Cell-of-origin determined by both gene expression profiling and immunohistochemistry is the strongest predictor of survival in patients with diffuse large B-cell lymphoma

Nomogram for predicting survival of patients with diffuse large B-cell lymphoma

The international prognostic index (IPI) system has been widely used to predict prognosis in diffuse large B-cell lymphoma (DLBCL). However, this system categorizes DLBCL patients into four risk groups, and cannot optimize individualized prognosis. In addition, other clinicopathological factors, such as molecular aberrations, are not incorporated into the system. To partly overcome these weak points, we developed nomograms to predict individual patient survival. We also incorporated MYD88L265P and CD79BY196 mutations into the nomograms since these mutations are associated with a worse prognosis and their signaling pathways have been highlighted as a therapeutic target. We analyzed 302 DLBCL cases for which multivariate analysis by Cox proportional hazard regression was performed. Nomograms for progression-free survival (PFS) and overall survival (OS) were constructed and assessed by a concordance index (C-index). The nomograms were also evaluated using an open external dataset (n = 187). The MYD88L265P and/or CD79BY196 (MYD88/CD79B) mutation was detected in 62/302 patients. The nomograms incorporating IPI factors exhibited a C-index of 0.738 for PFS and a C-index of 0.765 for OS. The nomograms incorporating IPI factors and the MYD88/CD79B mutation showed a C-index of 0.745 for PFS and a C-index of 0.769 for OS. The nomograms we created were evaluated using an external dataset and were well validated. The present nomograms incorporating IPI factors and the MYD88/CD79B mutation have sufficient discrimination ability, and may effectively predict prognosis in DLBCL patients. The prognostic models we have presented here may help clinicians personalize prognostic assessments and clinical decisions.

Semimethylation is a feature of diffuse large B-cell lymphoma, and subgroups with poor prognosis are characterized by global hypomethylation and short telomere length

BACKGROUND

Large B-cell lymphoma (LBCL) is the most common lymphoma and is known to be a biologically heterogeneous disease regarding genetic, phenotypic, and clinical features. Although the prognosis is good, one-third has a primary refractory or relapsing disease which underscores the importance of developing predictive biological markers capable of identifying high- and low-risk patients. DNA methylation (DNAm) and telomere maintenance alterations are hallmarks of cancer and aging. Both these alterations may contribute to the heterogeneity of the disease, and potentially influence the prognosis of LBCL.

RESULTS

We studied the DNAm profiles (Infinium MethylationEPIC BeadChip) and relative telomere lengths (RTL) with qPCR of 93 LBCL cases: Diffuse large B-cell lymphoma not otherwise specified (DLBCL, n = 66), High-grade B-cell lymphoma (n = 7), Primary CNS lymphoma (n = 8), and transformation of indolent B-cell lymphoma (n = 12). There was a substantial methylation heterogeneity in DLBCL and other LBCL entities compared to normal cells and other B-cell neoplasms. LBCL cases had a particularly aberrant semimethylated pattern (0.15 ≤ β ≤ 0.8) with large intertumor variation and overall low hypermethylation (β > 0.8). DNAm patterns could not be used to distinguish between germinal center B-cell-like (GC) and non-GC DLBCL cases. In cases treated with R-CHOP-like regimens, a high percentage of global hypomethylation (β < 0.15) was in multivariable analysis associated with worse disease-specific survival (DSS) (HR 6.920, 95% CI 1.499-31.943) and progression-free survival (PFS) (HR 4.923, 95% CI 1.286-18.849) in DLBCL and with worse DSS (HR 5.147, 95% CI 1.239-21.388) in LBCL. These cases with a high percentage of global hypomethylation also had a higher degree of CpG island methylation, including islands in promoter-associated regions, than the cases with less hypomethylation. Additionally, telomere length was heterogenous in LBCL, with a subset of the DLBCL-GC cases accounting for the longest RTL. Short RTL was independently associated with worse DSS (HR 6.011, 95% CI 1.319-27.397) and PFS (HR 4.689, 95% CI 1.102-19.963) in LBCL treated with R-CHOP-like regimens.

CONCLUSION

We hypothesize that subclones with high global hypomethylation and hypermethylated CpG islands could have advantages in tumor progression, e.g. by inactivating tumor suppressor genes or promoting treatment resistance. Our findings suggest that cases with high global hypomethylation and thus poor prognosis could be candidates for alternative treatment regimens including hypomethylating drugs.

