is not always well defined. To identify the global regulatory networks controlling antigen presentation, we employed genome-wide screening in human diffuse large B cell lymphomas (DLBCLs). This approach revealed dozens of genes that positively and negatively modulate MHC-I cell surface expression. Validated genes clustered in multiple pathways including cytokine signaling, mRNA processing, endosomal trafficking, and protein metabolism. Genes can exhibit lymphoma subtype- or tumor-specific MHC-I regulation, and a majority of primary DLBCL tumors displayed genetic alterations in multiple regulators. We established SUGT1 as a major positive regulator of both MHC-I and MHC-II cell surface expression. Further, pharmacological inhibition of two negative regulators of antigen presentation, EZH2 and thymidylate synthase, enhanced DLBCL MHC-I presentation. These and other genes represent potential targets for manipulating MHC-I immunosurveillance in cancers, infectious diseases, and autoimmunity.

Identification of a miRNA based model to detect prognostic subgroups in patients with aggressive B-cell lymphoma

In order to differentiate prognostic subgroups of patients with aggressive B-cell lymphoma, we analyzed the expression of 800 miRNAs with the NanoString nCounter human miRNA assay on a cohort of 228 FFPE samples of patients enrolled in the RICOVER-60 and MegaCHOEP trials. We identified significant miRNA signatures for overall survival (OS) and progression-free survival (PFS) by LASSO-penalized linear Cox-regression. High expression levels of miR-130a-3p and miR-423-5p indicate a better prognosis, whereas high levels of miR-374b-5p, miR-590-5p, miR-186-5p, and miR-106b-5p increase patients' risk levels for OS. Regarding PFS high expression of miR-365a-5p in addition to the other two miRNAs improves the prognosis and high levels of miR374a-5p, miR-106b-5p, and miR-590-5p, connects with increased risk and poor prognosis. We identified miRNA signatures to subdivide patients into two different risk groups. These prognostic models may be used in risk stratification in future clinical trials and help making personalized therapy decisions.

Comparative analysis of gene expression platforms for cell-of-origin classification of diffuse large B-cell lymphoma shows high concordance

Cell-of-origin subclassification of diffuse large B cell lymphoma (DLBCL) into activated B cell-like (ABC), germinal centre B cell-like (GCB) and unclassified (UNC) or type III by gene expression profiling is recommended in the latest update of the World Health Organization's classification of lymphoid neoplasms. There is, however, no accepted gold standard method or dataset for this classification. Here, we compare classification results using gene expression data for 68 formalin-fixed paraffin-embedded DLBCL samples measured on four different gene expression platforms (Illumina wG-DASL^TM arrays, Affymetrix PrimeView arrays, Illumina TrueSeq RNA sequencing and the HTG EdgeSeq DLBCL Cell of Origin Assay EU using an established platform agnostic classification algorithm (DAC) and the classifier native to the HTG platform, which is CE marked for in vitro diagnostic use (CE-IVD). Classification methods and platforms show a high level of concordance, with agreement in at least 80% of cases and rising to much higher levels for classifications of high confidence. Our results demonstrate that cell-of-origin classification by gene expression profiling on different platforms is robust, and that the use of the confidence value alongside the classification result is important in clinical applications.

Lymphocyte-to-Monocyte Ratio May Serve as a Better Prognostic Indicator Than Tumor-associated Macrophages in DLBCL Treated With Rituximab

There are multiple prognostic indicators for diffuse large B-cell lymphoma (DLBCL) including the international prognostic index (IPI), and gene expression profiling (GEP) to classify the disease into germinal center B-cell and activated B-cell subtypes, the latter harboring inferior prognosis. More recently, tumor-associated macrophages (TAM) and lymphocyte-to-monocyte ratio (LMR) were found to have prognostic implications in DLBCL. However, consensus is yet to be reached in terms of the significance of each. In this study, we evaluated the prognostic value of TAM as assessed by CD163 or CD68 positivity by immunohistochemistry on tissue biopsies and LMR was calculated from peripheral blood differential, with focus on the inclusion of rituximab as a treatment modality. The number of CD68-positive cells in the tumor microenvironment did not exhibit significant prognostic value, whereas higher number of CD163-positive cells was associated with inferior overall survival in patients treated with chemotherapy alone. This effect was no longer evident in patients treated with rituximab containing chemoimmunotherapy. In contrast, the prognostic significance of LMR on survival was more persistent regardless of treatment. There was no association between LMR and the number of CD163-positive cells. Our results suggest that LMR is the more easily and widely available prognostic marker in this era of chemoimmunotherapy. Our finding supports previous literature that the effect of TAM can vary according to treatment. Interaction between rituximab and TAM warrant further scientific investigation for mechanistic insights into targeted therapeutics.

