Immunophenotype and intermediate‐high international prognostic index score are prognostic factors for therapy in diffuse large B‐cell lymphoma patients

BACKGROUND.

The development of gene expression profiling and tissue microarray techniques have provided more information about the heterogeneity of diffuse large B‐cell lymphoma (DLBCL), enabling categorization of DLBCL patients into 3 prognostic groups according to cell origin (but independently from the International Prognostic Index [IPI] score): germinal center (GCB), activated B‐cell (ABC), and not classified (NC) diffuse large B‐cell lymphoma. This study investigated the role of immunohistochemical discrimination between GCB and ABC&NC‐DLBCL subtypes in identifying those high‐risk patients who may benefit from a more aggressive first‐line therapeutic approach.

METHODS.

From February 2003 to August 2006, 45 newly diagnosed DLBCL patients, with IPI≥2, were considered eligible for this study: 13 had a GCB, 8 an ABC, and 24 a NC‐DLBCL. GCB patients received 6 courses of rituximab, cyclophophosphamide, doxorubicin, vinicristine, and prednisone (R‐CHOP) chemotherapy, with a subsequent, autologous stem cell transplantation in case of partial response. All ABC and NC‐DLBCL patients received 6 R‐CHOP cycles and autologous stem cell transplantation.

RESULTS.

Complete response rate for each treatment arm was 84.6% for GCB and 89.7% for ABC&NC‐DLBCL (P = .50), with a continuous complete response rate of 81.8% and 84.6%, respectively (P = .59). Projected 4‐year overall survival is 100% for GCB and 82% for ABC&NC patients (P = .12). Progression‐free survival is 77% and 79% (P = .7), respectively.

CONCLUSIONS.

The autologous stem cell transplantation consolidation in the ABC&NC‐DLBCL subtypes induced the same rate of complete response (and similar progression‐free survival rate) compared with GCB‐DLBCL. In ABC&NC‐DLBCL patients the authors observed a complete response rate of 89.7% vs. 84.6% in the GCB‐DLBCL subset, without any significant difference in progression‐free survival rate. Cancer 2010. © 2010 American Cancer Society.     

Characterization of genomic imbalances in diffuse large B‐cell lymphoma by detailed SNP‐chip analysis

The pathogenesis of diffuse large B‐cell lymphomas (DLBCL) is only partly understood. We analyzed 148 DLBCL by single nucleotide polymorphism (SNP)‐chips to characterize genomic imbalances. Seventy‐nine cases were of the germinal center B‐cell like (GCB) type of DLBCL, 49 of the activated B‐cell like (ABC) subtype and 20 were unclassified DLBCL. Twenty‐four regions of recurrent genomic gains and 38 regions of recurrent genomic losses were identified over the whole cohort, with a median of 25 imbalances per case for ABC‐DLBCL and 19 per case for GCB‐DLBCL. Several recurrent copy number changes showed differential frequencies in the GCB‐ and ABC‐DLBCL subgroups, including gains of HDAC7A predominantly in GCB‐DLBCL (38% of cases) and losses of BACH2 and CASP8AP2 predominantly in ABC‐DLBCL (35%), hinting at disparate pathogenetic mechanisms in these entities. Correlating gene expression and copy number revealed a strong gene dosage effect in all tumors, with 34% of probesets showing a concordant expression change in affected regions. Two new potential tumor suppressor genes emerging from the analysis, CASP3 and IL5RA, were sequenced in ten and 16 candidate cases, respectively. However, no mutations were found, pointing to a potential haploinsufficiency effect of these genes, considering their reduced expression in cases with deletions. Our study thus describes differences and similarities in the landscape of genomic aberrations in the DLBCL subgroups in a large collection of cases, confirming already known targets, but also discovering novel copy number changes with possible pathogenetic relevance.     