2024 Update: Advances in the risk stratification and management of large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying clinical outcomes. Our understanding of its molecular makeup continues to improve risk stratification, and artificial-intelligence and ctDNA-based analyses have the potential to enhance risk assessment and disease monitoring. R-CHOP and Pola-R-CHP are used in the frontline setting; chimeric antigen receptor therapy (CART) is now the new standard-of-care for most with primary refractory disease; both CART and autologous stem cell transplantation are utilized in the relapsed and refractory setting. In this review, we summarize the classification and management of DLBCL with an emphasis on recent advances in the field.

Clinico-Pathological, Cytogenetic and Molecular Profiles of Primary Cutaneous Diffuse Large B-Cell Lymphomas

We analyzed the clinico-pathological, cytogenetic and molecular features of 18 Primary Cutaneous Diffuse Large B-Cell Lymphoma (PCDLBCL), and 15 DLBCL secondarily localized to the skin (SCDLBCL), highlighting biologic similarities and differences between the two groups. PCDLBCL were sub classified after histopathological review as PCDLBCL-Leg type (PCDLBCL-LT, 10 cases) and the PCDLBCL-not otherwise specified (PCDLBCL, NOS, 8 cases). Immunohistochemistry for Hans' algorithm markers, BCL2, and MYC was performed. The molecular study included the determination of the cell of origin (COO) by Lymph2Cx assay on Nano string platform, FISH analysis of IgH, BCL2, BCL6, and MYC genes, as well as the mutation analysis of MYD88 gene. At immunohistochemistry, BCL2 and MYC hyper expression was more frequent in LT than in NOS cases and, according to Hans' algorithm, PCDLBCL LT were mostly of the non-GC type (8/10), whereas in PCDLBCL NOS the GC type prevailed (6/8). The determination of COO using Lymph2Cx supported and further confirmed these results. At FISH analysis, all but one LT cases versus 5 out of 8 PCDLBCL NOS showed at least one gene rearrangement among IgH, BCL2, MYC or BCL6. In addition, MYD88 mutations were more frequently present in LT than in NOS subtypes. Interestingly, MYD88- mutated patients were older, with a non-GC phenotype and had worse OS, compared to MYD88 WT cases. Overall, SCDLBCL did not show, at the genetic and expression level, different profiles than PCDLBCL, even if they bear a significantly worse prognosis. At survival analysis, the most important prognostic factors in PCDLBCL patients were age and MYD88 mutation, whereas relapse and high Ki67 expression were relevant in SCDLBCL patients. Our study comprehensively analyzed the clinico-pathological and molecular features of PCDLBCL LT, PCDLBCL-NOS, and SCDLBCL, underlining the differnces among them and the importance of properly identifying these entities at the time of diagnosis.

Cell-of-Origin Targeted Drug Repurposing for Triple-Negative and Inflammatory Breast Carcinoma with HDAC and HSP90 Inhibitors Combined with Niclosamide

We recently identified a cell-of-origin-specific mRNA signature associated with metastasis and poor outcome in triple-negative carcinoma (TNBC). This TNBC cell-of-origin signature is associated with the over-expression of histone deacetylases and zinc finger protein HDAC1, HDAC7, and ZNF92, respectively. Based on this signature, we discovered that the combination of three drugs (an HDAC inhibitor, an anti-helminthic Niclosamide, and an antibiotic Tanespimycin that inhibits HSP90) synergistically reduces the proliferation of the twelve tested TNBC cell lines. Additionally, we discovered that four out of five inflammatory breast carcinoma cell lines are sensitive to this combination. Significantly, the concentration of the drugs that are used in these experiments are within or below clinically achievable dose, and the synergistic activity only emerged when all three drugs were combined. Our results suggest that HDAC and HSP90 inhibitors combined with the tapeworm drug Niclosamide can achieve remarkably synergistic inhibition of TNBC and IBC. Since Niclosamide, HDAC, and HSP90 inhibitors were approved for clinical use for other cancer types, it may be possible to repurpose their combination for TNBC and IBC.

