Prognostic impact of history of follicular lymphoma, induction regimen and stem cell transplant in patients with MYC/BCL2 double hit lymphoma

Aggressive B-cell non-Hodgkin lymphomas: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Aggressive B-cell non-Hodgkin lymphomas are a heterogeneous group of diseases and our concepts are evolving as we learn more about their clinical, pathologic, molecular genetic features. Session IV of the 2020 EAHP Workshop covered aggressive, predominantly high-grade B-cell lymphomas, many that were difficult to classify. In this manuscript, we summarize the features of the submitted cases and highlight differential diagnostic difficulties. We specifically review issues related to high-grade B-cell lymphomas (HGBCLs) with MYC and BCL2 and/or BCL6 rearrangements including TdT expression in these cases, HGBCL, not otherwise specified, large B-cell lymphomas with IRF4 rearrangement, high-grade/large B-cell lymphomas with 11q aberration, Burkitt lymphoma, and pleomorphic mantle cell lymphoma. Since the workshop, the 5th edition of the WHO Classification for Haematolymphoid Tumours (WHO-HAEM5) and International Consensus Classification (ICC) 2022 were published. We endeavor to use the updated terminology.

Myc rearrangement and concurrent high protein expression of C-Myc/Bcl2 carry an adverse prognosis in diffuse large B-cell lymphoma

PURPOSE

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of non-Hodgkin lymphoma, characterized by a variety of clinicopathological, histomorphological, immunophenotypic, and molecular genetic features. The subtype of DLBCL known as double-expressor lymphoma (DEL) is associated with an adverse prognosis when treated with R-CHOP. Our study aimed to investigate the clinicopathologic features of DEL and the prognostic roles of Myc rearrangement and C-Myc expression in DEL patients.

PATIENTS AND METHODS

We conducted a retrospective study of 145 patients who were identified through fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) testing.

RESULTS

We found that DEL patients were more likely to have a non-germinal center B-cell (GCB) subtype, stage III/IV disease, and a high International Prognostic Index (IPI) score. Our survival analysis indicated that Myc rearrangement and C-Myc expression were associated with poor prognosis. Although DEL patients with Myc rearrangement exhibited trends towards worse survival compared with patients without Myc rearrangement, the differences were not statistically significant (P = 0.4008). The median overall survival (OS) of DEL patients with ≥70 % C-Myc expression (DEL-C-Mychigh) was 5 months. In the DEL-C-Mychigh group, the non-GCB subtype showed nonsignificant trends towards poorer survival compared with the GCB subtype (P = 0.1042).

CONCLUSION

In conclusion, our study shows that a cut-off of ≥70 % for C-Myc expression in DEL patients can improve risk stratification, and suggests that more intensive treatment regimens may be necessary to improve survival in this high-risk population.

Induction treatment in high-grade B-cell lymphoma with a concurrent MYC and BCL2 and/or BCL6 rearrangement: a systematic review and meta-analysis

Background and aim

High-grade B cell lymphomas with concomitant MYC and BCL2 and/or BCL6 rearrangements (HGBCL-DH/TH) have a poor prognosis when treated with the standard R-CHOP-like chemoimmunotherapy protocol. Whether this can be improved using intensified regimens is still under debate. However, due to the rarity of HGBCL-DH/TH there are no prospective, randomized controlled trials (RCT) available. Thus, with this systematic review and meta-analysis we attempted to compare survival in HGBCL-DH/TH patients receiving intensified vs. R-CHOP(-like) regimens.

Methods

The PubMed and Web of Science databases were searched for original studies reporting on first-line treatment in HGBCL-DH/TH patients from 08/2014 until 04/2022. Studies with only localized stage disease, ≤10 patients, single-arm, non-full peer-reviewed publications, and preclinical studies were excluded. The quality of literature and the risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) and National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random-effect models were used to compare R-CHOP-(like) and intensified regimens regarding 2-year overall survival (2y-OS) and 2-year progression-free survival (2y-PFS).