Diffuse Large B-Cell Lymphoma in Kenya: MYC, BCL2, and the Cell of Origin

PURPOSE

Diffuse large B-cell lymphoma (DLBCL) is the most commonly diagnosed non-Hodgkin lymphoma in adults in Kenya. Cell of origin (COO) and double expression of MYC and BCL2 are two important prognostic factors for DLBCL. A small subset (5% to 10%) of DLBCL cases show positivity for CD5 and are associated with poor prognosis, whereas CD30 antigen, seen in up to 10% of cases, may be a useful target for therapy. We sought to determine the prevalence of MYC/BCL2 double expression, COO, and proportion of Epstein-Barr virus positivity among patients with DLBCL diagnosed at a tertiary referral laboratory in Kenya.

PATIENTS AND METHODS

All cases of DLBCL diagnosed from 2012 through 2015 in our pathology department were analyzed. Tumor tissue microarray sections were stained with CD20, CD3, CD5, CD30, BCL2, BCL6, CD10, MUM1, MYC, and Ki67, classified for COO on the basis of the Hans algorithm, and subjected to Epstein-Barr virus-encoded small RNAs in situ hybridization.

RESULTS

Among 165 DLBCL cases, the median age was 50 years, and there was no sex predilection. Only 18 (10.9%) cases showed double expression for MYC and BCL2. Germinal center B (GCB)-cell type DLBCL accounted for 67 cases (40.6%) and 97 cases (59.4%) were classified as non-GCB. The mean Ki67 proliferation index was significantly higher in the double-expressing (45%) and non-GCB groups (36%) compared with the non–double-expressing group (29%) and GCB group (26%). Sixteen cases (9.7%) were Epstein-Barr virus-encoded small RNAs positive, 12 (75%) of which were non-GCB.

CONCLUSION

DLBCL in Kenya is seen in much younger patients with the poor prognostic non–GCB-type accounting for 59.4% of cases. MYC and BCL2 double expression was seen in fewer tumors than reported in the literature and in significantly older patients.

COO and MYC/BCL2 status do not predict outcome among patients with stage I/II DLBCL: a retrospective multicenter study

In advanced-stage diffuse large B-cell lymphoma (DLBCL), the presence of an activated B-cell phenotype or a non-germinal center (GCB) phenotype, coexpression of MYC and BCL2 by immunohistochemistry, and the cooccurrence of MYC and BCL2 or BCL6 rearrangements are associated with inferior outcomes. It is unclear whether these variables remain prognostic in stage I/II patients. In this retrospective study, we evaluated the prognostic impact of cell of origin (COO), as well as dual-expressor (DE) status and molecular double-hit (DH) status, in stage I/II DLBCL by positron emission tomography with computed tomography (PET-CT). A total of 211 patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone)-like regimens, with or without radiotherapy, was included. The median follow-up in the entire cohort was 4 years (range, 0.4-9.4), with estimated 4-year progression-free survival (PFS) and overall survival (OS) rates of 85% (95% confidence interval [CI], 79-89) and 88% (95% CI, 83-92), respectively. By univariable analysis, DE (PFS: hazard ratio [HR], 1.27; 95% CI, 0.58-2.81, P = .55 and OS: HR, 1.40; 95% CI, 0.60-3.30; P = .44), DH (PFS: HR, 1.21; 95% CI, 0.27-5.31; P = .80 and OS: HR, 0.61; 95% CI, 0.08-4.73; P = .64), and non-GCB status (PFS: HR, 1.59; 95% CI, 0.83-3.03; P = .16 and OS: HR, 1.80; 95% CI, 0.89-3.67; P = .10) were associated with poorer outcomes. In patients with PET-CT-defined stage I/II DLBCL treated with R-CHOP-like therapy, with or without radiation, COO and DE and DH status were not significantly associated with inferior PFS or OS.