The path towards consensus genome classification of diffuse large B-cell lymphoma for use in clinical practice

Diffuse large B-cell lymphoma (DLBCL) is a widely heterogeneous disease in presentation, treatment response and outcome that results from a broad biological heterogeneity. Various stratification approaches have been proposed over time but failed to sufficiently capture the heterogeneous biology and behavior of the disease in a clinically relevant manner. The most recent DNA-based genomic subtyping studies are a major step forward by offering a level of refinement that could serve as a basis for exploration of personalized and targeted treatment for the years to come. To enable consistent trial designs and allow meaningful comparisons between studies, harmonization of the currently available knowledge into a single genomic classification widely applicable in daily practice is pivotal. In this review, we investigate potential avenues for harmonization of the presently available genomic subtypes of DLBCL inspired by consensus molecular classifications achieved for other malignancies. Finally, suggestions for laboratory techniques and infrastructure required for successful clinical implementation are described.

ZNF92, an unexplored transcription factor with remarkably distinct breast cancer over-expression associated with prognosis and cell-of-origin

Tumor phenotype is shaped both by transforming genomic alterations and the normal cell-of-origin. We identified a cell-of-origin associated prognostic gene expression signature, ET-9, that correlates with remarkably shorter overall and relapse free breast cancer survival, 8.7 and 6.2 years respectively. The genes associated with the ET-9 signature are regulated by histone deacetylase 7 (HDAC7) partly through ZNF92, a previously unexplored transcription factor with a single PubMed citation since its cloning in 1990s. Remarkably, ZNF92 is distinctively over-expressed in breast cancer compared to other tumor types, on a par with the breast cancer specificity of the estrogen receptor. Importantly, ET-9 signature appears to be independent of proliferation, and correlates with outcome in lymph-node positive, HER2+, post-chemotherapy and triple-negative breast cancers. These features distinguish ET-9 from existing breast cancer prognostic signatures that are generally related to proliferation and correlate with outcome in lymph-node negative, ER-positive, HER2-negative breast cancers. Our results suggest that ET-9 could be also utilized as a predictive signature to select patients for HDAC inhibitor treatment.

Clinicopathologic Features and Genomic Signature of De Novo CD5+ Diffuse Large B-Cell Lymphoma: A Multicenter Collaborative Study

De novo CD5+ diffuse large B-cell lymphoma (DLBCL) has poor survival in the era of immunochemotherapy. Accurate gene-based typing and prognostic stratification can enhance the development of effective individualized treatments. Therefore, we conducted a multicenter retrospective study to evaluate the clinicopathologic characteristics, genomic profiles, and prognostic parameters of 61 patients with CD5+ DLBCL and 60 patients with CD5- DLBCL, with the goal of facilitating accurate prognostic stratification and potential individualized treatment strategies. Compared with patients with CD5- DLBCL, older age, advanced stage, higher incidence of central nervous system involvement, and MYC/BCL-2 and p53 overexpression were more prevalent in CD5+ DLBCL. Most patients with CD5+ DLBCL had lymph nodes with non-germinal center B-cell-like or activated B-cell-like subtype according to immunohistochemistry or Lymph2Cx assay. Next-generation sequencing showed that the proportion of MCD subtype (based on the co-occurrence of MYD88 and CD79B mutations) in the CD5+ DLBCL cohort was higher than that in the CD5- DLBCL cohort (54.2% vs. 13.0%, P=0.005). Compared with the CD5- cohort, CD5+ DLBCL patients showed poor 5-year overall survival (70.9% vs. 39.0%, P<0.001). Kaplan-Meier survival analysis indicated that cell of origin, MYC/BCL-2, p53, and BCL-6 expression did not have a prognostic impact on patients with CD5+ DLBCL. Multivariate analysis showed that age above 76 years, advanced stage, higher incidence of central nervous system involvement, and hypoalbuminemia were independent factors for poor prognosis in CD5+ DLBCL patients. In summary, CD5+ DLBCL displays poor prognosis, distinctive clinicopathologic characteristics and predominant genetic features of activated B-cell-like and MCD subtypes with worse survival outcome.

Molecular subtyping of CD5+ diffuse large B-cell lymphoma based on DNA-targeted sequencing and Lymph2Cx

Background

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) showed poor prognosis in the rituximab era, with limited research on its genetic characteristics and cell of origin (COO). We aimed to demonstrate the molecular characteristics of CD5+ DLBCL and to discover potential prognostic factors.