Results

Altogether, 11 retrospective studies, but no RCT, with 891 patients were included. Only four studies were of good quality based on aforementioned criteria. Intensified treatment could improve 2y-OS (hazard ratio [HR]=0.78 [95% confidence interval [CI] 0.63-0.96]; p=0.02) as well as 2y-PFS (HR=0.66 [95% CI 0.44-0.99]; p=0.045).

Conclusions

This meta-analysis indicates that intensified regimens could possibly improve 2y-OS and 2y-PFS in HGBCL-DH/TH patients. However, the significance of these results is mainly limited by data quality, data robustness, and its retrospective nature. There is still a need for innovative controlled clinical trials in this difficult to treat patient population.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42022313234.

Double‑hit primary lymphoma (MYC and BCL2) in the bilateral ovary: A case report

Lymphoid neoplasm with 18q21.3/BCL2 and 8q24/MYC translocation to immunoglobulin genes as dual-hit lymphoma in female bilateral ovaries is rare and has a poor clinical outcome. The present study reported on the case of a 33-year-old female, who was admitted to the hospital due to lower abdominal distension aggravated during defecation but with no obvious inducement. The B-ultrasound revealed bilateral adnexal solid masses and the pathological examination indicated advanced B-cell lymphoma (HGBL) with MYC and BCL2 gene rearrangement. The patient then received R-CHOP treatment, but the effects were poor. Rare extranodal HGBL presentations with MYC and BCL2 rearrangement should be considered in the differential diagnosis of masses at unusual sites, such as the adnexa. Due to their aggressive nature, early and prompt recognition of these lymphomas is essential for appropriately administering therapies.

High-grade B-cell lymphoma (HGBL)-NOS is clinicopathologically and genetically more similar to DLBCL/HGBL-DH than DLBCL

High-grade B-cell lymphoma, not otherwise specified (HGBL-NOS) is rare and data focused on these neoplasms is lacking. We studied the clinicopathologic and genetic features of 136 HGBL-NOS patients and compared them to patients with DLBCL/HGBL-DH (n = 224, defined by 5th Edition WHO) and DLBCL (n = 217). HGBL-NOS patients had clinical features similar to DLBCL/HGBL-DH patients. MYC rearrangement (MYC-R) was present in 43% of HGBL-NOS. With induction regimen similar to DLBCL/HGBL-DH patients, HGBL-NOS patients had a median overall survival (OS) of 28.9 months, similar to DLBCL/HGBL-DH (p = 0.48) but inferior to DLBCL patients (p = 0.03). R-EPOCH induction was associated with improved OS compared with R-CHOP. MYC-R, history of lymphoma, and high IPI were independent adverse prognostic factors in HGBL-NOS patients. Whole transcriptome profiling performed on a subset of HGBL-NOS cases showed a profile more similar to DLBCL/HGBL-DH than to DLBCL; 53% of HGBL-NOS had a DH-like signature (DH-like-Sig) and were enriched for MYC-R. DH-like-Sig+ HGBL-NOS patients had a poorer OS than DH-like-Sig-negative patients (p = 0.04). In conclusion, HGBL-NOS has clinicopathologic features and a gene expression profile more similar to DLBCL/HGBL-DH than to DLBCL. Cases of HGBL-NOS frequently carry MYC-R and have a DH-like-Sig+. R-EPOCH induction in HGBL-NOS appears associated with improved OS compared with standard R-CHOP.

