Are we ready to stratify treatment for diffuse large B-cell lymphoma using molecular hallmarks?

microRNA sequencing for biomarker detection in the diagnosis, classification and prognosis of Diffuse Large B Cell Lymphoma

Despite being considered a single disease, Diffuse Large B Cell Lymphoma (DLBCL) presents with variable backgrounds, which results in heterogeneous outcomes among patients, with 40% of them still having primary refractory disease or relapse. Thus, novel biomarkers are needed. In addition, multiple factors regarding its pathogenesis remain unclear. In this context, recent investigations point to the relevance of microRNAs (miRNAs) in cancer. However, regarding DLBCL, there is inconsistency in the data reported. Therefore, in this work, the main goals were to determine a miRNA set with utility as biomarkers for DLBCL diagnosis, classification, prognosis and treatment response, as well as to decipher the mechanism of action of deregulated miRNAs in the origin of the disease. We analyzed miRNA expression in a cohort of 78 DLBCL patients and 17 controls using small RNA sequencing and performed a miRNA-mRNA interaction network analysis. This way, we were able to define new miRNA expression signatures for diagnosis, classification, treatment response and prognosis, and we identified plausible mechanisms of action by which deregulated miRNAs could be involved in DLBCL pathogenesis. In summary, our study remarks that miRNAs could play an important role in DLBCL.

Primary central nervous system lymphoma: Comprehension of cell-of-origin subtypes

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is an uncommon extranodal lymphoma that accounts for more than 95% of all the CNS lymphomas. Unlike its systemic/nodal counterpart, which is currently subtyped into cell-of origin (COO) subtypes, its feasibility and utility are largely debatable in PCNS-DLBCL.

Objectives

To classify PCNS-DLBCL into COO-subtypes based on immunohistochemical algorithms by Hans and Choi and evaluate concordance between the two. A further aim is to investigate the clinicoradiological and histomorphological parameters of the subtypes thus obtained.

Materials and Methods

As many as 143 cases of primary CNS lymphoma were evaluated by immunohistochemistry for CD10, BCL6, MUM1, GCET, and FOXP1 and based on which the said 143 cases were further classified into COO subtypes using Hans and Choi algorithms.

Results

Mean age was 53.8 years with marginal male preponderance and predominantly centroblastic morphology (75.5%). CD 10 was positive in 8.9% of the cases, BCL6 in 58.6%, MUM1 in 89.9%, GCET in 32.9%, and FOXP1 in 79.5%. As much as 84.9% cases were of non-germinal center B-cell (GCB) subtype and 15.1% cases were of GCB subtype as determined based on Hans algorithm. Furthermore, 90.7% cases were of activated B-cell (ABC) subtype and 9.3% cases were of GCB subtype according to Choi algorithm. A 91.8% concordance was observed between Hans and Choi algorithms. Among the 6 discordant cases, 5 cases were subtyped as GCB by Hans and ABC by Choi and 1 case as ABC by Hans and GCB by Choi.

Conclusion

Most of PCNS-DLBCLs are of non-GCB/ABC COO subtype, but inconsistences abound in the utility of IHC algorithms in PCNS-DLBCL COO subtypes.

Application of next-generation sequencing in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of invasive non-Hodgkin lymphoma. There is great heterogeneity in its molecular biological characteristics, clinical manifestations and prognosis. The use of rituximab has greatly improved the cure rate of DLBCL, but there are still 30% of patients with poor prognosis. In the era of precision medicine, the significance of molecular biology and genetic factors on the diagnosis, treatment and prognosis of patients has been found. Among these, next-generation sequencing technology plays an important role. This paper reviews the research progress of next-generation sequencing technology in the classification, diagnosis, prognosis and molecular targeted therapy of DLBCL.