Primary Cutaneous DLBCL Non-GCB Type: Challenges of a Rare Case

Several types of B-cell lymphomas, including both primary cutaneous lymphomas and systemic lymphomas, may affect the skin, with partially overlapping clinical, morphological and immunohistochemical features. Currently, the World Health Organization (WHO) classification of primary cutaneous B-cell lymphomas does not include diffuse large B-cell lymphomas (DLBCL) and considers leg-type DLBCL the only primary cutaneous DLBCL. Here we report the case of a 72-year-old white woman with a primary cutaneous neoplasm comprised of large cells with round nuclei, irregularly clumped chromatin and one or more inconspicuous nucleoli. The immunohistochemistry demonstrated positivity for CD20 and MUM1, with no significant genetic translocations detected by fluorescence in-situ hybridization. After staging, we considered this neoplasm a primary cutaneous DLBCL with a non-germinal center phenotype, not otherwise specified, inconsistent with a leg-type DLBCL. Because of this view, we underscore the need for greater knowledge of the molecular landscape of B-cell lymphomas in order to reconsider the classification of such neoplasms in the skin.

New biomarkers in non-Hodgkin lymphoma and acute leukemias

Biomarkers play a critical role in the medical care of patients with cancer, including in early detection of the disease, diagnostic accuracy, risk stratification, treatment, and follow-up. Biomarkers in hematological malignancies can support the redefinition of the diagnosis and adjustments in the treatment plan. Biomarkers can be classified into 4 categories: (1) protein antigens, (2) cytogenetic abnormalities, (3) genetic polymorphisms, and (4) gene expression. Efforts in genomics, proteomics, and metabolomics to observe new biomarkers that contribute to the development of clinical medicine with greater precision in the strategies that improve prevention, diagnosis, and treatment of patients with malignant hematological disease. New biomarkers should accomplish several issues such as the biological plausibility, methodology used, analytical validation, intellectual property registry, and legal framework of application. This knowledge should be transferred to health professionals who can carry out the process of its implementation in clinical practice.

Pathogenic B-cell receptor signaling in lymphoid malignancies: New insights to improve treatment

Signals emanating from the B-cell receptor (BCR) promote proliferation and survival in diverse forms of B-cell lymphoma. Precision medicine strategies targeting the BCR pathway have been generally effective in treating lymphoma, but often fail to produce durable responses in diffuse large B-cell lymphoma (DLBCL), a common and aggressive cancer. New insights into DLBCL biology garnered from genomic analyses and functional proteogenomic studies have identified novel modes of BCR signaling in this disease. Herein, we describe the distinct roles of antigen-dependent and antigen-independent BCR signaling in different subtypes of DLBCL. We highlight mechanisms by which the BCR cooperates with TLR9 and mutant isoforms of MYD88 to drive sustained NF-κB activity in the activated B-cell-like (ABC) subtype of DLBCL. Finally, we discuss progress in detecting and targeting oncogenic BCR signaling to improve the survival of patients with lymphoma.

Naquotinib exerts antitumor activity in activated B-cell-like diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL), the most common type of B-cell non-Hodgkin lymphoma (NHL), is categorized into two major subtypes, activated B-cell-like (ABC) and germinal center B-cell-like (GCB). The ABC subtype is associated with worse prognosis than the GCB subtype using currently available therapies such as combination treatment with rituximab plus standard cytotoxic chemotherapy. The B-cell receptor (BCR) pathway is activated in ABC DLBCL, suggesting that inhibition of this pathway could provide an alternative strategy for treatment. Naquotinib is an irreversible tyrosine kinase inhibitor (TKI) originally designed to target the epidermal growth factor receptor (EGFR). As sequence alignment analysis indicates that irreversible EGFR-TKIs also inhibit Bruton's tyrosine kinase (BTK), here, we characterized the inhibitory effects of naquotinib against BTK in comparison to ibrutinib, acalabrutinib, tirabrutinib and spebrutinib. Naquotinib inhibited BTK kinase activity with similar potency to that for EGFR activating mutations. In vivo, naquotinib induced tumor regression and suppressed tumor recurrence in TMD8 and OCI-Ly10, ABC DLBCL cell line xenograft models, at a lower dose than the clinically relevant dose. Compared to other BTK inhibitors, naquotinib showed faster onset and comparable inhibition of BTK following incubation with cell lines for 3 and 20 h. In addition, naquotinib showed longer continuous inhibition of BTK following removal of the compound, lasting for at least 26 h after removal. Pharmacokinetics studies in the TMD8 xenograft model showed higher concentration and slower elimination of naquotinib in tumors than other BTK inhibitors. These data suggest that naquotinib may have therapeutic potential in ABC DLBCL patients.