Chromosome abnormalities in diffuse large B‐cell lymphomas: analysis of 231 Chinese patients

Genome instability is a hallmark of cancer. Diffuse large B‐cell lymphoma (DLBCL) is the most common form of non‐Hodgkin lymphoma with high levels of chromosomal aberrations. The purpose of this study was to characterize chromosomal aberrations in Chinese DLBCL patients and to compare chromosomal abnormalities between germinal centre B‐cell‐like (GCB) and non‐GCB subgroups. Fluorescence in situ hybridization, G‐band cytogenetics and immunohistochemistry were performed in 231 cases of de novo DLBCL. We demonstrated that the rate of abnormal and complex karyotypes was 89.1% (139/156) and 92.8% (129/139), respectively. We found a total of 490 structural chromosomal aberrations, including 96 frequent and recurring structural alterations. Most importantly, we identified several rare or novel chromosomal alterations: eight gains (5, 13, 14q, 17, 19p, 20, 21p, Y), one loss (21) and three recurrent translocations [t(7;15)(q22;q22), t(3;20)(p24;q13.1), t(2;3)(q21;q25)]. Moreover, the frequent recurrent genomic imbalance between GCB and non‐GCB subgroups was different. Finally, we discovered two cases of concurrent IGH‐BCL6 and MYC rearrangements. The rate of abnormal karyotypes in DLBCL patients of Chinese descent was similar to that of Western countries, but some common karyotypes were different, as were the abnormal karyotypes of GCB and non‐GCB subgroups. Our discovery of rare and novel abnormal karyotypes may represent unique chromosomal alterations in Chinese DLBCL patients. Copyright © 2012 John Wiley & Sons, Ltd.     

Chromosome instability in diffuse large B cell lymphomas is suppressed by activation of the noncanonical NF‐κB pathway

Diffuse large B cell lymphoma (DLBCL) is the most common form of lymphoma in the United States. DLBCL comprises biologically distinct subtypes including germinal center‐like (GCB) and activated‐B‐cell‐like DLBCL (ABC). The most aggressive type, ABC‐DLBCL, displays dysregulation of both canonical and noncanonical NF‐κB pathway as well as genomic instability. Although, much is known about the tumorigenic roles of the canonical NF‐kB pathway, the precise role of the noncanonical NF‐kB pathway remains unknown. Here we show that activation of the noncanonical NF‐κB pathway regulates chromosome stability, DNA damage response and centrosome duplication in DLBCL. Analysis of 92 DLBCL samples revealed that activation of the noncanonical NF‐κB pathway is associated with low levels of DNA damage and centrosome amplification. Inhibiting the noncanonical pathway in lymphoma cells uncovered baseline DNA damage and prevented doxorubicin‐induced DNA damage repair. In addition, it triggered centrosome amplification and chromosome instability, indicated by anaphase bridges, multipolar spindles and chromosome missegregation. We determined that the noncanonical NF‐κB pathway execute these functions through the regulation of GADD45α and REDD1 in a p53‐independent manner, while it collaborates with p53 to regulate cyclin G2 expression. Furthermore, this pathway regulates GADD45α, REDD1 and cyclin G2 through direct binding of NF‐κB sites to their promoter region. Overall, these results indicate that the noncanonical NF‐κB pathway plays a central role in maintaining genome integrity in DLBCL. Our data suggests that inhibition of the noncanonical NF‐kB pathway should be considered as an important component in DLBCL therapeutic approach.     

Abemaciclib,a CDK4/6 inhibitor,exerts preclinical activity against aggressive germinal center‐derived B‐cell lymphomas

