Absence of cyclin-D2 and Bcl-2 expression within the germinal centre type of diffuse large B-cell lymphoma identifies a very good prognostic subgroup of patients

CCND2 mRNA Expression Is Correlated With R-CHOP Treatment Efficacy and Prognosis in Patients With ABC-DLBCL

In this study we investigated whether the expression of cyclin D2 (CCND2) mRNA in activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) was correlated with the efficacy of Rituximab combined with chemotherapy (R-CHOP) treatment and patient prognosis. Tissue microarray and RNAscope in situ hybridization were used to detect CCND2 mRNA expression in 117 ABC-DLBCL tumor tissues and associations between CCND2 expression and progression-free survival was analyzed. We also downloaded data from the Gene Expression Omnibus database to analyze CCND2 expression and the efficacy of R-CHOP treatment and prognosis of patients with newly diagnosed ABC-DLBCL. The positive expression rate of CCND2 mRNA in patients with ABC-DLBCL was 41%. Progression-free survival was significantly lower in patients with positive rather than those negative CCND2 expression (P = 0.005). Further, R-CHOP treatment was significantly more effective for patients with ABC-DLBCL with high CCND2 mRNA expression than those with low expression (P = 0.039). Multivariate regression analysis suggested that high CCND2 expression was an independent prognostic risk factor for progression-free survival for patients with ABC-DLBCL who achieved complete remission after R-CHOP treatment. CCND2 expression in ABC-DLBCL tumors, detected by RNA in situ hybridization, is closely related to the curative effect of R-CHOP and patient prognosis following R-CHOP treatment, and represents a potential biomarker for treatment efficacy and prognostic evaluation in patients with ABC-DLBCL.

Bioinformatic identification and expression analysis of the chicken B cell lymphoma (BCL) gene

BACKGROUND

B cell lymphoma (BCL) families play an important role in apoptosis as a growth factor, cell death programming, cytokine expression and immune-related genes expression.

OBJECTIVES

In this study, to investigate the roles of BCLs, we performed genome-wide identification, expression and functional analyses of the BCL family in chicken.

METHODS

Chicken BCLs genes were identified and analyzed by using bioinformatics approach. Expression profiles and Hierarchical cluster analysis of the BCLs genes in different chicken tissues were obtained from the genome-wide RNA-seq in the GEO, and Cluster and Java Treeview, respectively.

RESULTS

A total of 16 BCLs genes were identified from the chicken genome, which could be further classified into five distinct groups in the phylogenetic tree. On the other hand, the interaction among BCLs proteins and between BCLs proteins with NF-κB subunits are limited, indicating that the remaining the functions of BCLs protein could be investigated in chicken. Moreover, KEGG pathway analysis indicated that BCL gene family was involved in regulation of apoptotic and immune response. Finally, BCL gene family was differentially expressed in chicken tissues, pathogen infection and growth stages of early chicken early embryo.

CONCLUSION

This study provides significant insights into the potential functions of BCLs in chicken, including the regulation of apoptosis, cell death and expression of immune-related genes.

Prognostic significance of cyclin D3 expression in malignancy patients: a meta-analysis

Background

As a pivotal regulator, cyclin D3 gives play to a crucial value in conversion from the G1 stage to the S stage of cell cycle, which is implicated in tumor progression, especially proliferation and migration. Recent literatures have reported that cyclin D3 could predict survival time of malignancy patients. But, its prognostic role of cyclin D3 in neoplasms remains controversial.

Methods

Databases involving EMBASE, PubMed and Web of Science were carefully searched, and literatures investigating the prognostic effect of aberrantly expressing cyclin D3 among human cancers were collected for further analysis. We used both hazards ratios and its corresponding 95% confidence intervals to evaluate the connection among the survival rate of malignancy patients and the expression of cyclin D3.

Results

There were 13 eligible researches involving 16 cohorts and 2395 participants which were included in this study. The outcomes suggested that highly expressing cyclin D3 was significantly correlated with worse clinical prognosis of overall survival (HR 1.88; 95% CI 1.31–2.69) and disease specific survival (HR 2.68; 95% CI 1.35–5.31). But there existed no significant connection between the elevated expression of cyclin D3 with disease free survival (HR 2.65; 95% CI 0.83–8.46), recurrence-free survival (HR 2.86; 95% CI 0.82–9.96) and progression-free survival (HR 5.24; 95% CI 0.46–60.25) of diffident kinds of malignancy patients. Moreover, we discovered that elevated cyclin D3 expression was significantly connected with decreased overall survival in lymphoma (HR 3.72; 95% CI 2.18–6.36) while no significant relevance between highly expressing cyclin D3 and the overall survival in breast cancer was obtained (HR 2.12; 95% CI 0.76–5.91).