Comparison of the Lymph2Cx Assay and Hans Algorithm in Determining the Cell-of-Origin of Diffuse Large B-Cell Lymphomas, Not Otherwise Specified

In the era of precision medicine, accurate and reproducible assignment of cell-of-origin (COO) in diffuse large B-cell lymphoma patients has become important. The Lymph2Cx assay is accurately determining COO by analyzing RNA expression of 20 selected genes while the Hans algorithm based on immunohistochemistry is the most popular method for routine daily diagnosis. However, there are discrepancies between the 2 methods, which need to be evaluated for better correlation. We prospectively analyzed 156 cases of diffuse large B-cell lymphoma, not otherwise specified to analyze the characteristics of discrepancy groups of COO determined by Lymph2Cx and Hans algorithm. We investigated the pattern and cause of discrepancy of COO assigned by the 2 methods. Hans algorithm classified 50 cases (32%) as germinal-center B-cell-like (GCB) type and 106 cases (68%) as non-GCB type. Lymph2Cx assay assigned 43 cases (28%) as GCB type, 94 cases (60%) as activated B-cell-like type, and 19 cases (12%) as intermediate/unclassified type. The agreement rate was 86% after exclusion of unclassified type. With regard to the clinicopathologic factors related with discrepancy between Hans algorithm and Lymph2Cx assay, endoscopic biopsy of the gastrointestinal tract (4/11, 36%) showed higher discrepancy rate (P=0.052). Immunophenotypically, CD10/BCL6/MUM1 GCB type and CD10/BCL6//MUM1 (=30%, low level expression) non-GCB type exhibited a significantly higher discrepancy rate (6/13, 46%; 4/13, 31%) (P=0.0001). Activated B-cell-like subgroup via Lymph2Cx assay predicted poor progression-free survival (mean survival duration 28.6 mo, P=0.049) compared with the GCB and unclassified type. Hans algorithm revealed no significant difference in progression-free survival and overall survival (P=0.122 and 0.121). These results suggest that when assigning COO via Hans algorithm, CD10/BCL6/MUM1 GCB type and CD10/BCL6/MUM1 (=30%, low level) non-GCB type require careful interpretation, especially if the MUM1 staining is weak and heterogeneous in the biopsied specimen.

Value of total lesion glycolysis and cell-of-origin subtypes for prognostic stratification of diffuse large B-cell lymphoma patients

Background

This study aimed to explore the added prognostic value of baseline metabolic volumetric parameters and cell of origin subtypes to the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) in nodal diffuse large B-cell lymphoma (DLBCL) patients.

Methods

A total of 184 consecutive de novo nodal DLBCL patients who underwent baseline positron emission tomography/computed tomography (PET/CT) were included in this study. Kaplan-Meier estimates were generated to evaluate the clinical, biological, and PET/CT parameters' prognostic value. The Cox proportional hazards model was performed to examine the potential independent predictors for progression-free survival (PFS) and overall survival (OS).

Results

With a median follow-up of 35 months, the 3-year PFS and OS were 65.2% and 73.0%, respectively. In univariate analysis, total lesion glycolysis (TLG), cell-of-origin subtypes, and NCCN-IPI were both PFS and OS predictors. High TLG (≥1,852), non-germinal center B (non-GCB), as well as high NCCN-IPI (≥4), were shown to be independently significantly associated with inferior PFS and OS after multivariate analysis. Based on the number of risk factors (high TLG, non-GCB, and high NCCN-IPI), a revised risk model was designed, and the participants were divided into four risk groups with very different outcomes, in which the PFS rates were 89.7%, 66.2%, 51.7%, and 26.7% (χ²=30.179, P<0.001), and OS rates were 93.1%, 73.8%, 56.7%, and 43.3%, respectively (χ²=23.649, P<0.001), respectively. Compared with the NCCN-IPI alone, the revised risk model showed a stronger ability to reveal further discrimination among subgroups, especially for participants with very unfavorable survival outcomes (PFS: χ²=9.963, P=0.002; OS: χ²=4.166, P=0.041, respectively).

Conclusions

The TLG, cell-of-origin subtypes, and NCCN-IPI are independent prognostic survival factors in DLBCL patients. Moreover, the revised risk model composed of the number of risk factors (high TLG, non-GCB, and high NCCN-IPI) can stratify patients better than the NCCN-IPI, especially for patients at high risk, which suggests its potential integration into decision making for personalized medicine.

Genomics of diffuse large B cell lymphoma

Next generation sequencing (NGS) technology has revealed the heterogeneity of diffuse large B-cell lymphoma (DLBCL) from a mutation perspective. Accordingly, the conventional cell of origin-based classification of DLBCL has changed to a mutation-based classification. Mutation analysis delineates that B-cell receptor pathway activation, EZH2 mutation, and NOTCH mutations are distinctive drivers of DLBCL. Moreover, the combination of RNA expression data and DNA mutation results suggests similarity between DLBCL subtypes and other non-Hodgkin lymphomas. NGS-based dissection of DLBCL would be the cornerstone for precision treatment in this heterogeneous disease in the near future.