Copy Number Alteration and Mutational Profile of High-Grade B-Cell Lymphoma with MYC and BCL2 and/or BCL6 Rearrangements, Diffuse Large B-Cell Lymphoma with MYC-Rearrangement, and Diffuse Large B-Cell Lymphoma with MYC-Cluster Amplification

Diffuse large B-cell lymphoma (DLBCL) with MYC alteration is classified as high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double/triple-hit lymphoma; DHL/THL), DLBCL with MYC rearrangement (single-hit lymphoma; SHL) and DLBCL with MYC-cluster amplification (MCAD). To elucidate the genetic features of DHL/THL, SHL, and MCAD, 23 lymphoma cases from Tokai University Hospital were analyzed. The series included 10 cases of DHL/THL, 10 cases of SHL and 3 cases of MCAD. The analysis used whole-genome copy number microarray analysis (OncoScan) and a custom-made next-generation sequencing (NGS) panel of 115 genes associated with aggressive B-cell lymphomas. The copy number alteration (CNA) profiles were similar between DHL/THL and SHL. MCAD had fewer CNAs than those of DHL/THL and SHL, except for +8q24. The NGS profile characterized DHL/THL with a higher "mutation burden" than SHL (17 vs. 10, p = 0.010), and the most relevant genes for DHL/THL were BCL2 and SOCS1, and for SHL was DTX1. MCAD was characterized by mutations of DDX3X, TCF3, HLA-A, and TP53, whereas MYC was unmutated. In conclusion, DHL/THL, SHL, and MCAD have different profiles.

Blastoid high-grade B-cell lymphoma initially presenting in bone marrow: a diagnostic challenge

The 2016 WHO classification introduced the category of high-grade B-cell lymphoma (HGBL), which includes one poorly understood subset, blastoid-HGBL. Establishing the diagnosis and distinguishing blastoid-HGBL from B-acute lymphoblastic leukemia (B-ALL) in bone marrow can be challenging. We assessed 31 cases of blastoid-HGBL diagnosed initially in bone marrow and compared this group to 36 cases of B-ALL using immunophenotyping, fluorescence in situ hybridization, and targeted next generation sequencing analysis. The 31 blastoid-HGBL cases included 14 HGBL with MYC and BCL2 and/or BCL6 rearrangements (double hit lymphoma, DHL), 13 HGBL, not otherwise specified (NOS), and four cases with TdT expression that were difficult to classify. Compared with B-ALL, blastoid-HGBL cases more often showed increased intensity/bright expression of CD20, CD38, CD45, BCL-6, and MYC, and less frequent bright expression of CD10 and TdT. Cases of blastoid-HGBL also more frequently had MYC rearrangement, a complex karyotype and TP53 mutation (p < 0.01). With the exception of CD34, no other single factor, including TdT, was sensitive or adequately specific to distinguish blastoid-HGBL from B-ALL. We developed a scoring system using six distinctive features between 16 cases of unequivocal blastoid HGBL and 22 cases of CD34-positive B-ALL, with a score of ≥3 defining blastoid-HGBL. The system was further validated by using 15 cases of surface light chain negative, and/or CD45 dim to negative blastoid-HGBL and 14 cases of CD34-negative B-ALL. The sensitivity, specificity, positive, and negative predictive value of this scoring system were 100%, 94%, 94%, and 100%, respectively. Using this system, the four cases with TdT expression were all classified as blastoid-HGBL: three were DHL and one was HGBL-NOS. In conclusion, blastoid-HGBL shows distinctive immunophenotypic, cytogenetic, and molecular features as compared with B-ALL. The proposed scoring system can be helpful for the classification of diagnostically challenging blastoid lymphoid tumors presenting initially in the bone marrow.

AID is a poor prognostic marker of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements

Diffuse large B-cell lymphoma with MYC rearrangement is defined as double/triple-hit lymphoma (DHL/THL) or single-hit lymphoma (SHL) by the inclusion of the BCL2 and BCL6 rearrangements status. DHL/THL is called as "high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements" in the World Health Organization 2017 Classification of Tumors of Hematopoietic and Lymphoid Tissues. To find a prognostic biomarker of DHL/THL, we firstly examined 19 cases (molecular analysis series;10 cases of DHL/THL and 9 cases of SHL) with gene expression profile analysis. The gene expression profile analysis showed that the high expression of AICDA was associated with an adverse prognosis in DHL/THL, but not in SHL. Then, we evaluated immunohistochemical expression of AID, the protein product of AICDA, in 50 cases (molecular analysis series of 19 cases and additional immunohistochemistry series of 31 cases; 12 cases of DHL/THL and 19 cases of SHL) and confirmed that its expression was also associated with an adverse prognosis in DHL/THL. Therefore, AICDA and AID can be a predictor of an adverse clinical outcome in DHL/THL and immunohistochemistry of AID is useful to find DHL/THL-adverse prognosis group.