Conclusions

This meta-analysis demonstrated that highly expressing cyclin D3 might be an unfavorable prognostic biomarker for various malignancy patients, which can make great contributions to the clinical diagnosis and treatment.

Human bone marrow-derived mesenchymal stem cells promote the growth and drug-resistance of diffuse large B-cell lymphoma by secreting IL-6 and elevating IL-17A levels

Background

The drug-resistance and relapse of diffuse large B-cell lymphoma (DLBCL), which are related to mesenchymal stem cells (MSCs), have become increasingly common. However, the underlying mechanisms remain elusive.

Methods

CCK 8 assay, colony formation assay, and xenograft mouse model were used to investigate the effects of hBMSCs on DLBCL growth. Immunohistochemistry, qRT-PCR, and ELISA were used to study the expressions of IL-6 and IL-17A. Flow cytometry was used to analyze Th17 cells and Treg cells expressions. Western blot analysis, microarray analysis, and bioinformatics analysis were used to analyze the pathways of IL-6 or IL-17A mediated DLBCL growth.

Results

HBMSCs promoted DLBCL growth by secreting IL-6 in vitro and in vivo and simultaneously upregulating IL-17A in vitro. IL-6 and IL-17A synergistically promoted the growth and drug-resistance of DLBCL cells by protecting them from spontaneous or drug-induced apoptosis in vitro. IL-6 or IL-17A activated the JAK2/STAT3 pathway or upregulated cyclin D2 via activation of PI3K/Akt signaling in vitro, respectively.

Conclusions

The present results indicated that hBMSCs might have a “dual effect” on promoting DLBCL progression and drug-resistance by secreting IL-6 and upregulating IL-17A. IL-6, IL-17A, p-STAT3, p-Akt or cyclin D2 may be potential molecular targets for overcoming drug-resistance in patients with relapsed or refractory DLBCL.

Giant solitary primary intracranial lymphoma masquerading as meningioma: a case and review of literature

Non-Hodgkin's lymphomas (NHL) with intracranial origin are very rare and constitutes about 1-2% of primary central nervous system lymphomas (PCNSL). Diffuse large B cell lymphoma (DLBCL) is the most common subtype of NHL and mostly seen in immunocompromised patients. Therefore, the occurrence of giant solitary DLBCL in an immunocompetent patient is puzzling. We present a case of 68-year-old man who was admitted at our facility with a history of “hypomnesia of two (2) months” duration. Magnetic resonance imaging (MRI) revealed a space occupying lesion in the bilateral frontal lobe and corpus callosum measuring about 5.4cm * 4.6cm * 3.8cm with mixed signal intensities and vasogenic edema around the mass. Radiological, this mass was mistaken for meningioma until histopathological studies revealed DLBCL. Giant solitary primary intracranial lymphomas are very rare and can be mistake for meningioma even with very experience radiologist or neurosurgeon since the radiological features of PCNSL can be very unspecific. We achieved to total resection because of the giant and solitary nature of our case. The prognosis of PCNSL is general very poor when the patient is immunocompromised. In immunocompetent patients, who are well managed with surgery and chemotherapy, the overall survival and quality of life can very encouraging.

PROGNOSTIC VALUE OF IMMUNOHISTOCHEMICAL MARKERS IN PATIENTS WITH DIFFUSE LARGE B-CELL LYMPHOMA

Diffuse large B-cell lymphoma (DLBCL) is a potentially curable disease, but standard treatment is not effective enough for all patients. That is why so important to identify high risk patients who need more aggressive therapy at the time of diagnosis. Nowadays prognosis for patients with DLBCL is based on International prognostic index (IPI). However, this index consists of only clinical parameters and does not include the biological characteristics of the tumour. Immunohistochemistry (IHC) markers could also play a prognostic role. There are some publications regarding predictive and prognostic role of expression of Bcl-2, Bcl-6, MUM1, CD10 and CD30, but their results are controversial. The aim of our study was to analyze prognostic role of these markers, to compare survival of patients with positive and negative expression of these markers and to build a prognostic model which include biological parameters for identifying high risk patients. There were statistically significant differences in EFS between the group of patients with negative and positive expression of CD10 (51.5 % versus 72.5 %, р=0.01) and in OS between the group of patients with negative and positive expression of Bcl-6 (61.1 % versus 79.6 %, р=0.03). Six-factors nonlinear neural network prediction model (MLP_6) was built. The sensitivity of the model is 63.2 % (95 % CІ 49.3 % – 75.6 %), specificity – 85.2 % (95 % CІ 79.1 % – 90.1 %). Prognostic factors include negative IHC expression of Bcl-6, CD10, non-GCB molecular subtype (according to algorithm Hans), gender (male), advanced Ann-Arbor stages, >2extranodal involvement. Our nonlinear neural network prediction model could improve prognostic role of IPI by adding of biological tumour characteristics (IHC expression of CD10, Bcl-6, molecular subtype by IHC algorithm).