The revised WHO classification newly defined the entities “High‐grade B‐cell lymphoma with MYC and BCL2, and/or BCL6 rearrangements (HGBL‐DH/TH)” and “HGBL, NOS.” Standard immunochemotherapy for diffuse large B‐cell lymphoma (DLBCL), R‐CHOP, is insufficient for HGBL patients, and there are currently no optimized therapeutic regimens for HGBL. We previously reported that CCND3, which encodes cyclin D3, harbored high mutation rates in Burkitt lymphoma (BL), HGBL and a subset of DLBCL. Furthermore, the knockdown of cyclin D3 expression was toxic to germinal center (GC)‐derived B‐cell lymphomas. Thus, the fundamental function of cyclin D3 is important for the pathogenesis of GC‐derived B‐cell lymphoma. We herein used two structurally different CDK4/6 inhibitors, palbociclib and abemaciclib, and examined their suppressive effects on cell proliferation and their ability to induce apoptosis in various aggressive B‐cell lymphoma cell lines. The results obtained demonstrated that abemaciclib more strongly suppressed cell proliferation and induced apoptosis in GC‐derived B‐cell lymphoma cell lines than the control, but only slightly inhibited those features in activated B‐cell (ABC)‐like DLBCL cell lines. Palbociclib exerted partial or incomplete effects compared with the control and the effect was intermediate between abemaciclib and the control. Moreover, the effects of abemaciclib appeared to depend on cyclin D3 expression levels based on the results of the expression analysis of primary aggressive B‐cell lymphoma samples. Therefore, abemaciclib has potential as a therapeutic agent for aggressive GC‐derived B‐cell lymphomas.     

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). Copyright © 2011 John Wiley & Sons, Ltd.     

Clinicopathological analysis of methotrexate‐associated lymphoproliferative disorders: Comparison of diffuse large B‐cell lymphoma and classical Hodgkin lymphoma types

Patients with rheumatoid arthritis often develop methotrexate‐associated lymphoproliferative disorders (MTX‐LPD) during MTX treatment. MTX‐LPD occasionally regresses spontaneously after simply discontinuing MTX treatment. In patients without spontaneous regression, additional chemotherapy is required to avoid disease progression. However, the differences between spontaneous and non‐spontaneous regression have yet to be elucidated. To clarify the factors important for spontaneous regression, we analyzed the clinicopathological features of 51 patients with rheumatoid arthritis who developed MTX‐LPD (diffuse large B‐cell lymphoma [DLBCL]‐type [n = 34] and classical Hodgkin lymphoma [CHL]‐type [n = 17]). We examined the interval from MTX discontinuation to the administration of additional chemotherapy. The majority of DLBCL‐type MTX‐LPD patients (81%) exhibited remission with MTX discontinuation alone. In contrast, the majority of CHL‐type MTX‐LPD patients (76%) required additional chemotherapy. This difference was statistically significant (P = 0.001). However, overall survival was not significantly different between DLBCL‐type and CHL‐type (91% vs 94%, respectively; P > 0.05). Thus, the morphological differences in the pathological findings of MTX‐LPD may be a factor for spontaneous or non‐spontaneous regression after discontinuation of MTX.     

Combination of CD47 and signal‐regulatory protein‐α constituting the “don’t eat me signal” is a prognostic factor in diffuse large B‐cell lymphoma

The interaction between CD47 and signal‐regulatory protein‐α (SIRPα) inhibits phagocytosis, thus affecting the clinical outcomes of neoplastic diseases. Although CD47 upregulation is associated with poor prognosis in several malignancies, the effect of SIRPα expression and its coexpression with CD47 remains unclear. This study aimed to investigate the clinicopathologic effect of CD47 and SIRPα expression in diffuse large B‐cell lymphoma (DLBCL). Immunostaining of 120 biopsy samples showed that CD47 is primarily expressed in tumor cells, whereas SIRPα is expressed in nonneoplastic stromal cells, mostly macrophages. CD47^high cases showed higher MYC protein expression and lower MYC translocation. The SIRPα^high cases presented significantly shorter overall survival (OS) and progression‐free survival (PFS) than SIRPα^low cases in the activated B‐cell (ABC) subtype of DLBCL (P = .04 and P = .02, respectively). Both CD47^high and SIRPα^high presented significantly shorter OS and PFS than other cases among all DLBCL patients (P = .01 and P = .004, respectively), and the ABC type (P = .04 and P = .008, respectively) but not the germinal center B‐cell type. Both CD47^high and SIRPα^high yielded a constant independent prognostic value for OS and PFS in multivariate analysis (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.20‐7.43; P = .02; and HR, 2.87; 95% CI, 1.42‐5.85; P = .003, respectively). To the best of our knowledge, this is the first study to report that combinatorial CD47 and SIRPα expression is a potential independent prognostic factor for DLBCL. Evaluation of CD47 and SIRPα expression could be useful before CD47 blockade therapy.     