Modified conditioning regimen with chidamide and high-dose rituximab for triple-hit lymphoma

Triple-hit lymphoma (THL), which is classified into high-grade B-cell lymphoma with rearrangements of MYC, BCL2 and BCL6, presents aggressive biological behaviour. High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) is considered to be one of the recommended treatment options. Here, we reported 3 THL patients received carmustine, etoposide, cytarabine and cyclophosphamide (BEAC) combined with chidamide and high-dose rituximab conditioning regimen and found that this conditioning showed good efficacy and tolerance without increase of adverse events.

Molecular Update and Evolving Classification of Large B-Cell Lymphoma

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity. The application of high throughput technologies to the study of lymphomas has yielded abundant molecular data leading to the identification of distinct molecular identities and novel pathogenetic pathways. In light of this new information, newly refined diagnostic criteria have been established in the fourth edition of the World Health Organization (WHO) consensus classification of lymphomas, which was revised in 2016. This article reviews the histopathological and molecular features of the various aggressive B-cell lymphoma subtypes included in the updated classification.

Relative frequency and clinicopathologic characteristics of MYC-rearranged follicular lymphoma

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance.

MYC rearrangement but not extra MYC copies is an independent prognostic factor in patients with mantle cell lymphoma

Mantle cell lymphoma (MCL) with MYC rearrangement (MYC-R) is rare and little is known about the importance of MYC extra copies (EC) in the absence of MYC-R in MCL patients. This study includes 88 MCL patients with MYC tested by fluorescence in situ hybridization and/or conventional cytogenetics, including 27 with MYC-R, 21 with MYC-EC, and 40 with normal (NL) MYC. MCL patients with MYC-R more often had blastoid/pleomorphic morphology; a higher frequency of CD10, MYC, and simultaneous MYC and BCL2 expression; a higher level of MYC; and a higher Ki67 proliferation rate (p<0.05) than those without MYC-R. Although patients with MYC-R more frequently received aggressive chemotherapy (p=0.001), their overall survival (OS) was significantly shorter than those without MYC-R. Compared with patients with MYC/BCL2 double hit lymphoma (DHL), patients with MYC-R MCL had a similar OS but more commonly had bone marrow involvement, stage 4 disease, and a different immunophenotype. MCL patients with MYC-EC showed an OS intermediate between those with MYC-R and MYC-NL, either all or only blastoid/pleomorphic MCL patients included. Multivariate analysis showed that MYC-R, but not MYC-EC, had an independent and negative impact on OS. In conclusion, MYC-R but not MYC-EC showed a higher MYC expression and is an adverse prognostic factor for MCL patients. Although the OS of MCL patients with MYC-R is similar to that of MYC/BCL2 DHL patients, these groups have different clinicopathologic features supporting the retention of MCL with MYC-R in the category of MCL, as recommended in the revised World Health Organization classification.

Establishment and characterization of a novel 'double-hit' follicular lymphoma cell line, FL-SJC