Methods

We included 24 cases of CD5+ DLBCL and 23 CD5-negative (CD5-) counterparts and collected their clinicopathological features. Targeted DNA sequencing of 475 lymphoma-related genes was performed, and all cases were assigned to distinct genetic subtypes using the LymphGen tool. The COO was determined by the Lymph2Cx assay. The Kaplan–Meier method and Cox proportional hazards model were applied to identify the possible prognostic factors.

Results

Compared with their CD5- counterparts, patients with CD5+ DLBCL tended to have a worse prognosis and a higher incidence of MYD88L265P and CD79B double mutation (MCD) subtype (54.17%, P = 0.005) and activated B cell-like (ABC) subtype (62.5%, P = 00017), as determined by next-generation sequencing and Lymph2Cx, respectively. Moreover, PIM1, MYD88, and KMT2D mutations were detected more frequently in CD5+ DLBCL cases (P &lt; 0.05). According to multivariate analysis, MYC/BCL2 double expression and ABC subtype were correlated with unfavorable overall survival (OS). High mRNA expression of SERPINA9 and MME showed a significant correlation with a better OS, and high expression of MME showed a significant correlation with better progression-free survival in CD5+ DLBCL.

Conclusion

The genetic profile of CD5+ DLBCL is characterized by PIM1, MYD88, and KMT2D mutations, with a higher incidence of MCD and ABC subtypes. MYC/BCL2 double expression, ABC subtype, and mRNA expression of SERPINA9 and MME are independently predictive of the prognosis of CD5+ DLBCL.

An integrated prognostic model for diffuse large B‐cell lymphoma treated with immunochemotherapy

Diffuse large B‐cell lymphoma (DLBCL), the most frequent non‐Hodgkin's lymphoma subtype, is characterized by strong biological, morphological, and clinical heterogeneity, but patients are treated with immunochemotherapy in a relatively homogeneous way. Here, we have used a customized NanoString platform to analyze a series of 197 homogeneously treated DLBCL cases. The platform includes the most relevant genes or signatures known to be useful for predicting response to R‐CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone) in DLBCL cases. We generated a risk score that combines the International Prognostic Index with cell of origin and double expression of MYC/BCL2, and stratified the series into three groups, yielding hazard ratios from 0.15 to 5.49 for overall survival, and from 0.17 to 5.04 for progression‐free survival. Group differences were highly significant (p < 0.0001), and the scoring system was applicable to younger patients (<60 years of age) and patients with advanced or localized stages of the disease. Results were validated in an independent dataset from 166 DLBCL patients treated in two distinct clinical trials. This risk score combines clinical and biological data in a model that can be used to integrate biological variables into the prognostic models for DLBCL cases.

Routine application of the Lymph2Cx assay for the subclassification of aggressive B-cell lymphoma: report of a prospective real-world series

The subclassification of diffuse large B-cell lymphoma (DLBCL) into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes has become mandatory in the 2017 update of the WHO classification of lymphoid neoplasms and will continue to be used in the WHO 5^th edition. The RNA-based Lymph2Cx assay has been validated as a reliable surrogate of high-throughput gene expression profiling assays for distinguishing between GCB and ABC DLBCL and provides reliable results from formalin-fixed, paraffin-embedded (FFPE) material. This test has been previously used in clinical trials, but experience from real-world routine application is rare. We routinely applied the Lymph2Cx assay to day-to-day diagnostics on a series of 147 aggressive B-cell lymphoma cases and correlated our results with the immunohistochemical subclassification using the Hans algorithm and fluorescence in situ hybridization findings using break-apart probes for MYC, BCL2, and BCL6. The routine use of the Lymph2Cx assay had a high technical success rate (94.6%) with a low rate of failure due to poor material and/or RNA quality. The Lymph2Cx assay was discordant with the Hans algorithm in 18% (23 of 128 cases). Discordant cases were mainly classified as GCB by the Hans algorithm and as ABC by Lymph2Cx (n = 11, 8.6%). Only 5 cases (3.9%) were classified as non-GCB by the Hans algorithm and as GCB by Lymph2Cx. Additionally, 5.5% of cases (n = 7) were left unclassified by Lymph2Cx, whereas they were defined as GCB (n = 4) or non-GCB (n = 3) by the Hans algorithm. Our data support the routine applicability of the Lymph2Cx assay.