Activity of ibrutinib plus R-CHOP in diffuse large B-cell lymphoma: Response, pharmacodynamic, and biomarker analyses of a phase Ib study

INTRODUCTION

This unplanned post-hoc analysis was based on data from the phase Ib DBL1002 study (NCT01569750) and evaluated the association between molecular biomarkers and clinical response to combined treatment with ibrutinib plus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in diffuse large B-cell lymphoma (DLBCL) subtypes.

METHODS

DLBCL subtyping was conducted using immunohistochemistry. Next-generation sequencing using immunoglobulin H primers assessed minimal residual disease (MRD). A quantitative assay evaluated Bruton's tyrosine kinase (BTK) occupancy by ibrutinib in peripheral blood mononuclear cells. Targeted DNA sequencing examined genetic variants by DLBCL subtype. Secreted protein expression was evaluated with a SomaLogic analyte panel.

RESULTS

Among 21 patients with DLBCL (median age 53.5 years), 17 achieved a complete response (CR) and 4 a partial response (PR). Of the 11 subtyped patients, 9 had a CR (5/7 germinal center B-cell-like [GCB] and 4/4 non-GCB) and 2 had a PR (both GCB). Nine of 12 patients tested for MRD achieved early (cycle 2 day 1) MRD negativity; most had a CR. There was near-complete BTK occupancy at 4 h postdose. Mutation analysis (n = 19) revealed variants including CREBBP, KMT2D, LRP1B, BCL2, and TNFRSF14; only 1 CD79B and TP53 each; no CARD11 or MYD88.

CONCLUSIONS

In this study, first-line ibrutinib plus R-CHOP benefited patients with DLBCL, with good overall response rate and early MRD negativity. With a caveat of small sample size, our results showed that a favorable genetic profile and younger patient age may be important to beneficial clinical outcome with ibrutinib plus R-CHOP in DLBCL.

Diffuse large B-cell lymphoma in Southeast Asian cohort: expression patterns of B-cell receptor (BCR) repertoire and its linkage with molecular subtypes and response to R-CHOP therapy

AIMS

Heightened B-cell receptor (BCR) activity in diffuse large B-cell lymphoma (DLBCL) is well established, and a subset of patients with relapsed DLBCL can benefit from BCR-targeted therapies. Universal outreach of such emerging therapies mandates forming a global landscape of BCR molecular signalling in DLBCL, including Southeast Asia.

METHODS

79 patients with DLBCL (nodal, 59% and extranodal, 41%) treated with rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) therapy were selected. Expression levels of BCR and linked signalling pathway molecules were inter-related with Lymph2Cx-based cell of origin (COO) types and overall survival (OS).

RESULTS

Activated B-cell (ABC) type DLBCL constituted 49% (39/79) compared with germinal centre B-cell (GCB) type DLBCL (29/79; 37%) and revealed poor prognosis (p=0.013). In ABC-DLBCL, high BTK expression exerted poor response to R-CHOP, while OS in ABC-DLBCL with low BTK expression was similar to GCB-DLBCL subtype (p=0.004). High LYN expression coupled with a poor OS for ABC-DLBCL as well as GCB-DLBCL subtypes (p=0.001). Furthermore, high coexpression of BTK/LYN (BTK ^high/LYN ^high) showed poor OS (p=0.019), which linked with upregulation of several genes associated with BCR repertoire and nuclear factor-kappa B pathway (p<0.01). In multivariate analysis, high BTK and LYN expression retained prognostic significance against established clinical predictive factors such as age, International Prognostic Index and COO (p<0.05).

CONCLUSIONS

Our data provide a clear association between high BCR activity in DLBCL and response to therapy in a distinct population. Molecular data provided here will pave the pathway for the provision of promising novel-targeted therapies to patients with DLBCL in Southeast Asia.