About 5 per cent of follicular lymphoma (FL) cases are double-hit (DH) lymphomas. Double-hit follicular lymphoma (DHFL) cell lines can improve our understanding and drug development on FL. But there are only few DHFL cell lines. Here, we established a new MYC/BCL2 DHFL cell line, FL-SJC. The cells were obtained from the hydrothorax of a patient with MYC/BCL2 DHFL and cultured for 140 passages in vitro. FL-SJC cells demonstrated CD19⁺⁺ , CD20⁺ , CD22⁺⁺ , HLA-DR⁺ , CD10⁺ , CD38⁺ , Lambda⁺ CD23^- , CD5^- and Kappa^- . The chromosome karyotypic analysis confirmed the co-existence of t(8;22)(q24;q11) and t(14;18)(q32;q21), as well as additional abnormalities involving chromosomes 2 and 3. Fluorescence in situ hybridization analysis (FISH) showed IGH/BCL2 fusion gene and the MYC rearrangement. In addition, the FL-SJC cells displayed KMT2D/MLL2 and CREBBP gene mutations. After subcutaneous inoculation of FL-SJC cells, the SCID mice developed solid tumour masses within 6-8 weeks. FL-SJC cells were proven to be free of Epstein-Barr (EB) virus infection and be multidrug-resistant. In a conclusion, the FL-SJC cell line has been identified as a novel MYC/BCL2 double-hit follicular lymphoma that can be used as a potentially available tool for the clinical and basic research, together with the drug development for MYC/BCL2 DHFL.

Challenges and Opportunities for High-grade B-Cell Lymphoma With MYC and BCL2 and/or BCL6 Rearrangement (Double-hit Lymphoma)

The most common subtype of non-Hodgkin lymphoma, diffuse large B-cell lymphoma, is cured in approximately two thirds of patients after initial therapy. The remaining one-third of patients who suffer relapse or become refractory have very poor survival outcomes despite salvage chemotherapy with or without stem cell transplantation. A considerable proportion of relapsed or refractory large B cells belong to the WHO subtype known as high-grade B-cell lymphoma with rearrangement of MYC and BCL2 and/or BCL6, also known as double-hit lymphoma (DHL). Most DHL patients present with Ann Arbor's stage III/IV, a comparatively higher rate of extranodal involvement including bone marrow and central nervous system infiltration, high levels of lactate dehydrogenase, and an elevated Ki67 expression in the tumor cells. Newer therapeutic approaches, including targeted therapy against BCL2, MYC, or other associated pathways, are needed. In addition, recent therapies that harness the immune system, such as checkpoint inhibitors and chimeric antigen receptor T-cell therapy, are changing the paradigm of treatment for non-Hodgkin lymphoma and could impact the outcome of DHL.

[The role of translocations involving c-MYC/8q24, BCL2/18q21 and/or BCL6/3q27 genes in patients with follicular lymphoma. Retrospective analysis of single - centre data]

Aim of the issue was to compare clinical characteristics and treatment results of patients with follicular lymphoma (FL) with translocations involving loci of c-MYC/8q24, BCL2/18q21 and/or BCL6/3q27 genes and patients with high - grade B-cell lymphoma [High - grade B-cell lymphoma (HGBL), double - hit (DH)]. Materials and methods. Since 2004 to 2017 years in National Research Center for Hematology 12 patients with high - grade B-cell lymphoma double - hit (HGBL DH) and 6 FL patients with translocations involving c-MYC and BCL2 and/or BCL6 had been treated. We performed a comparative analysis of clinical characterisctics in both groups. As primary endpoints was assessed frequency of complete remission (CR) or progressive disease (PD); as secondary endpoints - overall (OS) and event - free survival (EFS). Results. 5 patients with HGBL DH had c-MYC/BCL6, 7 - c-MYC/BCL2 rearrangements; 2 patients with FL had c-MYC/BCL2, 3 - c-MYC/BCL6, 1 - c-MYC/BCL2/BCL6 rearrangements. FL was represented by grade 3A in 2, grade 3B - in 4 cases, 3 of them had large - cell transformation. In HGBL DH and FL patients had no significant differences in clinical characteristics. The majority of patients had a widespread tumour, increased LDH activity, high frequency of extranodal and bone marrow involvement. Ki-67 expression level was lower in patients with FL (p.