Dysregulated MDR1 by PRDM1/Blimp1 Is Involved in the Doxorubicin Resistance of Non-Germinal Center B-Cell-Like Diffuse Large B-Cell Lymphoma

INTRODUCTION

The chemoresistance mechanism of diffuse large B-cell lymphoma (DLBCL) is still poorly understood, and patient prognosis remains unsatisfactory. This study aimed to investigate drug resistance mechanisms in non-germinal center B-cell-like (non-GCB) DLBCL.

METHODS

Doxorubicin (DOX)-resistant OCI-Ly3 cells were generated through long-term incubation of cells in a medium with gradually increasing DOX concentrations. The expression levels of genes related to drug metabolism were determined using a functional gene grouping polymerase chain reaction (PCR) array. Drug-resistant proteins were identified using bioinformatics, and molecular association networks were subsequently generated. The association and mechanism of key genes were determined using a dual-luciferase reporter assay System and chromatin immunoprecipitation (ChIP). The expression of drug-resistant genes and target genes was then measured using Western blotting and immunohistochemistry. The correlation between gene expressions was analyzed using Spearman's rank correlation coefficient.

RESULTS

Using the PCR array, MDR1 was identified as the key gene that regulates DOX resistance in OCI-Ly3/DOX-A100, a non-GCB DLBCL cell line. The dual-luciferase reporter assay system demonstrated that MDR1 transcription could be inhibited by PRDM1. ChIP results showed that PRDM1 had the ability to bind to the promoter region (-1,132 to -996) of MDR1. In OCI-Ly3/DOX cells, NF-κB activity and PRDM1 expression decreased with an increase in drug-resistant index, whereas MDR1 expression increased with enhanced drug resistance. Immunohistochemical analysis revealed that relative MDR1 expression was higher than that of PRDM1 in human DLBCL tissue samples. A negative correlation was observed between MDR1 and PRDM1.

CONCLUSION

In non-GCB DLBCL cells, NF-κB downregulates PRDM1 and thereby promotes MDR1 transcription by terminating PRDM1-induced transcriptional inhibition of MDR1. Such a mechanism may explain the reason for disease recurrence in non-GCB DLBCL after R-CHOP or combined CHOP with bortezomib treatment. Our findings may provide a potential therapeutic strategy for reducing drug resistance in patients with DLBCL.

Transcriptome sequencing of archived lymphoma specimens is feasible and clinically relevant using exome capture technology

Formalin-fixed, paraffin-embedded (FFPE) specimens are an underutilized resource in medical research, particularly in the setting of transcriptome sequencing, as RNA from these samples is often degraded. We took advantage of an exome capture-based RNA-sequencing protocol to explore global gene expression in paired fresh-frozen (FF) and FFPE samples from 16 diffuse large B-cell lymphoma (DLBCL) patients. While FFPE samples generated fewer mapped reads compared to their FF counterparts, these reads captured the same library complexity and had a similar number of genes expressed on average. Furthermore, gene expression demonstrated a high correlation when comparing housekeeping genes only or across the entire transcriptome (r = 0.99 for both comparisons). Differences in gene expression were primarily seen in lowly expressed genes and genes with small or large coding sequences. Using cell-of-origin classifiers and clinically relevant gene expression signatures for DLBCL, FF, and FFPE samples from the same biopsy paired nearly perfectly in clustering analysis. This was further confirmed in a validation cohort of 50 FFPE DLBCL samples. In summary, we found the biological differences between tumors to be far greater than artifacts created as a result of degraded RNA. We conclude that exome capture transcriptome sequencing data from archival samples can confidently be used for cell-of-origin classification of DLBCL samples.

Factors affecting survival in elderly patients with diffuse large B-Cell lymphoma

INTRODUCTION

Diffuse large B cell lymphoma (DLBCL) has an increasing incidence in elderly patients with poorer prognosis than in younger patients. Clinicians should clearly identify the characteristics and prognostic factors of elderly patients. We analyzed the outcome of elderly DLBCL patients, especially factors affecting survival in real-life clinical practice.

MATERIALS AND METHODS

The data of 330 DLBCL patients at our center were retrospectively evaluated by dividing three groups; younger than 65 years, between 65-79 years, and 80 years and older. We examined the factors affecting survival in DLBCL patients ≥ 65 years old.