Retrospective Analysis of a New Prognostic Score for Diffuse Large B-Cell Lymphoma Based on Interim Positron Emission Tomography-Computed Tomography

BACKGROUND

The International Prognostic Index (IPI) scoring system is the most widely used prognostic tool for diffuse large B-cell lymphoma (DLBCL); however, it fails to consistently identify patients with poor outcomes. This retrospective study was undertaken to confirm the clinical value of a new prognostic score and compare it with the IPI.

METHODS

The aim of this single-center study was to confirm the clinical value of a new prognostic score and its association with various clinical features, disease progression, and death in 70 patients with DLBCL who had undergone at least 6 cycles of chemotherapy.

RESULTS

The IPI and the new prognostic index were both associated with 3-year mortality (p ≤ 0.032); however, only the new prognostic index was associated with 3-year progression (p ≤ 0.036). Multivariate analysis showed that the new prognostic index was associated with 3-year progression but not overall survival. The new prognostic score also distinguished 3-year progression-free survival and overall survival in the low- and low-intermediate-risk groups as well as in the low-intermediate- and high-intermediate-risk groups.

CONCLUSIONS

The new prognostic score represents a comprehensive prognostic model superior to the IPI. Prospective studies are necessary to explore whether treatment strategies may be adjusted using this new prognostic score.

Cell-of-origin of diffuse large B-cell lymphomas determined by the Lymph2Cx assay: better prognostic indicator than Hans algorithm

Diffuse large B-cell lymphomas (DLBCLs) are clinically heterogeneous and need a biomarker that can predict the outcome of treatments accurately. To assess the prognostic significance of the cell-of-origin type for DLBCLs, we applied the Lymph2Cx assay using a NanoString gene expression platform on formalin-fixed paraffin wax-embedded pretreatment tissues obtained from 82 patients with de novo DLBCL, not otherwise specified. All patients were treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as the first line of chemotherapy. Based on the expression levels of Bcl-6, CD10, and MUM-1 measured by immunohistochemistry, cases were subdivided into germinal center B-cell (GCB) and non-GCB types according to the Hans algorithm. NanoString assay was performed on 82 cases. The Lymph2Cx assay successfully classified 82 cases into three categories: activated B-cell (ABC), GCB, and unclassified types. The concordance rate between the Lymph2Cx assay and the Hans algorithm was 73.6%. The Lymph2Cx-defined ABC type had significantly poorer outcomes compared with the GCB type (5-year overall survival, GCB vs. ABC, 96.6% vs. 77.1%, P = 0.020; 5-year disease-free survival, GCB vs. ABC, 96.6% vs. 79.2%, P = 0.018). In contrast, no significant differences were observed in survival between the two patient subgroups with DLBCL types classified by the Hans algorithm. The Lymph2Cx assay is a robust, reliable method for predicting the outcome of patients with DLBCL treated with R-CHOP chemotherapy.

Comparison of protein-based cell-of-origin classification to the Lymph2Cx RNA assay in a cohort of diffuse large B-cell lymphomas in Malaysia

Aims

The cell of origin (COO) based molecular characterisation into germinal centre B-cell-like (GCB) and activated B-cell-like (ABC) subtypes are central to the pathogenesis and clinical course in diffuse large B-cell lymphoma (DLBCL). Globally, clinical laboratories employ pragmatic but less than ideal immunohistochemical (IHC) assay for COO classification. Novel RNA-based platforms using routine pathology samples are emerging as new gold standard and offer unique opportunities for assay standardisation for laboratories across the world. We evaluated our IHC protocols against RNA-based technologies to determine concordance; additionally, we gauged the impact of preanalytical variation on the performance of Lymph2Cx assay.

Methods

Diagnostic biopsies (n=104) were examined for COO classification, employing automated RNA digital quantification assay (Lymph2Cx). Results were equated against IHC-based COO categorisation. Assay performance was assessed through its impact on overall survival (OS).

Results

96 (92%) informative samples were labelled as GCB (38/96; 40%) and non-GCB (58/96; 60%) by IHC evaluation. Lymph2Cx catalogued 36/96 (37%) samples as GCB, 45/96 (47%) as ABC and 15/96 (16%) as unclassified. Lymph2Cx being reference, IHC protocol revealed sensitivity of 81% for ABC and 75% for GCB categorisation and positive predictive value of 81% versus 82%, respectively. Lymph2Cx-based COO classification performed superior to Hans algorithm in predicting OS (log rank test, p=0.017 vs p=0.212).