Array‐comparative genomic hybridization profiling of immunohistochemical subgroups of diffuse large B‐cell lymphoma shows distinct genomic alterations

Diffuse large B-cell lymphoma (DLBCL) displays striking heterogeneity at the clinical, genetic and molecular levels. Subtypes include germinal center B-cell-like (GCB) DLBCL and activated B-cell-like (ABC) DLBCL, according to microarray analysis, and germinal center type or non-germinal center type by immunohistochemistry. Although some reports have described genomic aberrations based upon microarray classification system, genomic aberrations based upon immunohistochemical classifications have rarely been reported. The present study aimed to ascertain the relationship between genomic aberrations and subtypes identified by immunohistochemistry, and to study the pathogenetic character of Chinese DLBCL. We conducted immunohistochemistry using antibodies against CD10, BCL6 and MUM1 in 59 samples of DLBCL from Chinese patients, and then performed microarray-based comparative genomic hybridization for each case. Characteristic genomic differences were found between GCB and non-GCB DLBCL from the array data. The GCB type was characterized by more gains at 7q (7q22.1, P < 0.05) and losses at 16q (P ≤ 0.05), while the non-GCB type was characterized by gains at 11q24.3 and 3q13.2 (P < 0.05). We found completely different mutations in BCL6+ and BCL6− non-GCB type DLBCL, whereby the BCL6− group had a higher number of gains at 1q and a loss at 14q32.13 (P ≤ 0.005), while the BCL6+ group showed a higher number of gains at 14q23.1 (P = 0.15) and losses at 6q (P = 0.07). The BCL6− group had a higher frequency of genomic imbalances compared to the BCL6+ group. In conclusion, the BCL6+ and BCL6− non-GCB type of DLBCL appear to have different mechanisms of pathogenesis.     

Higher response to lenalidomide in relapsed/refractory diffuse large B-cell lymphoma in nongerminal center B-cell-like than in germinal center B-cell-like phenotype

BACKGROUND:

There is a need to develop novel therapies for relapsed/refractory diffuse large B‐cell lymphoma (DLBCL) and to identify biomarkers predictive for therapeutic response. Lenalidomide was previously shown to induce an overall response rate (ORR) of 28% in patients with relapsed/refractory DLBCL. It is currently unknown if response rates differ between patients with different DLBCL subtypes.

METHODS:

The authors retrospectively evaluated clinical outcomes of patients with germinal center B‐cell–like versus nongerminal center B‐cell–like DLBCL treated with salvage lenalidomide at 4 academic institutions.

RESULTS:

Forty patients with relapsed/refractory DLBCL were included (24 men; 16 women; median age, 66 years; median of 4 prior treatments, including rituximab chemotherapy). Patients were classified as germinal center B‐cell–like (n = 23) or nongerminal center B‐cell–like (n = 17) DLBCL according to the Hans algorithm. The subgroups were similar in terms of stage, international prognostic index score, prior number of treatments, and rituximab resistance. A significant difference in clinical response to lenalidomide was observed in nongerminal center B‐cell–like versus germinal center B‐cell–like patients. ORR was 52.9% versus 8.7% (P = .006); complete response rate was 23.5% versus 4.3%. Median progression‐free survival was 6.2 versus 1.7 months (P = .004), although no difference in OS was observed between nongerminal center B‐cell–like and germinal center B‐cell–like DLBCL patients.