Expression of D-type cyclins in mantle cell and diffuse large B-cell lymphomas

D-type cyclins are involved in cell cycle regulation and play an important role in the pathogenesis of lymphomas. Aberrant expression of cyclin D1 is associated with mantle cell lymphoma (MCL) and serves as a diagnostic marker of MCL. Analysis of cyclin D expression in tumor tissues of patients with diffuse large B-cell lymphoma (DLBCL) which comprises a heterogeneous group of tumors may contribute to their stratification. We analyzed expression of cyclin D1, D2, and D3 mRNAs in 30 MCL and 104 DLBCL patients using qRT-PCR and addressed their significance for disease outcome. We confirmed a high level of cyclin D1 mRNA in 29 MCL cases (97%). One case (3%) was identified as positive for cyclin D2. Expression of cyclin D1 was limited to MCL and did not occur in DLBCL. Overexpression of cyclin D2, which is rare in MCL, occurred more frequently in DLBCL (11 cases, 10.6%). We showed that high expression of cyclin D2 in DLBCL cases de novo decreased the overall survival rate (P=0.016) and progression-free survival (P=0.009). The expression pattern of cyclin D3 was similar in both types of studied lymphomas and it did not affect the disease outcome.

Large B-cell lymphoma of the base of the tongue and oral cavity: a practical approach to identifying prognostically important subtypes

OBJECTIVE

The aim of this study is to illustrate a practical approach to the identification of prognostically important subtypes of large B-cell lymphomas.

STUDY DESIGN

Twenty-six cases of large B-cell lymphoma in the base of the tongue and oral cavity were retrieved from 2003 through 2012. All cases were classified based on the 2008 World Health Organization criteria. Hematoxylin-eosin-stained sections, immunohistochemical stains, flow cytometric immunophenotypic data, and fluorescence in situ hybridization studies were performed and evaluated.

RESULTS

Four different subtypes of large B-cell lymphoma were identified: pleomorphic variant mantle cell lymphoma, Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly, diffuse large B-cell lymphoma not otherwise specified, and B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma, including a case of double-hit lymphoma.

CONCLUSIONS

Diverse subtypes of large B-cell lymphoma were identified in the base of tongue and oral cavity, and illustrate a practical approach to recognizing prognostically important lymphoma subtypes.

De novo CD5-positive diffuse large B-cell lymphomas show high specificity for cyclin D2 expression

D cyclins positively regulate the cell cycle and mediate the pathogenesis of some lymphomas. Cyclin D1 overexpression is the hallmark of mantle cell lymphoma, whereas cyclins D2 and D3 are reportedly not as specific to certain lymphomas as cyclin D1. In this study, cyclin D2 was found to be overexpressed in 98% of de novo CD5-positive diffuse large B-cell lymphomas (DLBCLs) (50/51) and in 28% of CD5-negative DLBCLs (14/51). A statistically significant difference was observed between these two groups (p<0.0001). In contrast, no statistical difference was found in the cyclin D3 expression between CD5-positive (18/51) and CD5-negative (24/51) DLBCLs (p=0.23). Based on these findings, cyclin D2 is therefore considered to be closely associated with de novo CD5-positive DLBCLs. This insight may be useful for overcoming the inferior survival of this aggressive lymphoma.

MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures: a report from The International DLBCL Rituximab-CHOP Consortium Program

Diffuse large B-cell lymphoma (DLBCL) is stratified into prognostically favorable germinal center B-cell (GCB)-like and unfavorable activated B-cell (ABC)-like subtypes based on gene expression signatures. In this study, we analyzed 893 de novo DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). We show that MYC/BCL2 protein coexpression occurred significantly more commonly in the ABC subtype. Patients with the ABC or GCB subtype of DLBCL had similar prognoses with MYC/BCL2 coexpression and without MYC/BCL2 coexpression. Consistent with the notion that the prognostic difference between the 2 subtypes is attributable to MYC/BCL2 coexpression, there is no difference in gene expression signatures between the 2 subtypes in the absence of MYC/BCL2 coexpression. DLBCL with MYC/BCL2 coexpression demonstrated a signature of marked downregulation of genes encoding extracellular matrix proteins, those involving matrix deposition/remodeling and cell adhesion, and upregulation of proliferation-associated genes. We conclude that MYC/BCL2 coexpression in DLBCL is associated with an aggressive clinical course, is more common in the ABC subtype, and contributes to the overall inferior prognosis of patients with ABC-DLBCL. In conclusion, the data suggest that MYC/BCL2 coexpression, rather than cell-of-origin classification, is a better predictor of prognosis in patients with DLBCL treated with R-CHOP.