Conclusions

Our report show that current IHC-based protocols for COO classification of DLBCL at UKM Malaysia are in line with previously reported results and marked variation in preanalytical factors do not critically impact Lymph2Cx assay quality.

Expression patterns of the activator protein-1 (AP-1) family members in lymphoid neoplasms

The activator protein-1 (AP-1) is a dimeric transcription factor composed of proteins belonging to the Jun (c-Jun, JunB and JunD), Fos (c-Fos, FosB, Fra1 and Fra2) and activating transcription factor protein families. AP-1 is involved in various cellular events including differentiation, proliferation, survival and apoptosis. Deregulated expression of AP-1 transcription factors is implicated in the pathogenesis of various lymphomas such as classical Hodgkin lymphomas, anaplastic large cell lymphomas, diffuse large B cell lymphomas and adult T cell leukemia/lymphoma. The main purpose of this review is the analysis of the expression patterns of AP-1 transcription factors in order to gain insight into the histophysiology of lymphoid tissues and the pathology of lymphoid malignancies.

Role of Rituximab and Rituximab Biosimilars in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL), an aggressive non-Hodgkin lymphoma (NHL), is the most-common subtype of NHL. DLBCL can be classified into at least 3 major immunologically distinct types, which contributes to considerable variation in disease prognosis and response to treatment. DLBCL potentially is curable, even when diagnosed at advanced stages. The current standard of care for most patients with untreated or relapsed/refractory DLBCL is chemoimmunotherapy containing rituximab, an anti-CD20 monoclonal antibody. With advanced understanding of the molecular mechanisms involved in the pathogenesis of DLBCL and specific signaling pathways that are activated in different subtypes, potential new therapeutic targets have been identified, some of which are at the late stages of clinical development. This review summarizes the critical role of rituximab in the current standard of care treatment for DLBCL and discusses why rituximab is likely to remain an important component of treatment options for DLBCL in the foreseeable future. In addition, current and emerging therapeutic agents, including potential benefits of rituximab biosimilars, for patients with DLBCL are discussed. The advent of rituximab biosimilars may facilitate accessibility of rituximab-based chemotherapies to patients with DLBCL and has potential cost-saving benefits for healthcare systems globally.

Translating cancer genomes and transcriptomes for precision oncology

Understanding the molecular landscape of cancer has facilitated the development of diagnostic, prognostic, and predictive biomarkers for clinical oncology. Developments in next-generation DNA sequencing technologies have increased the speed and reduced the cost of sequencing the nucleic acids of cancer cells. This has unlocked opportunities to characterize the genomic and transcriptomic landscapes of cancer for basic science research through projects like The Cancer Genome Atlas. The cancer genome includes DNA-based alterations, such as point mutations or gene duplications. The cancer transcriptome involves RNA-based alterations, including changes in messenger RNAs. Together, the genome and transcriptome can provide a comprehensive view of an individual patient's cancer that is beginning to impact real-time clinical decision-making. The authors discuss several opportunities for translating this basic science knowledge into clinical practice, including a molecular classification of cancer, heritable risk of cancer, eligibility for targeted therapies, and the development of innovative, genomic-based clinical trials. In this review, key applications and new directions are outlined for translating the cancer genome and transcriptome into patient care in the clinic.

Cross-platform assessment of genomic imbalance confirms the clinical relevance of genomic complexity and reveals loci with potential pathogenic roles in diffuse large B-cell lymphoma

Genomic copy number alterations (CNAs) in diffuse large B-cell lymphoma (DLBCL) have roles in disease pathogenesis, but overall clinical relevance remains unclear. Herein, an unbiased algorithm was uniformly applied across three genome profiling datasets comprising 392 newly-diagnosed DLBCL specimens that defined 32 overlapping CNAs, involving 36 minimal common regions (MCRs). Scoring criteria were established for 50 aberrations within the MCRs while considering peak gains/losses. Application of these criteria to independent datasets revealed novel candidate genes with coordinated expression, such as CNOT2, potentially with pathogenic roles. No one single aberration significantly associated with patient outcome across datasets, but genomic complexity, defined by imbalance in more than one MCR, significantly portended adverse outcome in two of three independent datasets. Thus, the standardized scoring of CNAs currently developed can be uniformly applied across platforms, affording robust validation of genomic imbalance and complexity in DLBCL and overall clinical utility as biomarkers of patient outcome.