CONCLUSIONS:

The data suggest that the 2 major subgroups of patients with DLBCL (germinal center B cell and nongerminal center B cell) have different antitumor responsiveness to lenalidomide in the relapsed/refractory setting. A large international trial (NCT01197560) has been opened to enrollment in an attempt to prospectively validate these retrospective observations. Cancer 2011;. © 2011 American Cancer Society.     

Clinicopathologic correlations of diffuse large B‐cell lymphoma in rheumatoid arthritis patients treated with methotrexate

Among methotrexate (MTX)‐related lymphoproliferative disorders (MTX‐LPD), diffuse large B‐cell lymphoma (DLBCL) accounts for about half. We studied the clinicopathological characteristics and prognosis of patients with DLBCL in MTX‐LPD. This study included 29 patients who developed DLBCL after receiving MTX for rheumatoid arthritis. MTX was discontinued in all patients. Their median age was 62 years. Elevated lactate dehydrogenase (LDH) level was observed in 97% of the patients, bone marrow involvement in 17%, and involvement of extranodal sites in 41%. As for the cellular immunophenotype, CD20 was positive in 93%, CD5 in 3%, CD10 in 31%, BCL2 in 21%, BCL6 in 69%, and Epstein–Barr virus (EBV)‐encoded small non‐polyadenylated RNA (EBER) in 24%. Chemotherapy was started within 2 months after MTX withdrawal in 23 patients, of whom 12 patients received combination with rituximab. Spontaneous remission occurred in the remaining six patients. The EEBV‐positive rate was 67% (4/6), and the four EBV‐positive patients achieved complete response. Among the 23 DLBCL patients treated with chemotherapy, 20 patients achieved complete response. The 5‐year overall survival was 74% and the 5‐year progression‐free survival was 65%. After the development of DLBCL, withdrawal of MTX was the first choice of treatment. Germinal center B‐cell type and EBER‐positive patients tended to show spontaneous remission. The utility of rituximab should be examined in future studies. (Cancer Sci 2010; 101: 1309–1313)     

Multicentre phase II study of CyclOBEAP plus rituximab in patients with diffuse large B‐cell lymphoma

The R‐CHOP regimen has been found to improve the outcome of diffuse large B‐cell lymphoma (DLBCL). However, it does not provide a satisfactory treatment outcome in the high‐risk group. We previously administered the CyclOBEAP regimen to patients with DLBCL, and reported its safety and efficacy. The R‐CyclOBEAP regimen was administered over a total period of 12 weeks, and rituximab 375 mg/m² was given every 2 weeks. There were 101 eligible patients. CR was achieved in 96 patients (95%). The 5‐year overall survival (OS) rate was 85% and progression‐free survival (PFS) rate was 76%. When the patients were divided according to the IPI, the 5‐year OS and PFS rates did not significantly differ among the risk groups. The 5‐year PFS of the germinal centre B‐cell group was 80% and that of the non‐GCB group was 74% (NS). Univariate analysis showed that the presence of B symptoms, extranodal lesions ≧2, and sIL‐2R were significant poor prognostic factors. Grade 4 neutropenia was observed in 91 patients and thrombocytopenia in 9 patients. The addition of rituximab to CyclOBEAP therapy may enhance the effect of CyclOBEAP therapy for DLBCL. Copyright © 2010 John Wiley & Sons, Ltd.     

CD5 expression correlates with inferior survival and enhances the negative effect of p53 overexpression in diffuse large B‐cell lymphoma