RESULTS

The median age of the patients was 61 years (range 16-87). 192 (58.2 %) of our patients were younger than 65 years old, 112 (33.9 %) were between 65-79 years, and 26 (7.9 %) patients were 80 years old or older. The median follow-up was 15 (1-120) months. Median PFS was 38 months in the 65-79 years group, ten months in the ≥ 80 years group; meanwhile, median OS was 43 months in the 65-79 years group, 25 months in the ≥80 years group. The number of patients who relapsed within 12 months of the first-line treatment was 69 (35.9 %) in the <65 years group, it was 60 (53.6 %) in 65-79 years group, and 22 (84.6 %) in ≥80 years group (p < 0.001). The median OS was 9 (7.1-10.9) months in DLBCL patients older than 65 years old who relapsed within 12 months. Early relapse, failure to achieve CR after first-line chemotherapy, and high IPI score were associated with poor survival in patients ≥ 65 years old (p:0.001).

CONCLUSION

Advancing age was a poor prognostic factor for survival of DLBCL. Relapsing within the first year, or failure to achieve complete remission were associated with poorer survival of the elderly DLBCL patients. R-CHOP is the standard treatment in DLBCL, and the best responses are obtained regardless of age. Due to difficulty in receiving standard treatments, novel treatment modalities are needed for better outcomes in elderly patients with DLBCL.

Advances in the Pathogenesis of EBV-Associated Diffuse Large B Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma (NHL) in adults. Epstein-Barr virus (EBV) positive DLBCL of the elderly was defined by the World Health Organization (WHO) in 2008, it was restricted only to patients older than 50 years old, and it was attributed to immunesenescence associated with physiological aging. After the description of EBV-associated DLBCL in children and young adults, the WHO redefined the definition, leading to the substitution of the modifier "elderly" with "not otherwise specified" (EBV + DLBCL, NOS) in the updated classification, and it is no more considered provisional. The incidence of EBV + DLBCL, NOS varies around the world, in particular influenced by the percentage of EBV+ cells used as cut-off to define a case as EBV-associated. EBV has effect on the genetic composition of tumor cells, on survival, and at the recruitment of immune cells at the microenvironment. In this review, the role of EBV in the pathogenesis of DLBCL is discussed.

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.

Diffuse Large B-Cell Lymphoma: Recognition of Markers for Targeted Therapy

Diffuse large B-cell lymphomas (DLBCL)s, the most common type of Non-Hodgkin’s Lymphoma, constitute a heterogeneous group of disorders including different disease sites, strikingly diverse molecular features and a profound variability in the clinical behavior. Molecular studies and clinical trials have partially revealed the underlying causes for this variability and have made possible the recognition of some molecular variants susceptible of specific therapeutic approaches. The main histogenetic groups include the germinal center, activated B cells, thymic B cells and terminally differentiated B cells, a basic scheme where the large majority of DLBCL cases can be ascribed. The nodal/extranodal origin, specific mutational changes and microenvironment peculiarities provide additional layers of complexity. Here, we summarize the status of the knowledge and make some specific proposals for addressing the future development of targeted therapy for DLBC cases.

A refined cell-of-origin classifier with targeted NGS and artificial intelligence shows robust predictive value in DLBCL

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity of B-cell lymphoma. Cell-of-origin (COO) classification of DLBCL is required in routine practice by the World Health Organization classification for biological and therapeutic insights. Genetic subtypes uncovered recently are based on distinct genetic alterations in DLBCL, which are different from the COO subtypes defined by gene expression signatures of normal B cells retained in DLBCL. We hypothesize that classifiers incorporating both genome-wide gene-expression and pathogenetic variables can improve the therapeutic significance of DLBCL classification. To develop such refined classifiers, we performed targeted RNA sequencing (RNA-Seq) with a commercially available next-generation sequencing (NGS) platform in a large cohort of 418 DLBCLs. Genetic and transcriptional data obtained by RNA-Seq in a single run were explored by state-of-the-art artificial intelligence (AI) to develop a NGS-COO classifier for COO assignment and NGS survival models for clinical outcome prediction. The NGS-COO model built through applying AI in the training set was robust, showing high concordance with COO classification by either Affymetrix GeneChip microarray or the NanoString Lymph2Cx assay in 2 validation sets. Although the NGS-COO model was not trained for clinical outcome, the activated B-cell-like compared with the germinal-center B-cell-like subtype had significantly poorer survival. The NGS survival models stratified 30% high-risk patients in the validation set with poor survival as in the training set. These results demonstrate that targeted RNA-Seq coupled with AI deep learning techniques provides reproducible, efficient, and affordable assays for clinical application. The clinical grade assays and NGS models integrating both genetic and transcriptional factors developed in this study may eventually support precision medicine in DLBCL.