Frontline treatment of diffuse large B-cell lymphoma: Beyond R-CHOP

Although the majority of patients with diffuse large B-cell lymphoma (DLBCL) can be cured with the standard immunochemotherapy R-CHOP, one-third of them relapses with a dismal outcome in most cases. In the recent years, remarkable advances have been achieved based on the discovery of molecular genetics in DLBCL. In addition to the major cell-of-origin designations of germinal center B-cell and activated B-cell subtypes, next-generation sequencing has unveiled the remarkable complexity of DLBCL and identified potential molecular targets for tailored therapies. Despite these findings, the current standard of care for DLBCL patients is still R-CHOP, and optimization of frontline therapy remains an important goal. In this review, we summarize recent updates on the evolution of frontline therapies for DLBCL.

MYC/BCL2/BCL6 triple hit lymphoma: a study of 40 patients with a comparison to MYC/BCL2 and MYC/BCL6 double hit lymphomas

High-grade B-cell lymphomas with MYC, BCL2, and BCL6 rearrangements (triple hit lymphoma) are uncommon. We studied the clinicopathologic features of 40 patients with triple hit lymphoma and compared them to 157 patients with MYC/BCL2 double hit lymphoma and 13 patients with MYC/BCL6 double hit lymphoma. The triple hit lymphoma group included 25 men and 15 women with a median age of 61 years (range, 34-85). Nine patients had a history of B-cell lymphoma. Histologically, 23 (58%) cases were diffuse large B-cell lymphoma and 17 cases had features of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma. Most cases of triple hit lymphoma were positive for CD10 (100%), BCL2 (95%), BCL6 (82%), MYC (74%), and 71% with MYC and BCL2 coexpression. P53 was overexpressed in 29% of triple hit lymphoma cases. The clinicopathological features of triple hit lymphoma patients were similar to patients with MYC/BCL2 and MYC/BCL6 double hit lymphoma, except that triple hit lymphoma cases were more often CD10 positive compared with MYC/BCL6 double hit lymphoma (p < 0.05). Induction chemotherapy used was similar for patients with triple hit lymphoma and double hit lymphoma and overall survival in triple hit lymphoma patients was 17.6 months, similar to the overall survival of patients with double hit lymphoma (p = 0.67). Patients with triple hit lymphoma showing P53 overexpression had significantly worse overall survival compared with those without P53 overexpression (p = 0.04). On the other hand, double expressor status and prior history of B-cell lymphoma did not correlate with overall survival. In conclusion, most patients with triple hit lymphoma have an aggressive clinical course and poor prognosis and these tumors have a germinal center B-cell immunophenotype, similar to patients with double hit lymphomas. P53 expression is a poor prognostic factor in patients with triple hit lymphoma.

Advances in pathological understanding of high-grade B cell lymphomas

INTRODUCTION

The designation high-grade B-cell lymphoma (HGBL) has been incorporated into the 2016 Revision of the WHO classification of lymphoid neoplasms and includes two types: (1) HGBL, not otherwise specified; and (2) HGBL with MYC and BCL2 and/or BCL6 rearrangements, also known as double or triple hit lymphoma (DHL/THL). These categories of lymphomas represent 1-2% of non-Hodgkin lymphomas and a considerable portion of DLBCL patients who are primary refractory to R-CHOP therapy. It corresponds to the designation 'B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma' in the 2008 WHO classification. Areas covered: This paper provides an update of HGBL, focusing on their pathologic features, prognosis, and diagnostic workup. It highlights advances in our understanding of DHL/THL. Expert commentary: The diagnosis relies on FISH testing and the major controversial question is when to perform it to diagnose virtually all DHL/THL cases, but also being cost effective. Currently there is no consensus. Considering the high refractory rate of these patients to standard R-CHOP induction, the authors recommend FISH testing in all newly diagnosed large B-cell lymphoma by using our stepwise test strategy. With the progress of molecular genetics, the prognosis will be further stratified and HGBL-NOS maybe further evolve too.