Pathophysiology and molecular aspects of diffuse large B-cell lymphoma

Diffuse large B-Cell lymphoma is the most common subtype of non-Hodgkin lymphoma in the West. In Brazil, it is the fifth cause of cancer, with more than 55,000 cases and 26,000 deaths per year. At Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - HCFMUSP, diffuse large B-Cell lymphoma represents 49.7% of all non-Hodgkin lymphoma cases. Initially, the classification of non-Hodgkin lymphoma was based on morphology, but advances in immunology and molecular medicine allowed the introduction of a biological classification for these diseases. As for other cancers, non-Hodgkin lymphoma involves patterns of multifactorial pathogenesis with environmental factors, as well as genetic, occupational and dietary factors, contributing to its development. Multiple lesions involving molecular pathways of B-cell proliferation and differentiation may result in the activation of oncogenes such as the BCL2, BCL6, and MYC genes and the inactivation of tumor suppressor genes such as p53 and INK4, as well as other important transcription factors such as OCT-1 and OCT-2. A dramatic improvement in survival was seen after the recent introduction of the anti-CD20 monoclonal antibody. The association of this antibody to the cyclophosphamide, hydroxydaunorubicin, oncovin and prednisolone (CHOP) regimen has increased overall survival of diffuse large B-Cell lymphoma and follicular lymphoma patients by 20%. However, 50% of all diffuse large B-Cell lymphoma patients remain incurable, creating a demand for more research with new advances in treatment. Thus, it is important to know and understand the key factors and molecular pathways involved in the pathogenesis of diffuse large B-Cell lymphoma.

Comprehensive gene expression profiling and immunohistochemical studies support application of immunophenotypic algorithm for molecular subtype classification in diffuse large B-cell lymphoma: a report from the International DLBCL Rituximab-CHOP Consortium Program Study

Gene expression profiling (GEP) has stratified diffuse large B-cell lymphoma (DLBCL) into molecular subgroups that correspond to different stages of lymphocyte development-namely germinal center B-cell like and activated B-cell like. This classification has prognostic significance, but GEP is expensive and not readily applicable into daily practice, which has lead to immunohistochemical algorithms proposed as a surrogate for GEP analysis. We assembled tissue microarrays from 475 de novo DLBCL patients who were treated with rituximab-CHOP chemotherapy. All cases were successfully profiled by GEP on formalin-fixed, paraffin-embedded tissue samples. Sections were stained with antibodies reactive with CD10, GCET1, FOXP1, MUM1 and BCL6 and cases were classified following a rationale of sequential steps of differentiation of B cells. Cutoffs for each marker were obtained using receiver-operating characteristic curves, obviating the need for any arbitrary method. An algorithm based on the expression of CD10, FOXP1 and BCL6 was developed that had a simpler structure than other recently proposed algorithms and 92.6% concordance with GEP. In multivariate analysis, both the International Prognostic Index and our proposed algorithm were significant independent predictors of progression-free and overall survival. In conclusion, this algorithm effectively predicts prognosis of DLBCL patients matching GEP subgroups in the era of rituximab therapy.

Cellular (FLICE) like inhibitory protein (cFLIP) expression in diffuse large B-cell lymphoma identifies a poor prognostic subset, but fails to predict the molecular subtype

Immunohistochemistry can sub-classify diffuse large B-cell lymphoma (DLBCL) into germinal centre B-cell like (GCB) and non-GCB subtypes. The latter consists predominately of the activated B-cell like subgroup in which nuclear factor kappa-B activation is its characteristic. Expression of cellular caspase 8 (FLICE)-like inhibitory protein (cFLIP), a caspase 8 homologue, is regulated by nuclear factor kappa-B signalling, and it is the main inhibitor of Fas ligand activated apoptosis. To determine if cFLIP expression was confined to non-GCB subtype, we studied 66 cases of DLBCL. cFLIP expression showed no significant correlation to DLBCL subtypes (GCB or non-GCB) but was associated with a worse clinical outcome. For cFLIP positive and negative patients, the five-year event free survival was 20 and 31%, respectively (p = 0.049), and the five-year overall survival was 20 and 57%, respectively (p = 0.041).