De novo CD5‐positive diffuse large B‐cell lymphoma (CD5+ DLBCL) is increasingly recognized as a distinct pathologic phenomenon with a specific clinical picture. However, CD5+ DLBCL has not been studied on a large scale in China. In this study, we show that CD5+ DLBCL occurs at a low frequency (9.2%). Comparison of clinical characteristics of CD5+ vs CD5? DLBCL showed that CD5+ DLBCL was more frequently elderly (>60 years) and had B symptoms, high‐performance status, stage III‐IV, an IPI score >2 and bone marrow involvement. Patients with CD5+ DLBCL had tumours with a higher prevalence of BCL‐2 and p53 overexpression than CD5? DLBCL. Patients with CD5+ DLBCL had inferior progression‐free survival (PFS) and overall survival (OS) than did patients with CD5? DLBCL. For CD5+ DLBCL, the patients who were treated with rituximab showed significantly better PFS and OS than those treated without rituximab. However, patients treated with RCHOP showed similar PFS and OS when compared with the group treated with intensive therapy. In addition, patients with p53 and CD5 co‐expression had the worst PFS and OS. In conclusion, CD5+ DLBCL was associated with unfavorable clinicopathologic variables and with inferior survival. CD5+ DLBCL has a high frequency of p53 overexpression, and CD5 augments the negative effect of p53 overexpression in DLBCL.     

MicroRNA expression distinguishes between germinal center B cell-like and activated B cell-like subtypes of diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is an aggressive malignancy that accounts for nearly 40% of all lymphoid tumors. This heterogeneous disease can be divided into germinal center B cell-like (GCB) and activated B cell-like (ABC) subtypes by gene expression and immunohistochemical profiling. Using microarray analysis on prototypic cell lines, we identified microRNAs (miR-155, miR-21 and miR-221) that were more highly expressed in ABC-type than GCB-type cell lines. These microRNAs were over-expressed in de novo DLBCL (n = 35), transformed DLBCL (n = 14) and follicular center lymphoma cases (n = 27) compared to normal B cells. Consistent with the cell line model, expression levels were higher in DLBCL cases with an ABC-type immunophenotype than those that were GCB-type (p < 0.05). Moreover, using multivariate analysis we found that expression of miR-21 was an independent prognostic indicator in de novo DLBCL (p < 0.05). Interestingly, expression levels of both miR-155 and miR-21 were also higher in nonmalignant ABC than in GCB cells. As we also demonstrate that expression of microRNAs can be measured reliably from routine paraffin-embedded biopsies of more than 8-years-old (p < 0.001), we suggest that microRNAs could be clinically useful molecular markers for DLBCL as well as other cancers.     

PD‐L1 expression is low in large B‐cell lymphoma with MYC or double‐hit translocation

In large B‐cell lymphoma (LBCL), MYC translocation and MYC/BCL2 or MYC/BCL6 double hit (DH) are associated with poor prognosis, and there is an unmet need for novel treatment targets in this patient group. Treatments targeting the PD‐L1/PD‐1 pathway are still poorly elucidated in LBCL. PD‐L1 expression might predict response to treatment targeting the PD‐L1/PD‐1 pathway. We therefore investigated the relationship between PD‐L1 protein and mRNA expression levels and MYC and DH translocation in LBCL. We detected MYC, BCL2, and BCL6 translocation by fluorescent in situ hybridization in tissue samples from 130 patients randomly selected from two cohorts of patients with LBCL: 49 patients with MYC translocation of whom 36 had DH and 81 without MYC translocation. PD‐L1 protein expression was detected by immunohistochemistry (IHC) in tissue samples from 77 patients and PD‐L1 mRNA expression by next‐generation RNA sequencing (NGS) in another 77 patients. Twenty‐four patients overlapped, ie, were analysed with both IHC and NGS. Nonparametric tests were performed to evaluate intergroup differences. PD‐L1 protein expression level was significantly lower in patients with MYC (n = 42, median = 3.3%, interquartile range [IQR] 0.0‐10.8) or DH translocations (n = 31, median = 3.3%, IQR 0.0‐10.0) compared with patients with no MYC (n = 35, median = 16.7%, IQR 3.3‐30.0) or no DH translocations (n = 46, 13.3%, IQR 2.5‐30.0), P = .004 and P ≤ .001, respectively. PD‐L1 mRNA expression was also significantly lower in patients with MYC or DH translocations, P = .001 and P = .006, respectively. Higher PD‐L1 protein and mRNA expression levels were associated with non–germinal centre (GC) type compared with germinal centre B‐cell (GCB)‐type diffuse LBCL (DLBCL), P = .004 and P = .002, respectively. In conclusion, we report an association between low PD‐L1 expression and MYC and DH translocation in patients with LBCL. Our findings may indicate that patients with MYC or DH translocation may benefit less from treatment with PD‐L1/PD‐1‐inhibitors compared with patients without these translocations. This should be evaluated in larger, prospective, consecutive trials.     