Disease characteristics of diffuse large B-cell lymphoma predicting relapse and survival after autologous stem cell transplantation: A single institution experience

While various tools such as the International Prognostic Index (IPI) and its derivatives exist for risk-stratification of diffuse large B-cell lymphoma (DLBCL) at diagnosis, patient and disease characteristics capable of predicting outcome after high-dose chemotherapy followed by autologous stem cell transplantation (HDC/ASCT) are not clearly defined. We retrospectively analyzed medical records of 111 DLBCL patients (78 relapsed and 33 refractory) who underwent HDC/ASCT at our institution from 2010-2015. After a median follow-up time of 4.6 years (interquartile range [IQR] 2.2-8.1), the likelihood of 5-year progression-free survival (PFS) was 62.2% (95% CI, 53.4%-72.4%) and the likelihood of 5-year overall survival (OS) was 68.9% (95% CI, 60.7%-78.2%). More than three chemotherapy regimens prior to ASCT was the only variable associated with lower likelihood of PFS (P = .004) and OS (P = 0.026). Male gender and high IPI score at time of ASCT were also associated with lower likelihood of PFS (P = .043; P = .013). NCCN IPI and age-adjusted IPI at time of ASCT were not predictive of outcome following ASCT. Patients with refractory and relapsed disease had similar outcomes post-ASCT (P = .207 for PFS, P = .073 for OS).

Remaining challenges in predicting patient outcomes for diffuse large B-cell lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma and is an aggressive malignancy with heterogeneous outcomes. Diverse methods for DLBCL outcomes assessment ranging from clinical to genomic have been developed with variable predictive and prognostic success.Areas covered: The authors provide an overview of the various methods currently used to estimate prognosis in DLBCL patients. Models incorporating cell of origin, genomic features, sociodemographic factors, treatment effectiveness measures, and machine learning are described.Expert opinion: The clinical and genetic heterogeneity of DLBCL presents distinct challenges in predicting response to therapy and overall prognosis. Successful integration of predictive and prognostic tools in clinical trials and in a standard clinical workflow for DLBCL will likely require a combination of methods incorporating clinical, sociodemographic, and molecular factors with the aid of machine learning and high-dimensional data analysis.

Single Cell Phenotypic Profiling of 27 DLBCL Cases Reveals Marked Intertumoral and Intratumoral Heterogeneity

Diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype of non-Hodgkin lymphoma and is notorious for its clinical heterogeneity. Patient outcomes can be predicted by cell-of-origin (COO) classification, demonstrating that the underlying transcriptional signature of malignant B-cells informs biological behavior in the context of standard combination chemotherapy regimens. In the current study, we used mass cytometry (CyTOF) to examine tumor phenotypes at the protein level with single cell resolution in a collection of 27 diagnostic DLBCL biopsy specimens from treatment naïve patients. We found that malignant B-cells from each patient occupied unique regions in 37-dimensional phenotypic space with no apparent clustering of samples into discrete subtypes. Interestingly, variable MHC class II expression was found to be the greatest contributor to phenotypic diversity. Within individual tumors, a subset of cases showed multiple phenotypic subpopulations, and in one case, we were able to demonstrate direct correspondence between protein-level phenotypic subsets and DNA mutation-defined subclones. In summary, CyTOF analysis can resolve both intertumoral and intratumoral heterogeneity among primary samples and reveals that each case of DLBCL is unique and may be comprised of multiple, genetically distinct subclones. © 2019 International Society for Advancement of Cytometry.

Cost burden of diffuse large B-cell lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma and is a clinically heterogeneous disease. Treatment pathways for DLBCL are diverse and integrate established and novel therapies.Areas covered: We review the cost burden of DLBCL and the cost-effectiveness of DLBCL management including precision and cellular medicine. We utilized Medical Subject Heading (MeSH) terms and keywords to search the National Library of Medicine online MEDLINE database (PubMed) for articles related to cost, cost burden, and cost-of-illness of DLBCL and cost-effectiveness of DLBCL management strategies published in English as of June 2019.Expert commentary: Available and developing DLBCL therapies offer improved outcomes and often curative treatment at considerable financial expense, and the total cost burden for DLBCL management is substantial for patients and the healthcare system. In the era of personalized medicine, CAR T cells and targeted therapies provide exciting avenues for current and future DLBCL care and can further increase treatment cost. Determinations of cost and cost-effectiveness in DLBCL treatment pathways should continue to guide care providers and systems in identifying cost reduction strategies to provide appropriate therapies to the greatest number of patients in treating DLBCL.