Immunoblastic morphology but not the immunohistochemical GCB/nonGCB classifier predicts outcome in diffuse large B-cell lymphoma in the RICOVER-60 trial of the DSHNHL

The survival of diffuse large B-cell lymphoma patients varies considerably, reflecting the molecular diversity of tumors. In view of the controversy whether cytologic features, immunohistochemical markers or gene expression signatures may capture this molecular diversity, we investigated which features provide prognostic information in a prospective trial in the R-CHOP treatment era. Within the cohort of DLBCLs patients treated in the RICOVER-60 trial of the German High-Grade Lymphoma Study Group (DSHNHL), we tested the prognostic impact of IB morphology in 949 patients. The expression of immunohistochemical markers CD5, CD10, BCL2, BCL6, human leukocyte antigen (HLA)–DR, interferon regulatory factor-4/multiple myeloma-1 (IRF4/MUM1), and Ki-67 was assessed in 506 patients. Expression of the immunohistochemical markers tested was of modest, if any, prognostic relevance. Moreover, the Hans algorithm using the expression patterns of CD10, BCL6, and interferon regulatory factor-4/multiple myeloma-1 failed to show prognostic significance in the entire cohort as well as in patient subgroups. IB morphology, however, emerged as a robust, significantly adverse prognostic factor in multivariate analysis, and its diagnosis showed a good reproducibility among expert hematopathologists. We conclude, therefore, that IB morphology in DLBCL is likely to capture some of the adverse molecular alterations that are currently not detectable in a routine diagnostic setting, and that its recognition has significant prognostic power.

Prognostic evaluation of immunohistochemical profiles in diffuse large B-cell lymphoma: a Chinese study

Diffuse large B-cell lymphoma (DLBCL) has been classified into different prognostic subgroups using immunohistochemistry in Western populations. However, the applicability in Chinese patients of these subgroups was unclear. We collected 116 specimens and performed immunohistochemical staining for CD10, BCL-6, MUM1, CD138, and CD5, and the results were classified into subgroups according to 3 different algorithms. We then analyzed the subgroups' correlation to patient survival. Expression of CD10 and BCL-6 predicted favorable 5-year OS (70 and 62.5%, respectively) and PFS (64.3 and 61.5%, respectively) rates. In contrast, the expression of MUM1 predicted unfavorable 5-year OS (23.1%) and PFS (17.9%) rates and was also independent of other markers. All algorithms led to useful subclassifications. Using Hans' algorithm based on CD10, BCL-6, and MUM1, the non-germinal center (GC) subgroup (66.4%) had worse 5-year OS (29.8%) and PFS (26.7%) rates than did the GC subgroup. Likewise, using Muris' algorithm based on CD10 and MUM1, fewer non-GC cases (27%) showed poorer OS (20.3%) and PFS (16.2%) rates than did GC cases, an effect that was independent of both the International Prognostic Index, a clinical indicator, and treatment. It identified a subgroup with a high-risk of death and seemed to be applicable in our series. In conclusion, these algorithms can be used effectively in Chinese patients with DLBCL.

Identification of molecular targets associated with transformed diffuse large B cell lymphoma using highly purified tumor cells

Follicular lymphoma (FL) frequently transforms into the more aggressive diffuse large B cell lymphoma (DLBCL-tr), but no protein biomarkers have been identified for predictive or early diagnosis. Gene expression analyses have identified genes changing on transformation but have failed to be reproducible in different studies, reflecting the heterogeneity within the tumor tissue and between tumor samples. Gene expression analyses on Affymetrix Human Genome U133 Plus 2.0 arrays were performed, using flow cytometry sorted tumor cells derived from FL and transformed DLBCL. To identify molecular targets associated with the transformation, subsequent immunohistochemistry (IHC) analyses of the corresponding proteins were performed. Using highly purified cells, this study identified 163 genes, which were significantly deregulated during the transformation in a majority of cases. Among the upregulated transcripts, 13 genes were selected for validation using IHC, based on the availability of commercial antibodies, and galectin-3 and NEK2 proteins specifically identify DLBCL-tr, when compared with FL. We demonstrate that by purifying tumor cells through cell sorting, thereby reducing the heterogeneity due to infiltrating cells, it was possible to identify distinct differences between tumor entities rather than variations due to cellular composition. Galectin-3 and NEK2 both identified a subgroup of DLBCL-tr, and the function of these protein markers also suggests a biological role in the transformation process.