Inferior survival in high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements is not associated with MYC/IG gene rearrangements

High-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements (double-/triple-hit lymphoma) have an aggressive clinical course. We investigated the prognostic value of transformation from low-grade lymphoma, cytological features (high grade versus large cell), MYC rearrangement partners (immunoglobulin versus nonimmunoglobulin gene), and treatment. We evaluated 100 adults with double-/triple-hit lymphoma, reviewing cytological features; cell of origin; and rearrangements of MYC, BCL2, and BCL6 using MYC, BCL2, and BCL6 break-apart and IGH/MYC, IGL/MYC, IGK/MYC, and IGH/BCL2 dual-fusion interphase fluorescence in situ hybridization probes. Outcome analysis was restricted to patients with lymphoma, de novo or at transformation, who received anthracycline-based chemotherapy. Among them, 60% had high-grade cytological features; 91% had a germinal center B-cell phenotype, and 60% had a MYC/IG rearrangement. Germinal center B-cell phenotype was associated with BCL2 rearrangements (P<0.001). Mean (95% confidence interval) 5-year overall survival was 49% (37%–64%). Transformation from previously treated and untreated low-grade lymphoma was associated with inferior overall survival (hazard ratio, 2.99; P=0.008). Patients with high-grade cytological features showed a non-significant tendency to inferior outcome (hazard ratio, 2.32; P=0.09). No association was observed between MYC rearrangement partner and overall survival (hazard ratio, 1.00; P=0.99). Compared with patients receiving rituximab, cyclophosphamide, doxorubicin, and vincristine (R-CHOP) and dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (EPOCH-R), patients receiving rituximab, cyclophosphamide, vincristine, doxorubicin, methotrexate/ifosfamide, etoposide, and cytarabine (R-CODOX-M/IVAC) had a non-significant tendency to better overall survival (hazard ratio, 0.37; P=0.10). In conclusion, high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements had heterogeneous outcomes and MYC/IG rearrangements were not associated with inferior overall survival.

Increased MYC copy number is an independent prognostic factor in patients with diffuse large B-cell lymphoma

Patients with double-hit or triple-hit lymphoma have a significantly worse prognosis compared to patients with diffuse large B-cell lymphoma without MYC rearrangement. However, the prognostic importance of extra copies of MYC, BCL2, or BCL6 has not been fully explored. We studied 663 patients with de novo diffuse large B-cell lymphoma in whom the status of MYC/8q24, BCL2/18q21, and BCL6/3q27 were assessed by fluorescence in situ hybridization. Cases of double or triple extra copy lymphoma were defined by the presence of increased MYC copies and increased BCL2 and/or BCL6 copies or rearrangement. In total, 76 patients with diffuse large B-cell lymphoma had MYC extra copies including 43 cases of double or triple extra copy lymphoma; 105 patients had diffuse large B-cell lymphoma with MYC-R including 56 double- or triple-hit lymphoma; and 482 diffuse large B-cell lymphoma patients had no MYC abnormality (MYC normal). Patients with MYC extra copies, similar to MYC-R, had a worse overall survival compared with MYC normal patients (both P<0.01). The prognosis between patients with MYC extra copies and MYC-R was not statistically significantly different (P=0.086). Cell-of-origin classification failed to correlate with survival in the MYC extra copies group, similar to the MYC-R patient group. Compared with patients with double- or triple-hit lymphoma, patients with double or triple extra copy lymphoma had a higher complete remission rate (P=0.02), but there was no significant statistical difference in overall survival (P=0.089). Intensive induction chemotherapy regimens improved the overall survival of patients with double or triple extra copy lymphoma, but there was no significant improvement of overall survival in patients with MYC-R tumors. Multivariate analysis showed that MYC extra copy in diffuse large B-cell lymphoma is an independent poor prognostic factor, similar to MYC rearrangement.