Whole-exome analysis reveals novel somatic genomic alterations associated with outcome in immunochemotherapy-treated diffuse large B-cell lymphoma

Lack of remission or early relapse remains a major clinical issue in diffuse large B-cell lymphoma (DLBCL), with 30% of patients failing standard of care. Although clinical factors and molecular signatures can partially predict DLBCL outcome, additional information is needed to identify high-risk patients, particularly biologic factors that might ultimately be amenable to intervention. Using whole-exome sequencing data from 51 newly diagnosed and immunochemotherapy-treated DLBCL patients, we evaluated the association of somatic genomic alterations with patient outcome, defined as failure to achieve event-free survival at 24 months after diagnosis (EFS24). We identified 16 genes with mutations, 374 with copy number gains and 151 with copy number losses that were associated with failure to achieve EFS24 (P<0.05). Except for FOXO1 and CIITA, known driver mutations did not correlate with EFS24. Gene losses were localized to 6q21-6q24.2, and gains to 3q13.12-3q29, 11q23.1-11q23.3 and 19q13.12-19q13.43. Globally, the number of gains was highly associated with poor outcome (P=7.4 × 10⁻¹²) and when combined with FOXO1 mutations identified 77% of cases that failed to achieve EFS24. One gene (SLC22A16) at 6q21, a doxorubicin transporter, was lost in 54% of EFS24 failures and our findings suggest it functions as a doxorubicin transporter in DLBCL cells.

The expression levels of JunB, JunD and p-c-Jun are positively correlated with tumor cell proliferation in diffuse large B-cell lymphomas

We analyzed the expression of Jun family in relation to CD30 expression, cell proliferation and B-cell differentiation immunophenotypes [Germinal Center and non-Germinal Center] in diffuse large B-cell lymphomas (DLBCL). Expression and high expression of phosphorylated-c-Jun (p-c-Jun), JunB, JunD and CD30 (cut-off scores 20% and 50%, respectively) was found in 18/103, 49/103, 72/101 and 26/102 cases, respectively, and in 6/103, 27/103, 60/101 and 21/102 cases, respectively. The following significant positive correlations were observed: (a) JunB with cyclin A (p = 0.046), cyclin B1 (p = 0.033), cyclin E (p = 0.003), MUM-1 (p = 0.002) and CD30 (p < 0.001), (b) JunD with Ki67 (p = 0.002) and cyclin E (p = 0.014), (c) p-c-Jun with CD30 (p = 0.015), and (d) high p-c-Jun with cyclin A (p = 0.034). The positive correlation between expression of JunB, JunD and p-c-Jun and tumor cell proliferation in DLBCL, suggests that increased JunB, JunD and p-c-Jun expression may be involved in the pathogenesis of DLBCL by increasing tumor cell proliferation.

Constitutive NF- κ B Activation Underlines Major Mechanism of Drug Resistance in Relapsed Refractory Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of B cell non-Hodgkin's lymphoma (NHL), encompassing 30-40% of the estimated 70,000 cases of NHL in 2014 in the USA. Despite major improvements with immune-chemotherapy, the fraction of patients who still succumb to a refractory or relapsed disease remains high. This review addresses whether the better understanding of the biology of DLBCL defines new therapeutic avenues that may overcome the emerging resistance of this disease to traditional immune-chemotherapy, such as rituximab in combination with traditional chemotherapy agents. Emerging targeted therapy for relapsed refractory DLBCL encompasses more complex molecular abnormalities involving signaling pathways other than NF-κB as mechanism of resistance to immune-chemotherapy. Our review suggests that NF-κB pathway is an important crossroad where other pathways converge as phenotype of resistance that emerges in patients who fail frontline and salvage immune-chemotherapy. Future efforts should aim at targeting the role of NF-κB resistance in clinical trials, where novel agents like lenalidomide and proteasome inhibitors with established activity in this perspective will be an important component in combination therapy, along with new monoclonal antibody, BTK-inhibitors, and other novel therapy agents.