The therapeutic effect of rituximab on CD5‐positive and CD5‐negative diffuse large B‐cell lymphoma

The prognosis of diffuse large B‐cell lymphoma (DLBCL) has improved markedly in recent years of rituximab era. The prognosis of de novo CD5‐positive DLBCL is reported to be poor, but the effect of rituximab on this type of lymphoma remains unclear. To investigate the effect of rituximab on CD5‐positive DLBCL, we collected DLBCL patients and analysed prognostic factors. A total of 157 patients with DLBCL who were immunophenotyped with flow‐cytometry (FCM) and treated with chemotherapy were subjected to analysis. Those treated with radiotherapy alone or with supportive therapy only were not included. Patients diagnosed in 2003 or later were treated with rituximab combined chemotherapy. There were 95 males and 62 females. Their age ranged from 20 to 91 years old, and the median was 65 years. Nineteen patients were diagnosed as having de novo CD5‐positive DLBCL. Rituximab was given alongside chemotherapy in 85 patients. Of these, 11 were positive for CD5 and 74 were negative. The addition of rituximab improved the overall survival (OS) of DLBCL patients (2‐year OS: 82% vs. 70%, p = 0.01). For CD5‐negative DLBCL, patients treated with rituximab showed 2‐year OS of 84%, which was significantly better than those treated without rituximab (70%, p = 0.008). However, for CD5‐positive DLBCL, the prognosis was not statistically different between the patients treated with and without rituximab (59% vs. 50%, p = 0.72). Although rituximab improved the prognosis of DLBCL, such improvement was restricted to the CD5‐negative group. Further investigation is required to improve the prognosis of patients with CD5‐positive DLBCL. Copyright © 2009 John Wiley & Sons, Ltd.     

Leukemic High Grade B Cell Lymphoma is Associated With MYC Translocation,Double Hit/Triple Hit Status,Transformation, and CNS Disease Risk: The Mayo Clinic Experience

Introduction: Leukemic involvement in high grade B cell lymphoma (L-HGBL) is rare and has been sparsely described in the literature. We report our experience in a large single institution multicenter academic setting. Materials and Methods: Medical records of patients with HGBL who received care at Mayo Clinic between 2003 and 2020 were reviewed. L-HGBL was confirmed by peripheral blood smear and flow cytometry with corroboration from tissue and bone marrow biopsy findings. Results: Twenty patients met inclusion criteria. All patients had significant bone marrow involvement by HGBL. Leukemic involvement presented in 11 of 20 (55%) in the de novo and 9 of 20 (45%) in the relapsed setting. Seven of 20 patients had DLBCL, NOS, 6 of 20 had transformation (t-DLBCL), 3 of 20 had transformed double/triple hit lymphoma (t-DHL/THL), 2 of 20 had double hit lymphoma (DHL), and 2 of 20 had HGBL with intermediate features between DLBCL and Burkitt lymphoma. Nine of 15 patients had MYC translocation. Based on Hans criteria, 11 of 20 had germinal center B-cell (GCB) cell of origin (COO) and 9/20 had non-GCB COO. Five of 11 de novo patients experienced CNS relapse/progression. All de novo patients received anthracycline-based chemoimmunotherapy. Eighteen of 20 patients died of progressive disease. Median overall survival was significantly better in the de novo compared to relapsed group (8.9 months vs. 2.8 months, P = .01). COO, MYC status, DHL/THL status, HGBL subtype, or treatment group did not demonstrate a significant effect on overall survival. Conclusion: L-HGBL carries a poor prognosis and is associated with MYC translocation, DHL/THL status, transformation, and high CNS risk. Novel therapeutic approaches are needed for L-HGBL.     