Diffuse large B-cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma worldwide, representing approximately 30-40% of all cases in different geographic regions. Patients most often present with a rapidly growing tumour mass in single or multiple, nodal or extranodal sites. The most common type of DLBCL, designated as not otherwise specified, represents 80-85% of all cases and is the focus of this review. There are also rare types of lymphoma composed of large B-cells, in aggregate about 15-20% of all neoplasms that are sufficiently distinctive to recognise separately. DLBCL not otherwise specified (referred to henceforth as DLBCL) is a heterogeneous entity in terms of clinical presentation, genetic findings, response to therapy, and prognosis. A major advance was the application of gene expression profiling (GEP) to the study of DLBCL which further clarified this heterogeneity and provided a rationale for subdividing cases into groups. The most popular system divides cases of DLBCL according to cell-of-origin into germinal centre B-cell like (GCB) and activated B-cell like (ABC) subtypes, with about 10-15% of cases being unclassifiable. Patients with the GCB subtype usually have better prognosis than patients with the ABC subtype. Although cell-of-origin is useful for predicting outcome, the GCB and ABC subtypes remain heterogeneous, with better and worse prognostic subsets within each group. Next generation sequencing (NGS) analysis of DLBCL has facilitated global identification of numerous and diverse genetic abnormalities in these neoplasms and has shown that GCB and ABC tumours have different mutation profiles. Although the therapy of patients with DLBCL is an active area of research, the current 5-year overall survival rate is 60-70% using standard-of-care frontline therapy. A precision medicine approach for the design of new therapies based on molecular findings in DLBCL is likely the best path forward. As pathologists, our role has expanded beyond diagnosis. We must perform a complete work-up of DLBCL cases. In addition to our traditional role in establishing the diagnosis, we need to analyse markers that provide information regarding prognosis and potential therapeutic targets. We also must ensure that adequate tissue is triaged for molecular studies which are essential for designing therapy regimens, particularly in the setting of disease relapse.

P53 expression correlates with poorer survival and augments the negative prognostic effect of MYC rearrangement, expression or concurrent MYC/BCL2 expression in diffuse large B-cell lymphoma

In patients with diffuse large B-cell lymphoma, MYC rearrangement (MYC-R), MYC expression, or concurrent expression of MYC and BCL2 is associated with a poorer prognosis. P53 expression also has been shown to confer inferior survival in diffuse large B-cell lymphoma patients, but less is known about the role of P53 expression in those with MYC-R, MYC expression (MYC+), or MYC&BCL2 co-expression (MYC+/BCL2+). We studied P53 expression in 201 patients with untreated de novo diffuse large B-cell lymphoma. Sixty-seven (33%) cases were P53 positive, 56 (28%) had MYC-R (including 17 MYC/BCL2 double hit lymphoma), 86 (45%) were MYC+/BCL2+, and 47 (24%) were positive for both MYC and P53. Compared with patients with P53 negative lymphoma, the P53 positive group had a poorer overall survival (P=0.004). In patients with lymphoma harboring MYC-R, MYC expression or MYC+/BCL2+, P53 expression was associated with a significantly worse overall survival (P<0.0001, P=0.01, and P=0.035, respectively). Patients with lymphoma showing concurrent P53 expression and MYC-R had a worse prognosis compared with patients with either P53 expression or MYC-R alone (P<0.0001). Similarly, P53 enhanced the negative prognostic effect of MYC expression in DLBCL patients. In addition, among patients with lymphoma with concurrent MYC and P53 expression, MYC and BCL2 or BCL2 & P53 expression, those patients with tumors with MYC and P53 expression had the worst overall survival (P=0.005), regardless of BCL2 expression status. Multivariate analysis demonstrated that both MYC-R and P53 expression were independent prognostic factors in this patient cohort. In conclusion, our data suggest that P53 expression and MYC -R or MYC expression have an additive negative prognostic effect in diffuse large B-cell lymphoma patients. Assessment of P53 expression adds additional prognostic information in de novo diffuse large B-cell lymphoma patients, especially in subgroups with MYC-R, MYC expression and MYC and BCL2 double expression.