Accurate Classification of Germinal Center B-Cell-Like/Activated B-Cell-Like Diffuse Large B-Cell Lymphoma Using a Simple and Rapid Reverse Transcriptase-Multiplex Ligation-Dependent Probe Amplification Assay: A CALYM Study

Diffuse large B-cell lymphoma, the most common non-Hodgkin lymphoma, is subdivided into germinal center B-cell-like and activated B-cell-like subtypes. Unfortunately, these lymphomas are difficult to differentiate in routine diagnosis, impeding the development of treatments. Patients with these lymphomas can benefit from specific therapies. We therefore developed a simple and rapid classifier based on a reverse transcriptase multiplex ligation-dependent probe amplification assay and 14 gene signatures. Compared with the Affymetrix U133+2 gold standard, all 46 samples (95% CI, 92%-100%) of a validation cohort classified by both techniques were attributed to the expected subtype. Similarly, 93% of the 55 samples (95% CI, 82%-98%) of a second independent series characterized with a mid-throughput gene expression profiling method were classified correctly. Unclassifiable sample proportions reached 13.2% and 13.8% in these cohorts, comparable with the frequency originally reported. The developed assay was also sensitive enough to obtain reliable results from formalin-fixed, paraffin-embedded samples and flexible enough to include prognostic factors such as MYC/BCL2 co-expression. Finally, in a series of 135 patients, both overall (P = 0.01) and progression-free (P = 0.004) survival differences between the two subtypes were confirmed. Because the multiplex ligation-dependent probe amplification method is already in use and requires only common instruments and reagents, it could easily be applied to clinical trial patient stratification to help in treatment decisions.

Cell-secreted signals shape lymphoma identity

Sequencing data show that both specific genes and a number of signaling pathways are recurrently mutated in various types of lymphoma. DNA sequencing analyses of lymphoma have identified several aberrations that might affect the interaction between malignant cells and the tumor microenvironment. Microenvironmental functions are essential to lymphoma; they provide survival and proliferation signals and license immune evasion. It is plausible that interventions that aim to destroy tumor-microenvironment interactions may improve responses to therapeutics. Accordingly, the identification of extrinsic factors and their downstream intracellular signaling targets has led to much progress in understanding tumor-microenvironment interactions. Lymphoma cells are differently influenced by cells' interactions with components of their microenvironment; these cell extrinsic factors include soluble and immobilized factors, the extracellular matrix, and signals presented by neighboring cells. Soluble factors, which are often cell-secreted autocrine and paracrine factors, comprise a significant fraction of targetable molecules. To begin to understand how intercellular communication is conducted in lymphoma, a first order of study is deciphering the soluble factors secreted by malignant cells and microenvironmental cells. These soluble factors are shed into the interstitial fluid in lymphoma and can be conveniently explored using mass spectrometry. Protein components can be detected and quantified, thus enabling the routine navigation of the soluble part of the microenvironment. Elucidating functional and signaling states affords a new paradigm for understanding cancer biology and devising new therapies. This review summarizes knowledge in this field and discusses the utility of studying tumor-secreted factors.

Novel targeted therapies in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin's lymphoma. Next-generation sequencing techniques have improved our understanding of the molecular pathways that may drive oncogenesis. Many novel classes of drugs are in development that may improve the treatment of DLBCL, either as single agents or in combination, that exploit their synergy to overcome resistance. We review the key novel targets and therapeutics in the treatment of DLBCL, including immunomodulatory agents and immunotherapy.

Inhibition of ZEB1 by miR-200 characterizes Helicobacter pylori-positive gastric diffuse large B-cell lymphoma with a less aggressive behavior