Epstein–Barr virus presence in pediatric diffuse large B‐cell lymphoma reveals a particular association and latency patterns: Analysis of viral role in tumor microenvironment

Non‐Hodgkin's lymphoma represents 6–10% of pediatric malignancies, and diffuse large B‐cell lymphoma (DLBCL) is one of the three major subtypes. The 2008 WHO classification included a new entity, Epstein–Barr virus (EBV)‐positive DLBCL of the elderly, affecting patients >50 years. It has been demonstrated that EBV may play a role in tumor microenvironment composition, disturbing antitumor immune response and disease progression. As most studies were performed in adults, our aim was to assess EBV presence and latency pattern, as well as T‐cell microenvironment in a pediatric DLBCL series of Argentina. The study was conducted on formalin‐fixed paraffin‐embedded biopsies from 25 DLBCL patients. EBV‐encoded small nuclear early regions (EBERs) expression was performed by in situ hybridization, whereas EBV gene expression was analyzed using real‐time PCR. Epstein–Barr virus latent membrane proteins (LMP)1, LMP2A, CD3, CD4, CD8 and Foxp3 expression were assessed by immunohistochemistry (IHC). Forty percent of cases showed EBV expression, with a significantly higher incidence among patients <10 years (p = 0.018), and with immunosuppressed (p = 0.023). T‐cell subsets were not altered by EBV presence. Full EBV latency antigen expression (latency type III) was the most frequently pattern observed, together with BZLF1 lytic gene expression. One patient showed II‐like pattern (LMP1 without LMP2A expression). Based exclusively on IHC, some patients showed latency II/III (EBERs and LMP1 expression) or I (EBERs only). These findings suggest that EBV association in our series was higher than the previously demonstrated for elderly DLBCL and that EBV latency pattern could be more complex from those previously observed. Therefore, EBV could be an important cofactor in pediatric DLBCL lymphomagenesis.     

Diffuse large B‐cell lymphoma

BACKGROUND:

The objective of this study was to compare the clinical features and prognosis of patients with diffuse large B‐cell lymphoma (DLBCL) of Waldeyer ring (WR‐DLBCL) and patients with lymph node DLBCL (N‐DLBCL).

METHODS:

One hundred eighty‐one patients with WR‐DLBCL and N‐DLBCL were reviewed. There were 57 patients with stage I disease, 83 patients with stage II disease, 26 patients with stage III disease, and 15 patients with stage IV disease. Among them, 101 patients had primary N‐DLBCL, and 80 patients had primary WR‐DLBCL.

RESULTS:

Patients with WR‐DLBCL and N‐DLBCL usually presented at an older age and had localized disease, a low frequency of B symptoms, a good performance status, and a low‐risk International Prognostic Index (IPI) score. Compared with patients who had N‐DLBCL, patients who had WR‐DLBCL presented with more stage II disease and lower tumor burdens. The overall response rate after treatment was similar in both groups. The 5‐year overall survival (OS) and progression‐free survival (PFS) rates were 76% and 61% in patients with WR‐DLBCL, respectively, and 56% and 50% in patients with N‐DLBCL, respectively (P = .119 for OS; P = .052 for PFS). IPI scores and elevated β2‐microglobulin and LDH levels were associated with a poor prognosis for patients who had WR‐DLBCL; whereas bulky tumor, elevated β2‐microglobulin levels, and IPI scores were associated with poor OS for patients who had N‐DLBCL.

CONCLUSIONS:

The current results supported the continued inclusion of WR‐DLBCL as a lymph node group in the staging of DLBCL. Patients with WR‐DLBCL had clinical features and prognosis similar to those of patients with N‐DLBCL. Cancer 2009. © 2009 American Cancer Society.