Ibrutinib combined with venetoclax for the treatment of relapsed/refractory diffuse large B cell lymphoma

Treatment outcomes of relapsed/refractory diffuse large B cell lymphoma (R/R DLBCL) are far from satisfactory. Certain efficacy of ibrutinib has been observed in non-GCB subtype DLBCL patients. This study aimed to investigate the efficacy and safety of ibrutinib plus BCL2 inhibitor venetoclax in R/R DLBCL patients with non-GCB subtype and BCL2 overexpression. Combinational therapy (ibrutinib 560mg/day; venetoclax started 1 week later, oral dose increased from 100 to 400mg/day in 3 weeks) was conducted, and one cycle was 4 weeks. Both drugs were stopped when disease progress or serious adverse reactions appear. The primary end-point was overall response rate (ORR) at two cycles. From December 2018 to July 2020, a total of 13 patients were treated with the combined therapy. Among them, eleven (84.6%) patients previously received at least two treatment regimens, eight (61.5%) patients were C-myc and BCL2 double expression. The ORR at two cycles was 61.5%, with 3 (23.1%) patients achieved complete remission (CR) and 5 (38.4%) patients achieved partial remission (PR). The ORR at four cycles and six cycles was 53.8% and 46.2%, respectively. The median duration of response was 11 months (range, 1.5-13.6 months). The median progression-free survival and overall survival were 5.6 months (range, 0.4-15.6) and 11.3 months (range, 2.8-17.2), respectively. The most common adverse event was grade 1/2 neutropenia (53.8%), and nonhematologic toxicities included Grade1/2 diarrhea (46.2%) and elevated liver enzymes (30.8%). Combined therapy of ibrutinib and venetoclax showed promising efficacy and synergistic effects in R/R DLBCL patients with non-GCB subtype and BCL2 overexpression, and the toxicities were well-tolerated.

Characteristics and Management of TP53-Mutated Diffuse Large B-Cell Lymphoma Patients

Background/Aim

TP53 mutation is recognized as a negative prognostic factor for patients with diffuse large B-cell lymphoma (DLBCL). Here, we present the characteristics of TP53^mut DLBCL patients following investigation of the effect of a treatment approach on survival of TP53^mut DLBCL patients.

Methods

A total of 44 DLBCL patients with TP53^mut and treated with an R-CHOP regimen were included for analysis. Patients who failed to achieve a complete response (CR) to initial treatment or relapsed in the first 6 months after initial CR were deemed to have primary refractory disease.

Results

Among 44 patients harboring TP53 mutations who underwent upfront R-CHOP or R-CHOP–like treatment, 21 (47.7%) had limited-stage and 23 (52.3%) presented advanced-stage disease. Apart from the seven patients receiving upfront surgical resection, 37 had measurable disease under the R-CHOP regimen, with 59.1% (n=26) developing primary refractory disease. Seven limited-stage patients after early complete resection and one with residue resection remained event-free at median follow-up of 37 months. Multivariate analysis revealed that elevated baseline lactate dehydrogenase (LDH), extranodal involvement (two or more), Ann Arbor stage, and locoregional treatment (surgery or radiation therapy) were independent indicators for progression-free survival (PFS). After adjustment for baseline LDH and extranodal involvement, adding locoregional treatment including surgery and radiation to the R-CHOP regimen significantly improved PFS (p=0.008) and overall survival (p=0.017) in limited-stage TP53^mut DLBCL patients compared to R-CHOP–only treatment.

Conclusion

This study presents the characteristics of TP53-mutated DLBCL and implies a potential benefit of locoregional treatment in limited-stage DLBCL patients with TP53 mutations.

The expressions of MUM-1 and Bcl-6 in ALK-negative systemic anaplastic large cell lymphoma with skin involvement and primary cutaneous anaplastic large cell lymphoma

BACKGROUND

It is important to differentiate between primary cutaneous anaplastic large cell lymphoma (PC-ALCL) and ALK-negative systemic ALCL with skin involvement, as the prognoses and treatments for these two diseases are considerably different.