Primary gastric diffuse large B-cell lymphomas may or may not have a concurrent component of mucosa-associated lymphoid tissue lymphoma. Diffuse large B-cell lymphoma/mucosa-associated lymphoid tissue lymphomas are often associated with Helicobacter pylori (H. pylori) infection, suggesting that the large cells are transformed from mucosa-associated lymphoid tissue lymphomas. In contrast, only limited data are available on the clinical and molecular features of pure gastric diffuse large B-cell lymphomas. In 102 pure gastric diffuse large B-cell lymphomas, we found H. pylori infection in 53% of the cases. H. pylori-positive gastric diffuse large B-cell lymphomas were more likely to present at an earlier stage (73% vs 52% at stage I/II, P=0.03), to achieve complete remission (75% vs 43%, P=0.001), and had a better 5-year disease-free survival rate (73% vs 29%, P<0.001) than H. pylori-negative gastric diffuse large B-cell lymphomas. Through genome-wide expression profiles of both miRNAs and mRNAs in nine H. pylori-positive and nine H. pylori-negative gastric diffuse large B-cell lymphomas, we identified inhibition of ZEB1 (zinc-finger E-box-binding homeobox 1) by miR-200 in H. pylori-positive gastric diffuse large B-cell lymphomas. ZEB1, a transcription factor for marginal zone B cells, can suppress BCL6, the master transcription factor for germinal center B cells. In 30 H. pylori-positive and 30 H. pylori-negative gastric diffuse large B-cell lymphomas, we confirmed that H. pylori-positive gastric diffuse large B-cell lymphomas had higher levels of miR-200 by qRT-PCR, and lower levels of ZEB1 and higher levels of BCL6 using immunohistochemistry. As BCL6 is a known predictor of a better prognosis in gastric diffuse large B-cell lymphomas, our data demonstrate that inhibition of ZEB1 by miR-200, with secondary increase in BCL6, is a molecular event that characterizes H. pylori-positive gastric diffuse large B-cell lymphomas with a less aggressive behavior.

Diffuse large B cell lymphoma: using pathologic and molecular biomarkers to define subgroups for novel therapy

Diffuse large B cell lymphoma (DLBCL) comprises specific subtypes, disease entities, and other not otherwise specified (NOS) lymphomas. This review will focus on DLBCL NOS because of their prevalence and their heterogeneity with respect to morphology, clinical presentation, biology, and response to treatment. Gene expression profiling of DLBCL NOS has identified molecular subgroups that correlate with prognosis and may have relevance for treatment based on signaling pathways. New technologies have revealed that the "activated B cell" subgroup is linked to activation of the nuclear factor kB (NF-kB) pathway, with mutations found in CD79A/B, CARD11, and MYD88, and loss of function mutations in TNFAIP3. The "germinal center B cell-like" subgroup is linked to mutational changes in EZH2 and CREBBP. Biomarkers that are related to pathways promoting tumor cell growth and survival in DLBCL have been recognized, although their predictive role requires clinical validation. Immunohistochemistry for detecting the expression of these biomarkers is a practical technique that could provide a rational for clinical trial design.

Diffuse large B-cell lymphoma of the sinonasal tract: analysis of survival in 852 cases

PURPOSE

Diffuse large B-cell lymphomas (DLBCLs) are rare tumors of the head and neck that often have non-specific presentations and significant morbidity and mortality. In this analysis we use a large cohort to compare the demographic and disease-specific parameters affecting survival and incidence of DLBCLs.

METHODS

The United States National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registry was utilized to extract data regarding sinonasal diffuse large B-cell lymphoma between 1973 and 2009. A total of 852 cases of sinonasal DLBCLs were found. Presenting symptoms, demographics, disease specific survival, relative survival and survival by treatment modality were described for this rare tumor.

RESULTS

Overall disease specific survival (DSS) at 1-year was 84.7% and at 5 years was 68.0%. DSS was significantly lower for those not treated with radiation therapy, with 1- and 5-year survival rates of 77.3% and 62.5%, versus those treated with radiation therapy, with 1- and 5-year rates of 89.2% and 71.5% (p<0.05). Prognosis was significantly better for patients treated with radiation therapy (HR 0.6, p<0.05) while it was poorer for patients with involvement of multiple sinuses (HR 1.5, 1.8, p<0.05).

CONCLUSIONS

DLBCLs of the sinonasal tract are rare tumors of the head and neck. Survival is significantly improved for those treated with radiation therapy while the involvement of multiple sinuses is a negative prognostic indicator.

Relapsed and refractory aggressive NHL: time for a change

Despite improvements in treatment for aggressive non-Hodgkin lymphoma (NHL), the outcomes for patients with relapsed or refractory B- or T-cell NHL after primary therapy remain poor. While some patients may be cured by the standard of care of salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT), this treatment is unsuitable for the majority. Advances in disease biology and novel therapies have created uncertainty as to the role of old standards and opportunities to develop new rationally developed treatment options. We will review the standard approaches in this disease area and highlight areas that merit further study.