Ancillary Studies in the Diagnostic Evaluation of Large B-Cell Lymphoma

CONTEXT.—

Large B-cell lymphoma classification has changed significantly over the decades, evolving from a purely morphologic categorization to one using sophisticated ancillary studies including molecular analysis, immunohistochemistry, and cytogenetics, in addition to morphology and clinical presentation.

OBJECTIVE.—

To discuss and interpret the key ancillary studies required for subclassification in 2019 and review the differential diagnosis of diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS).

DATA SOURCES.—

Recent literature on the subcategories of large B-cell lymphoma is reviewed, along with relevant updates from the 2016 World Health Organization Classification of Tumours of Hematopoietic and Lymphoid Tissues, with an emphasis on Epstein-Barr virus-positive lymphoproliferative disorders, high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, and large B-cell lymphoma with IRF4 rearrangement.

CONCLUSIONS.—

Cases with DLBCL, NOS histology can be further subclassified on the basis of cell of origin studies, Epstein-Barr virus-encoded small RNAs, MYC and BCL2 and/or BCL6 rearrangement studies, and other relevant cytogenetic and immunohistochemical studies. The diagnosis of DLBCL, NOS is therefore a diagnosis of exclusion.

Front-Line Treatment of High Grade B Cell Non-Hodgkin Lymphoma

PURPOSE OF REVIEW

Rituximab-based chemoimmunotherapy has resulted in a marked improvement in the survival of diffuse large B cell lymphoma (DLBCL). We reflect upon the history front-line (1L) therapy and highlight advances in management.

RECENT FINDINGS

Since the introduction of R-CHOP, the majority of randomized studies in the front-line treatment of DLBCL have failed to show a benefit. Such studies have involved treatment intensification, adding novel agents to the R-CHOP backbone and targeting such novel agents to biologically defined subgroups. R-CHOP therefore remains standard-of-care for most but new insights into the molecular biology of these diseases, and the development of active targeted molecules offers promise for the future. Accumulating evidence in the very elderly suggests dose attenuation does not compromise survival. Intensification in primary mediastinal B cell lymphoma may avoid the need for radiotherapy, but must be balanced against the risks. PET-CT- and ctDNA-based response assessment may now enable response adapted therapy and early prognostication, improving patient selection and potentially outcomes. Novel technologies and therapies in combination with novel molecular diagnostics will likely become the standard-of-care approach for the personalized therapy of DLBCL but need to be proven in well-designed and conducted randomized trials.

Rural and urban patients with diffuse large B-cell and follicular lymphoma experience reduced overall survival: a National Cancer DataBase study

We examined 83,108 patients with diffuse large B-cell lymphoma (DLBCL) and 43,393 patients with follicular lymphoma (FL) to investigate disparities related to geographic population density, stratified as rural, urban, or metropolitan. We found that urban and rural patients less commonly had private insurance and high socioeconomic status. Urban and rural DLBCL patients were more likely to receive treatment within 14 days of diagnosis (OR 0.93, 95% confidence interval [CI] 0.89-0.98; and OR 0.81, 95% CI 0.72-0.91) while urban FL patients were more likely to have treatment >14 days after diagnosis (OR 1.08, 95% CI 1.01-1.16). Multivariable analyses demonstrated that rural and urban patients had worse overall survival with DLBCL (hazard ratio [HR] 1.09; 95% CI 1-1.19 and HR 1.08; 95% CI 1.04-1.11) and FL (HR 1.11; 95% CI 1.04-1.18 and HR 1.2; 95% CI 1.02-1.41), respectively, suggesting needs for focused study and interventions for these populations.

Integrating precision medicine through evaluation of cell of origin in treatment planning for diffuse large B-cell lymphoma

Precision medicine is modernizing strategies for clinical study design to help improve diagnoses guiding individualized treatment based on genetic or phenotypic characteristics that discriminate between patients with similar clinical presentations. Methodology to personalize treatment choices is being increasingly employed in clinical trials, yielding favorable correlations with improved response rates and survival. In patients with diffuse large B-cell lymphoma (DLBCL), disease characteristics and outcomes may vary widely, underscoring the importance of patient classification through identification of sensitive prognostic features. The discovery of distinct DLBCL molecular subtypes based on cell of origin (COO) is redefining the prognosis and treatment of this heterogeneous cancer. Owing to significant molecular and clinical differences between activated B-cell-like (ABC)- and germinal center B-cell-like (GCB)-DLBCL subtypes, COO identification offers opportunities to optimize treatment selection. Widespread adoption of COO classification would greatly improve treatment and prognosis; however, limitations in interlaboratory concordance between immunohistochemistry techniques, cost, and availability of gene expression profiling tools undermine universal integration in the clinical setting. With advanced methodology to determine COO in a real-world clinical setting, therapies targeted to specific subtypes are under development. The focus here is to review applications of precision medicine exemplified by COO determination in DLBCL patients.