OBJECTIVE

This study aimed to compare the expressions of multiple myeloma oncogene 1 (MUM-1) and B-cell lymphoma 6 (Bcl-6) in PC-ALCL and ALK-negative systemic ALCL.

METHODS

This retrospective qualitative study investigated the clinical features of 7 patients with ALK-negative PC-ALCL, 5 patients with ALK-negative systemic ALCL with skin involvement, and 6 patients with ALK-positive systemic ALCL with skin involvement. The MUM-1 and Bcl-6 expressions were evaluated using immunohistochemistry.

RESULTS

The MUM-1 expression rates were 85.7% in the PC-ALCL cases and 100% in the ALK-negative systemic ALCL with skin involvement cases. The Bcl-6 expression rates were 28.5% in the PC-ALCL cases and 20% in the ALK-negative systemic ALCL cases with skin involvement.

CONCLUSION

Although the cutaneous manifestations of ALK-negative systemic ALCL and PC-ALCL are similar, the prognoses and treatment approaches are considerably different. Our results indicate that MUM-1 expression is commonly expressed in both types of ALCL, but Bcl-6 is less commonly expressed in PC-ALCL cases and systemic ALCL with skin involvement cases.

Cell-of-origin determined by both gene expression profiling and immunohistochemistry is the strongest predictor of survival in patients with diffuse large B-cell lymphoma

The tumor cells in diffuse large B‐cell lymphomas (DLBCL) are considered to originate from germinal center derived B‐cells (GCB) or activated B‐cells (ABC). Gene expression profiling (GEP) is preferably used to determine the cell of origin (COO). However, GEP is not widely applied in clinical practice and consequently, several algorithms based on immunohistochemistry (IHC) have been developed. Our aim was to evaluate the concordance of COO assignment between the Lymph2Cx GEP assay and the IHC‐based Hans algorithm, to decide which model is the best survival predictor. Both GEP and IHC were performed in 359 homogenously treated Swedish and Danish DLBCL patients, in a retrospective multicenter cohort. The overall concordance between GEP and IHC algorithm was 72%; GEP classified 85% of cases assigned as GCB by IHC, as GCB, while 58% classified as non‐GCB by IHC, were categorized as ABC by GEP. There were significant survival differences (overall survival and progression‐free survival) if cases were classified by GEP, whereas if cases were categorized by IHC only progression‐free survival differed significantly. Importantly, patients assigned as non‐GCB/ABC both by IHC and GEP had the worst prognosis, which was also significant in multivariate analyses. Double expression of MYC and BCL2 was more common in ABC cases and was associated with a dismal outcome. In conclusion, to determine COO both by IHC and GEP is the strongest outcome predictor to identify DLBCL patients with the worst outcome.

Consecutive Hypoalbuminemia Predicts Inferior Outcome in Patients With Diffuse Large B-Cell Lymphoma

The prognostic value of albumin changes between diagnosis and end-of-treatment (EoT) in diffuse large B-cell lymphoma (DLBCL) remains unknown. We retrospectively analyzed 574 de novo DLBCL patients treated with R-CHOP from our and two other centers. All patients were divided into a training cohort (n = 278) and validation cohort (n = 296) depending on the source of the patients. Overall survival (OS) and progression-free survival (PFS) were analyzed by the method of Kaplan-Meier and Cox proportional hazard regression model. In the training cohort, 163 (58.6%) patients had low serum albumin at diagnosis, and 80 of them were present with consecutive hypoalbuminemia at EoT. Patients with consecutive hypoalbuminemia showed inferior OS and PFS (p = 0.010 and p = 0.079, respectively). Similar survival differences were also observed in the independent validation cohort (p = 0.006 and p = 0.030, respectively). Multivariable analysis revealed that consecutive hypoalbuminemia was an independent prognostic factor OS [relative risk (RR), 2.249; 95% confidence interval (CI), 1.441-3.509, p < 0.001] and PFS (RR, 2.001; 95% CI, 1.443-2.773, p < 0.001) in all DLBCL patients independent of IPI. In conclusion, consecutive hypoalbuminemia is a simple and effective adverse prognostic factor in patients with DLBCL, which reminds us to pay more attention to patients with low serum albumin at EoT during follow-up.