Immunophenotypic analysis of AIDS-related diffuse large B-cell lymphoma and clinical implications in patients from AIDS Malignancies Consortium clinical trials 010 and 034

PURPOSE

Diffuse large B-cell lymphoma (DLBCL) represents a clinically heterogeneous disease. Models based on immunohistochemistry predict clinical outcome. These include subdivision into germinal center (GC) versus non-GC subtypes; proliferation index (measured by expression of Ki-67), and expression of BCL-2, FOXP1, or B-lymphocyte-induced maturation protein (Blimp-1)/PRDM1. We sought to determine whether immunohistochemical analyses of biopsies from patients with DLBCL having HIV infection are similarly relevant for prognosis.

PATIENTS AND METHODS

We examined 81 DLBCLs from patients with AIDS in AMC010 (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP] v CHOP-rituximab) and AMC034 (etoposide, doxorubicin, vincristine, prednisone, and dose-adjusted cyclophosphamide plus rituximab concurrent v sequential) clinical trials and compared the immunophenotype with survival data, Epstein-Barr virus (EBV) positivity, and CD4 counts.

RESULTS

The GC and non-GC subtypes of DLBCL did not differ significantly with respect to overall survival or CD4 count at cancer presentation. EBV could be found in both subtypes of DLBCL, although less frequently in the GC subtype, and did not affect survival. Expression of FOXP1, Blimp-1/PRDM1, or BCL-2 was not correlated with the outcome in patients with AIDS-related DLBCL.

CONCLUSION

These data indicate that with current treatment strategies for lymphoma and control of HIV infection, commonly used immunohistochemical markers may not be clinically relevant in HIV-infected patients with DLBCL. The only predictive immunohistochemical marker was found to be Ki-67, where a higher proliferation index was associated with better survival, suggesting a better response to therapy in patients whose tumors had higher proliferation rates.

A new immunostain algorithm classifies diffuse large B-cell lymphoma into molecular subtypes with high accuracy

PURPOSE

Hans and coworkers previously developed an immunohistochemical algorithm with approximately 80% concordance with the gene expression profiling (GEP) classification of diffuse large B-cell lymphoma (DLBCL) into the germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes. Since then, new antibodies specific to germinal center B-cells have been developed, which might improve the performance of an immunostain algorithm.

EXPERIMENTAL DESIGN

We studied 84 cases of cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP)-treated DLBCL (47 GCB, 37 ABC) with GCET1, CD10, BCL6, MUM1, FOXP1, BCL2, MTA3, and cyclin D2 immunostains, and compared different combinations of the immunostaining results with the GEP classification. A perturbation analysis was also applied to eliminate the possible effects of interobserver or intraobserver variations. A separate set of 63 DLBCL cases treated with rituximab plus CHOP (37 GCB, 26 ABC) was used to validate the new algorithm.

RESULTS

A new algorithm using GCET1, CD10, BCL6, MUM1, and FOXP1 was derived that closely approximated the GEP classification with 93% concordance. Perturbation analysis indicated that the algorithm was robust within the range of observer variance. The new algorithm predicted 3-year overall survival of the validation set [GCB (87%) versus ABC (44%); P < 0.001], simulating the predictive power of the GEP classification. For a group of seven primary mediastinal large B-cell lymphoma, the new algorithm is a better prognostic classifier (all "GCB") than the Hans' algorithm (two GCB, five non-GCB).

CONCLUSION

Our new algorithm is significantly more accurate than the Hans' algorithm and will facilitate risk stratification of DLBCL patients and future DLBCL research using archival materials.

Prognostic impact of activated B-cell focused classification in diffuse large B-cell lymphoma patients treated with R-CHOP

Gene expression profiling studies initially enabled diffuse large B-cell lymphoma to be divided into germinal center and activated B-cell-like subtypes, which define high- and low-risk patient groups when treated with chemotherapy. Attempts to reproduce the prognostic classification immunohistochemically have, however, provided inconsistent results. The aim of this study was to determine whether modified immunohistochemical classification of cell of origin focusing on activated B-cell-like markers could be used to predict the outcome of immunochemotherapy-treated diffuse large B-cell lymphoma patients. The expression of CD10, Bcl-6, MUM1/IRF4, Bcl-2, and FOXP1 was determined immunohistochemically from 88 samples of diffuse large B-cell lymphoma patients treated uniformly with R-CHOP. When the modified classification using MUM1/IRF4 and FOXP1 positivities as activated B-cell-like markers was applied to distinguish the patients between the activated B-cell-like and other diffuse large B-cell lymphoma subtypes, a significantly worse outcome was seen for the patients with the activated B-cell-like phenotype (3-year failure-free survival 63 vs 82%, P=0.048, overall survival 69 vs 85%, P=0.110). Similarly, according to the Muris algorithm, the group 2 patients representing Bcl-2-positive post-germinal center patients showed an inferior outcome in comparison to the group 1 patients (failure-free survival 59 vs 81%, P=0.041, overall survival 67 vs 82%, P=0.159). In contrast, when the classification of the same cohort was performed according to the Hans algorithm, no significant difference in survival was observed between the germinal center and non-germinal center patients. In conclusion, the data suggest that both the modified activated B-cell-like and Muris classifications define the non-germinal center phenotype as an adverse risk factor in R-CHOP-treated diffuse large B-cell lymphoma patients.