Taming the Heterogeneity of Aggressive Lymphomas for Precision Therapy

Genomic analyses of diffuse large B cell lymphoma (DLBCL) are revealing the genetic and phenotypic heterogeneity of these aggressive lymphomas. In part, this heterogeneity reflects the existence of distinct genetic subtypes that acquire characteristic constellations of somatic genetic alterations to converge on the DLBCL phenotype. In parallel, functional genomic screens and proteomic analyses have identified multiprotein assemblies that coordinate oncogenic survival signaling in DLBCL. In this review, we merge these recent insights into a unified conceptual framework with implications for the design of precision medicine trials in DLBCL.

Profiling of lymphoma from formalin-fixed paraffin-embedded tissue

Molecular profiling of lymphoma samples has contributed enormously to our understanding of disease biology leading to detailed descriptions of diagnostic categories. These studies have also helped the field to recognize different subtypes of disease, different diseases that share similar cellular pathway perturbations, different immune responses, and different prognostic groups. While nearly all of these discoveries were made using unfixed, snap-frozen materials, with few exceptions, clinical biopsy materials are comprised of formalin-fixed and paraffin-embedded (FFPE) tissues. Here, we describe the impact of molecular profiling on the field of lymphoma, the challenges associated with using FFPE tissues for downstream molecular diagnostic testing, the various molecular profiling techniques, and also provide an example of the clinical application of a molecular profiling test of lymphoma using FFPE tissues.

Dissecting aggressive B-cell lymphoma through genomic analysis - What is clinically relevant?

The aggressive B-cell lymphomas are a diverse collection of cancers grouped together based on clinical behavior and derivation from B lymphocytes. Genomic analyses on these tumours are now translating into improved classification systems and identification of underpinning targetable biology. Simple karyotyping revealed key translocations involving MYC, BCL2, and BCL6 that have impacted lymphoma classification in the World Health Organization classification scheme. Subsequently, gene expression profiling identified molecular subgroups within the most common lymphoma, diffuse large B-cell lymphoma (DLBCL): activated B-cell-like and germinal centre B-cell-like. Finally, next generation sequencing has revealed a modest number of frequently mutated genes and a long list of infrequent mutations. The mutational landscapes involve diverse genes associated with dysregulated signalling, epigenetic modification, blockade of cellular differentiation, and immune evasion. These mutational "signatures" are enriched in the different aggressive lymphoma subtypes impacting phenotypes and identifying therapeutic targets. Challenges to implementing genomic assays into clinical practice remain.

The cell-of-origin classification of diffuse large B cell lymphoma in a Korean population by the Lymph2Cx assay and its correlation with immunohistochemical algorithms

Cell-of-origin (COO) classification of diffuse large B cell lymphoma (DLBCL) is increasingly important due to its prognostic significance and the development of subtype-specific therapeutics. We compared the clinical utility of the Lymph2Cx assay against four widely used immunohistochemical algorithms in 150 R-CHOP-treated DLBCL patients using archival tissue. In contrast to the predominance of germinal center B cell-like (GCB) subtype in Western populations, Lymph2Cx assay classified more than half of the Korean cases as the activated B cell-like (ABC) subtype (ABC, 83/150 [55.3%]; GCB, 51/150 [34.0%]; unclassifiable, 16/150 [10.7%]). Predominance of ABC subtype tended to be more pronounced in the nodal lymphomas than in the extranodal lymphomas. However, among the primary extranodal sites, ABC subgroups predominated in primary testicular, breast, and adrenal gland lymphomas. The classification of COO by Lymph2Cx assay did not show any significant association with clinical parameters. The overall concordance rates of the immunohistochemical algorithms with the Lymph2Cx ranged from 78.0 to 84.3%. However, 47.1-66.7% of the cases of the Lymph2Cx-defined GCB subgroup were misclassified as the non-GCB class by the IHC algorithms. The survival of Lymph2Cx-classified COO subtypes was not significantly different in the present cohort. In conclusion, ABC subtype predominated over GCB in Korean patients. There are significant discrepancies between the immunohistochemistry and Lymph2Cx classifications, especially in GCB subtype.

