MYC protein expression and genetic alterations have prognostic impact in patients with diffuse large B-cell lymphoma treated with immunochemotherapy

Preclinical development of CD37CAR T-cell therapy for treatment of B-cell lymphoma

T cells modified to express chimeric antigen receptor (CAR) targeting CD19 (CD19CAR) have produced remarkable clinical responses in patients with relapsed/refractory B-cell acute lymphoblastic leukemia. CD19CAR T-cell therapy has also demonstrated prominent effects in B-cell non-Hodgkin lymphoma (B-NHL) patients. However, a subset of patients who relapse after CD19CAR T-cell therapy have outgrowth of CD19^- tumor cells. Hence, development of alternative CARs targeting other B-cell markers represents an unmet medical need for B-cell acute lymphoblastic leukemia and B-NHL. Here, we confirmed previous data by showing that, overall, B-NHL has high expression of CD37. A second-generation CD37CAR was designed, and its efficacy in T cells was compared with that of CD19CAR. In vitro assessment of cytotoxicity and T-cell function upon coculture of the CAR T cells with different target B-cell lymphoma cell lines demonstrated comparable efficacy between the 2 CARs. In an aggressive B-cell lymphoma xenograft model, CD37CAR T cells were as potent as CD19CAR T cells in controlling tumor growth. In a second xenograft model, using U2932 lymphoma cells containing a CD19^- subpopulation, CD37CAR T cells efficiently controlled tumor growth and prolonged survival, whereas CD19CAR T cells had limited effect. We further show that, unlike CD19CAR, CD37CAR was not sensitive to antigen masking. Finally, CD37CAR reactivity was restricted to B-lineage cells. Collectively, our results demonstrated that CD37CAR T cells also can effectively eradicate B-cell lymphoma tumors when CD19 antigen expression is lost and support further clinical testing for patients with relapsed/refractory B-NHL.

Identification of "Double Hit" Lymphomas Using Updated WHO Criteria: Insights From Routine MYC Immunohistochemistry in 272 Consecutive Cases of Aggressive B-Cell Lymphomas

Aggressive lymphomas with MYC and BCL2 and/or BCL6 translocations ("double hit" lymphomas, DHL) represent a distinct diagnostic category in the updated World Health Organization (WHO) classification. The diagnostic yield of MYC immunohistochemistry (IHC) for the identification of DHL is currently uncertain. MYC IHC was performed in 272 consecutive cases of aggressive B-cell lymphoma, and results correlated with fluorescence in situ hybridization (FISH) for MYC translocations. Among 156 patients with IHC and FISH data, MYC IHC identified MYC translocations with 89% sensitivity, 38% specificity, 92% negative predictive value, and 29% positive predictive value. Three of 15 (20%) of DHL were MYC IHC negative. One case contained a MYC translocation detectable IGH/MYC fusion probes but not MYC break-apart probes. A subset of DHL lack MYC protein expression, and recognition of this subset of cases requires FISH testing. These results provide an appropriate diagnostic algorithm for implementation of 2016 WHO diagnostic criteria.

An increase in MYC copy number has a progressive negative prognostic impact in patients with diffuse large B-cell and high-grade lymphoma, who may benefit from intensified treatment regimens

MYC translocations, a hallmark of Burkitt lymphoma, occur in 5-15% of diffuse large B-cell lymphoma, and have a negative prognostic impact. Numerical aberrations of MYC have also been detected in these patients, but their incidence and prognostic role are still controversial. We analyzed the clinical impact of MYC increased copy number on 385 patients with diffuse large B-cell lymphoma screened at diagnosis for MYC, BCL2, and BCL6 rearrangements. We enumerated the number of MYC copies, defining as amplified those cases with an uncountable number of extra-copies. The prevalence of MYC translocation, increased copy number and amplification was 8.8%, 15%, and 1%, respectively. Patients with 3 or 4 gene copies, accounting for more than 60% of patients with MYC copy number changes, had a more favorable outcome compared to patients with >4 copies or translocation of MYC, and were not influenced by the type of treatment received as first-line. Stratification according to the number of MYC extra-copies showed a negative correlation between an increasing number of copies and survival. Patients with >7 copies or the amplification of MYC had the poorest prognosis. Patients with >4 copies of MYC showed a similar, trending towards worse prognosis compared to patients with MYC translocation. The survival of patients with >4 copies, translocation or amplification of MYC seemed to be superior if intensive treatments were used. Our study underlines the importance of fluorescence in situ hybridization testing at diagnosis of diffuse large B-cell lymphoma to detect the rather frequent and clinically significant numerical aberrations of MYC.