Diffuse aggressive B-cell lymphomas

Diffuse aggressive B-cell lymphomas comprise a relatively common and increasingly diverse group of neoplasms. Newer modalities including gene expression profiling and an increasing panel of immunohistochemical markers have contributed to greater accuracy in defining these entities. Attention is paid not only to the neoplastic cells but also to the cellular and stromal milieu in which they proliferate. These distinctions may have therapeutic implications as well, with improved outcome related to newer and sometimes targeted therapies. At the same time there is increasing understanding of the overlap, which occurs in the grey zone between diffuse large B-cell lymphoma and Burkitt lymphoma as well as between diffuse large B-cell lymphoma and Hodgkin lymphoma. This review aims to provide practical insights in the correct identification and differential diagnosis of these lymphomas, with emphasis on the changes that have occurred with the publication of the 2008 World Health Organization updated classification.

Prognostic significance of the Bcl-2 negative germinal centre in patients with diffuse large B cell lymphoma treated with R-CHOP

The classification of germinal centre (GC) and non-GC is an important prognostic immunophenotype for patients with diffuse large B cell lymphoma (DLBCL) following anthracycline-based chemotherapy. The expression of the anti-apoptotic protein, Bcl-2, has been associated with an unfavourable prognosis in patients with DLBCL. Immunohistochemistry was performed using antibodies against CD10, Bcl-6, MUM-1 and Bcl-2. To establish the combined prognosis of the immunophenotype and Bcl-2 overexpression, patients were separated into four subgroups based on their gene expression profile: the Bcl-2 positive GC subgroup, Bcl-2 negative GC subgroup, Bcl-2 positive non-GC subgroup, and the Bcl-2 negative non-GC subgroup. The clinical characteristics and survival outcomes of the four patient subgroups were compared. Ninety-six patients with de novo DLBCL received R-CHOP (rituximab, cyclophosphamide, vincristine, adriamycin and prednisone) therapy. The baseline characteristics of the patient subgroups were similar. The Bcl-2 negative GC subgroup had a favourable progression-free and overall survival (OS) compared with the other three subgroups (p = 0.042, 0.043). Multivariate analysis confirmed that the Bcl-2 negative GC group was independently associated with progression-free survival and OS. The results of this study showed that the Bcl-2 negative GC patients had the most favourable prognosis among patients with DLBCL that received R-CHOP.

Bcl-2 but not FOXP1, is an adverse risk factor in immunochemotherapy-treated non-germinal center diffuse large B-cell lymphomas

OBJECTIVES

Non-germinal center (non-GC) phenotype, high level expression of the transcription factor forkhead box protein P1 (FOXP1) and anti-apoptotic protein Bcl-2 have been identified as unfavorable prognostic factors for diffuse large B-cell lymphoma (DLBCL) patients treated with chemotherapy. Our aim was to re-evaluate the prognostic impact of these biologic factors on the survival of the patients treated with immunochemotherapy.

METHODS

Expression of Bcl-2 and FOXP1, and cell of origin based on the Hans algorithm were determined immunohistochemically from samples of 117 de novo DLBCL patients treated with R-CHOP and R-CHOEP regimens, and correlated with clinical data.

RESULTS

Consistent with our previous studies, no significant difference in 2-yr survival rates between the GC- and non-GC phenotypes was found. Both FOXP1 and Bcl-2 expression were associated with the non-GC phenotype. For all patients, no prognostic impact of FOXP1 positivity on survival was observed. However, Bcl-2 negative patients had a better survival as compared to Bcl-2 positive patients [failure free survival (FFS) 97% vs. 71%, P = 0.001 and overall survival (OS) 97% vs. 82%, P = 0.034]. When Bcl-2 related survival was analyzed in the GC- and non-GC subgroups, a significant prognostic effect of Bcl-2 on FFS was seen only in the non-GC group of patients (positive 65% vs. negative 100%, P = 0.011). A trend for the difference in OS was also observed (positive 84% vs. negative 100%, P = 0.082).