Exploring the potential cost-effectiveness of precision medicine treatment strategies for diffuse large B-cell lymphoma

Activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) is associated with worse survival after standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP) chemoimmunotherapy compared to germinal center B-cell-like (GCB) subtype. Preliminary evidence suggests that benefits from novel agents may vary by subtype. Hypothesizing that treatment stratified by DLBCL subtype could be potentially cost-effective, we developed micro-simulation models to compare three first-line treatment strategies: (1) standard RCHOP for all patients (2) subtype testing followed by RCHOP for GCB and novel treatment for ABC DLBCL, and (3) novel treatment for all patients. Based on phase 2 evidence, we used lenalidomide + RCHOP as a surrogate novel treatment. The subtype-based approach showed a favorable incremental cost-effectiveness ratio of $15,015/quality-adjusted life year compared with RCHOP. Although our exploratory analyses demonstrated a wide range of conditions where subtype-based treatment remained cost-effective, data from phase 3 trials are needed to validate our models' findings and draw definitive conclusions.

Prognostication of diffuse large B-cell lymphoma in the molecular era: moving beyond the IPI

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with variable outcomes. Despite the majority of patients being cured with combination chemoimmunotherapy, up to 30% eventually succumb to the disease. Until recently, baseline prognostic assessment has centred on the International Prognostic Index (IPI), although this index is yet to impact strongly on treatment choice. Molecular features such as cell of origin, MYC and BCL-2 genetic alterations and protein overexpression were identified over a decade ago, yet their prognostic value is still not fully elucidated. Adding complexity are the plethora of new clinical, biological and molecular prognostic markers described in the recent literature, most of which lack independent validation, likely act as surrogate markers for those already in common use and have yet to substantially impact on therapeutic decision making. This review comprehensively assesses the value of individual prognostic markers in the clinical setting and their potential to predict response to novel agents, and ways to optimise their use in future research.

Clinicopathological Analysis of 320 Cases of Diffuse Large B-cell Lymphoma Using the Hans Classifier

The estimation of clinical prognosis for diffuse large B-cell lymphoma (DLBCL) with a quick, cost-efficient method is necessary because of the clinical heterogeneity of this disease, which leads to death, relapsed or refractory disease in approximately 40% of patients. We analyzed 320 cases diagnosed from 2007 to 2013 treated with R-CHOP therapy at Tokai University Hospital and associated institutions. DLBCL was classified according to the cell-of-origin using the Hans algorithm [germinal center B-cell-like (GCB) vs non-GCB subtypes], and into 6 subgroups derived from combinations of CD10, BCL6 and MUM1 markers. The percentage of GCB and non-GCB (NGCB) subtypes was 35% and 65%, respectively. GCB-DLBCL was characterized by lower BCL2 immunohistochemical expression, extranodal sites ＜1, better therapeutic response, and favorable overall survival (OS) and progression free survival (PFS) (P＜0.01). The most frequent subgroup was NGCB-1 (CD10^-BCL6⁺MUM1⁺, 51%) followed by GCB-1 (CD10⁺BCL6^+or-MUM1⁺, 21%), NGCB-2 (CD10^-BCL6^-MUM1⁺, 13%), GCB-2 (CD10⁺BCL6^+or-MUM1^-, 10%), GCB-3 (CD10^-BCL6⁺MUM1^-, 4%) and NGCB-3 (CD10^-BCL6^-MUM1^-, 2%). In comparison with GCB-2 and GCB-3 (both MUM1^-), the GCB-1 (MUM1⁺) was characterized by favorable PFS (5-year PFS 84% vs 65%, OR 0.368, P＜0.05), independent of high LDH (associated with unfavorable PFS, OR 7.04, P＜0.01) in the multivariate analysis. This predictive value of MUM1 was independent of CD10. Interestingly, triple-negative NGCB-3 tended to have a more favorable prognosis than the other NGCB subgroups. In conclusion, the Hans classifier is a valid method to evaluate the prognosis of DLBCL NOS. In the GCB subtypes, GCB subtypes, MUM1-positivity is associated with a more favorable outcome (PFS).