Clinical Interest of LMO2 Testing for the Diagnosis of Aggressive Large B-Cell Lymphomas

MYC rearrangements usually confer aggressive biological behavior to large B-cell lymphomas. In this study, we aimed to evaluate the relevance of LMO2 detection to the clinical approach to these tumors. First, the ability of LMO2 loss of expression to recognize the presence of MYC rearrangements was evaluated. A series of 365 samples obtained from 351 patients, including 28 Burkitt lymphoma, 230 diffuse large B-cell lymphoma, 30 high-grade B-cell lymphoma with MYC and BCL2/BCL6 rearrangements, eight high-grade B-cell lymphoma-NOS, 43 transformed diffuse large B-cell lymphoma, and 26 high-grade follicular lymphomas was analyzed. Among the CD10-positive tumors prospectively analyzed in whole tissue sections, LMO2 negative expression obtained values of 88% sensitivity, 94% specificity, and 93% accuracy, proving the utility of LMO2 to screen MYC rearrangements. In addition, survival analyses were performed in a series of 155 patients. As per univariate analyses, the prognosis relevance of LMO2 was as useful as that of the diagnostic categories, MYC rearrangements, and MYC immunohistochemistry. Multivariate models revealed that both LMO2 (hazard ratio 0.51 p = 0.02) and IPI (hazard ratio 1.67 p < 0.005) were independent variables predicting overall survival. Finally, MYC and LMO2 mRNA expression were analyzed in a small group of cases. Taken together, these findings show the interest of LMO2 testing in large B-cell lymphomas.

The Frequency of Double Expresser in Selected Cases of High Grade Diffuse Large B-Cell Lymphomas

Background:

Diffuse large B-cell lymphomas (DLBCL) are fast-growing non-Hodgkin lymphomas that affect B-lymphocytes. Double expressor DLBCL is the concomitant expression of Myc and Bcl-2 proteins during lymphomas which results in poor prognosis of patients. This study aimed to determine the frequency of double expresser in high grade diffuse large B-cell lymphomas.

Materials and Methods :

The study was conducted on 74 cases (54 males (68.4%) and 20 females (25.3%)) of DLBCL between August 2018 to January 2019. The mean age of the 74 patients was 51.7 years + 18.5. Expression of proteins c-Myc, Bcl-2 and Bcl-6 were evaluated by immunohistochemistry. The involvement of primary lymph node was reported in 38 cases (51.3%) whereas, extra nodal site was observed in 22 cases (29.7%). Among the primary sites, the cervical lymph node enlargement was the most frequent site of presentation.

Results:

The rearrangement pattern was studied among 74 patients, 35 (47%) were found to have either one of the rearrangements i.e. Myc, Bcl-2, or Bcl-6. On the other hand, 14 (18.9%) had shown double rearrangements i.e. Bcl-2 and c-Myc (11 cases) and Bcl-6 and c-Myc (3 cases). The Bcl-2 and Bcl-6 rearrangements were demonstrated by 12 cases whereas 2 cases (2.7%) indicated all three types of rearrangements i.e. c-Myc, Bcl-2, and Bcl-6. In 11 cases the Bcl-2 and c-Myc rearrangements were found to be Bcl-2 > 50% and c-Myc > 40% and demonstrating the overall frequency of double expressers as 14.8%. The prognosis of the mentioned cases was extremely poor, median survival of 10 months. Conclusion: The concurrent expression of Bcl-2 and c-Myc was found to be 14% (level of expression for Bcl-2 > 50% and c-Myc > 40%) which is potentially a significant health burden and an emerging threat.

MYC's Fine Line Between B Cell Development and Malignancy

The transcription factor MYC is transiently expressed during B lymphocyte development, and its correct modulation is essential in defined developmental transitions. Although temporary downregulation of MYC is essential at specific points, basal levels of expression are maintained, and its protein levels are not completely silenced until the B cell becomes fully differentiated into a plasma cell or a memory B cell. MYC has been described as a proto-oncogene that is closely involved in many cancers, including leukemia and lymphoma. Aberrant expression of MYC protein in these hematological malignancies results in an uncontrolled rate of proliferation and, thereby, a blockade of the differentiation process. MYC is not activated by mutations in the coding sequence, and, as reviewed here, its overexpression in leukemia and lymphoma is mainly caused by gene amplification, chromosomal translocations, and aberrant regulation of its transcription. This review provides a thorough overview of the role of MYC in the developmental steps of B cells, and of how it performs its essential function in an oncogenic context, highlighting the importance of appropriate MYC regulation circuitry.

The Spectrum of MYC Alterations in Diffuse Large B-Cell Lymphoma

MYC, as a powerful transcription factor, plays a vital role in various cancers. The clinical significance of MYC alterations in diffuse large B-cell lymphoma (DLBCL) has been investigated for a long time. In this study, we comprehensively summarize the different alterations of MYC in DLBCL, including MYC overexpression, MYC translocations, MYC mutations, and increased gene copy number of MYC. Noteworthy, lone MYC overexpression or MYC translocation is not significantly associated with poor clinical outcomes, and their detrimental effects depend on the genetic alterations of BCL2 or BCL6. Both double-expressor DLBCL (DE-DLBCL), defined as overexpression of MYC and BCL2 proteins, and double-hit lymphoma (DHL), defined as a dual translocation of MYC together with BCL2 or BCL6, represent the distinct subgroups of DLBCL with inferior clinical outcomes. The mechanism may be that MYC activation induces cell proliferation, without the threat of the apoptotic brake in the presence of BCL2 overexpression. In addition, most of MYC mutations are present with favorable prognosis, and the nonsignificant effect of MYC copy number amplification has been observed. It has been proved that cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab show limited effects for DHL or DE-DLBCL, and the rituximab plus dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin seem to be efficacious for DHL. The novel therapy is urgently needed for clinical improvement in DHL and DE-DLBCL.