CONCLUSIONS

The data demonstrate that expression of Bcl-2 and FOXP1 is associated with the non-GC phenotype, but only Bcl-2 expression continues to be of prognostic significance in DLBCL patients treated with immunochemotherapy.

Recent prognostic factors in diffuse large B-cell lymphoma indicate NF-kappaB pathway as a target for new therapeutic strategies

The diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoid cancer. The classical chemotherapy regimen given to these patients was the CHOP (Cyclophosphamide, Hydroxydaunorubicin or Adriamycin, Oncovin or Vincristine, Prednisone or Prednisolone), but recently rituximab with CHOP (R-CHOP) increased the number of cases responding to first line therapy. DLBCL classification identified three principle subgroups. The first one, named germinal centre B cell-like (GCB), responds to both CHOP and R-CHOP treatment and it is mainly characterised by the expression of markers like Bcl-6 and CD10. The second, the activated B-cell like (ABC), has a worse prognosis in comparison with GCB, and is mainly characterised by the expression of IRF-4, PRDM1 and NF-kappaB. It is interesting to notice that IRF-4 and PRDM1 are under the transcriptional control of NF-kappaB, whose high activation level is associated with a worse prognosis. The third one, mediastinal large B-cell lymphoma (PMBCL) is an uncommon subtype characteristically found in young females. Gene expression profiling suggests that this disease resembles Hodgkin lymphoma more than other types of DLBCL. The impact of rituximab on the outcome of patients with PMBCL has still not been fully assessed. It was seen that rituximab inhibits NF-kappaB pathway in vitro. However, the clinical significance of this finding is still unknown, because both ABC and GCB DLBCL show a significant improvement of overall survival after R-CHOP treatment. In this review, the NF-kappaB pathway is suggested as a target for new chemotherapy strategies based on the association of CHOP with molecules more effective than rituximab in this pathway inhibition.

Evaluation of intra- and interobserver agreement and its clinical significance for scoring bcl-2 immunohistochemical expression in diffuse large B-cell lymphoma

Immunohistochemistry (IHC) has become an essential part of diagnosis and clinical research in lymphomas. There is considerable heterogeneity, however, in IHC findings regarding expression rate and positivity cut-offs, which creates a degree of uncertainty that has prevented its incorporation for prognostic purposes. The purpose of the present study was to assess intra- and interobserver agreement in scoring bcl-2 expression on IHC. The study materials were 81 diffuse large B-cell lymphomas. Slides were processed in the same laboratory, and were analyzed independently and in a blinded manner by four pathologists twice, at least 1 month apart. The positivity rates ranged from 31% to 41% in the first evaluation, and from 30% to 43% in the second evaluation. The two analyses by the same pathologist gave concordant results in 88-93% of cases (kappa = 0.71-0.83). Complete agreement among all observers varied from 72% to 79%. The experience of the observer did not influence intra-observer concordance. Cooperative analysis of discordant slides led to consensus in all cases. The variation observed in scoring bcl-2 expression is acceptable for use in lymphoma diagnosis and classification. The use of IHC stratification, however, for clinical decisions regarding treatment will require standardization and centralized consensus review, and must await the results of ongoing prospective trials.

Profiling of diffuse large B-cell lymphoma by immunohistochemistry: identification of prognostic subgroups

Diffuse large B-cell lymphoma (DLBCL) is a frequent lymphoma subtype with a heterogeneous behavior and a variable response to conventional chemotherapy. This clinical diversity is believed to reflect differences in the molecular pathways leading to lymphomagenesis. In this study, we have analyzed pretreatment, diagnostic samples from 108 DLBCL by immunohistology for expression of four markers linked to germinal center B-cells (CD10, Bcl-6), postgerminal center B-cells (MUM1) and apoptosis (Bcl-2). The results indicate that both CD10 and Bcl-6 are favorable prognostic indicators, in contrast to Bcl-2, which is an adverse parameter. Furthermore, using two algorithms for distinction between low- and high-risk patients proposed by Hans et al. (Blood, 2004; 103:275) and Muris et al. (Journal of Pathology, 2006; 208:714), it is shown that both are useful for predicting outcome in DLBCL. However, in this report, the algorithm of Hans et al. was superior to that of Muris et al. These findings confirm and extend other studies and indicate that different prognostic subgroups of DLBCL can be distinguished by simple immunohistological investigations for a limited number of markers. Whether these groups are also relevant for individual treatment decisions will be important to investigate in prospective studies.