Informatics Approaches to Address New Challenges in the Classification of Lymphoid Malignancies

Purpose

Lymphoid malignancies are remarkably heterogeneous, with variations in outcomes and clinical, biologic, and histologic presentation complicating classification according to the World Health Organization guidelines. Incorrect classification of lymphoid neoplasms can result in suboptimal therapeutic strategies for individual patients and confound the interpretation of clinical trials involving personalized, class-based treatments. This review discusses the potential role of pathology informatics in improving the classification accuracy and objectivity for lymphoid malignancies.

Design

We identified peer-reviewed publications examining pathology informatics approaches for the classification of lymphoid malignancies, reviewed developments in the lymphoma classification systems, and summarized computational methods for pathologic assessment that can impact practice.

Results

Computer-assisted pathology image analysis algorithms in lymphoma most commonly have been applied to follicular lymphoma to address biologic heterogeneity and subjectivity in the process of classification.

Conclusion

Objective methods are available to assist pathologists in lymphoma classification and grading, and have been demonstrated to provide measurable benefits in specific contexts. Future validation and extension of these approaches will require datasets that link high resolution pathology images available for image analysis algorithms with clinical variables and follow up outcomes.

Combination of baseline FDG PET/CT total metabolic tumour volume and gene expression profile have a robust predictive value in patients with diffuse large B-cell lymphoma

PURPOSE

This study evaluated the predictive significance of total metabolic tumour volume (TMTV) measured on baseline FDG PET/CT and its value in addition to gene expression profiling using a new method of gene analysis (rapid reverse transcriptase multiplex ligation-dependent probe amplification assay, RT-MLPA) in patients with diffuse large B-cell lymphoma treated with R-CHOP or R-CHOP-like chemotherapies.

METHODS

The analysis included 114 patients. TMTV was measured using a 41% SUVmax threshold and tumours were classified into GCB or ABC subtypes according to the RT-MLPA assay.

RESULTS

The median follow-up was 40 months. the 5-year progression-free survival (PFS) was 54% and the 5-year overall survival (OS) was 62%. The optimal TMTV cut-off value was 261 cm³. In 59 patients with a high TMTV the 5-year PFS and OS were 37% and 39%, respectively, in comparison with 72% and 83%, respectively, in 55 patients with a low TMTV (p = 0.0002 for PFS, p < 0.0001 for OS). ABC status was significantly associated with a worse prognosis. TMTV combined with molecular data identified three groups with very different outcomes: (1) patients with a low TMTV whatever their phenotype (n = 55), (2) patients with a high TMTV and GCB phenotype (n = 33), and (3) patients with a high TMTV and ABC phenotype (n = 26). In the three groups, 5-year PFS rates were 72%, 51% and 17% (p < 0.0001), and 5-year OS rates were 83%, 55% and 17% (p < 0.0001), respectively. In multivariate analysis, TMTV, ABC/GCB phenotype and International Prognostic Index were independent predictive factors for both PFS and OS (p < 0.05 for both).

CONCLUSIONS

This integrated risk model could lead to more accurate selection of patients that would allow better individualization of therapy.

Lymphoproliferative Diseases of the Gut: A Survival Guide for the General Pathologist

The gastrointestinal tract is the most common extranodal site of involvement by lymphoma, with B-cell tumors outnumbering T-cell tumors by a wide margin. Diffuse large B-cell lymphoma is the most common lymphoid neoplasm involving the gastrointestinal tract; but a variety of other B- and T-cell neoplasms occur in the gastrointestinal organs, often with characteristic associations and/or manifestations. Although the diagnosis of gastrointestinal lymphomas can sometimes seem daunting to general pathologists, a knowledge of the most commonly encountered entities, in combination with a reasoned and pragmatic approach to the diagnostic workup, makes it possible to approach most cases with confidence.

Prognostic modeling in diffuse large B-cell lymphoma in the era of immunochemotherapy: Where do we go from here?

The model and approach described by Howlader et al could form a foundation for future risk‐prediction models that incorporate data on known differences in demographic, socioeconomic, clinical, and biological factors. Data from large diffuse large B‐cell lymphoma patient cohorts that capture host and tumor genomics and known clinical prognostic factors will be necessary to provide the resources for constructing meaningful prognostic models and to establish prediction models that will allow us to limit therapy and therapy‐related toxicity for favorable subsets of patients while optimizing directed approaches for poor‐risk subsets.

See also pages 3326‐34.