Educational Case: Gastric High-Grade B-Cell Lymphoma With MYC and BCL2 Gene Rearrangement (Double-Hit Lymphoma)

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

High level MYC amplification in B-cell lymphomas: is it a marker of aggressive disease?

While MYC translocations in B-cell lymphoma (BCL) have been extensively studied, the significance of MYC amplification (MYC amp) is poorly understood. This study characterizes BCL showing MYC amp, defined as uncountable FISH signals. Retrospective analysis of all BCL FISH for MYC aberrations performed at our institution (1/2010-2/2018) identified 44/9715 (0.45%) cases with MYC amp. MYC amp probe signals appeared in a cloud-like distribution (70%) or in a single homogenous-staining-region (30%). In total 59% also had MYC separation by breakapart probe indicating concurrent MYC translocation. The most common morphology was large cell (82%) and diagnosis was diffuse large BCL (DLBCL, 50%). In total 88% were germinal center B-cell-like by Hans algorithm. In total 12/42 (29%) cases were "double-hit" by WHO criteria (DHL/THL) in addition to having MYC amp. The estimated 2-year overall survival (OS) of DLBCL cases with MYC amp was 80%. There was no significant difference in OS between DLBCL and DHL/THL among cases with MYC amp, suggesting a poor prognostic impact of MYC amp. However, when compared to a larger cohort of DLBCL and DHL/THL, MYC amp did not have prognostic significance. In summary, MYC amp in BCL is rare, most commonly occurs in DLBCL, and was not associated with survival in our cohort.

MYC in Germinal Center-derived lymphomas: Mechanisms and therapeutic opportunities

The rearrangement of immunoglobulin loci during the germinal center reaction is associated with an increased risk of chromosomal translocations that activate oncogenes such as MYC, BCL2 or BCL6, thus contributing to the development of B-cell lymphomas. MYC and BCL2 activation are initiating events in Burkitt's (BL) and Follicular Lymphoma (FL), respectively, but can occur at later stages in other subtypes such as Diffuse Large-B Cell Lymphoma (DLBCL). MYC can also be activated during the progression of FL to the transformed stage. Thus, either DLBCL or FL can give rise to aggressive double-hit lymphomas (DHL) with concurrent activation of MYC and BCL2. Research over the last three decades has improved our understanding of the functions of these oncogenes and the basis for their cooperative action in lymphomagenesis. MYC, in particular, is a transcription factor that contributes to cell activation, growth and proliferation, while concomitantly sensitizing cells to apoptosis, the latter being blocked by BCL2. Here, we review our current knowledge about the role of MYC in germinal center B-cells and lymphomas, discuss MYC-induced dependencies that can sensitize cancer cells to select pharmacological inhibitors, and illustrate their therapeutic potential in aggressive lymphomas-and in particular in DHL, in combination with BCL2 inhibitors.

Rs4846049 Polymorphism at the 3'-UTR of MTHFR Gene: Association with Susceptibility to Childhood Acute Lymphoblastic Leukemia

Background

Accumulating evidence has suggested the polymorphisms of methylenetetrahydrofolate reductase (MTHFR) were associated with susceptibility to childhood acute lymphoblastic leukemia (ALL). However, the known conclusions of currently known polymorphic loci (677 C > T and 1298 A > C) remain controversial. This study was to investigate new genetic biomarkers for ALL by analyzing the MTHFR polymorphisms at the 3′-untranslated region, which is a location bound by miRNAs.

Methods

Polymorphisms of rs4846049 (miR-555 binding) were assessed by PCR amplification and direct sequencing in 110 ALL patients and 105 healthy controls. The relative expression of MTHFR was detected by qRT-PCR.

Results

Overall, genotype distribution or allele carrier frequencies were not significantly different between patients with ALL and healthy controls (P > 0.05). Subgroup analysis results showed that T allele (OR = 0.134, 95% CI = 0.028–0.639; P=0.005) or genotypes with T allele (TT + GT) (OR = 0.133, 95% CI: 0.024–0.727; P=0.017) may be a protective factor for ALL susceptibility in patients with age >8 years. This conclusion was also true for the group only focusing on the precursor B-cell ALL patients. Furthermore, karyotype abnormality was more commonly observed in patients with the GG genotype (56.0%) compared to carriers of TT (0%) or GT (40.6%) genotypes, while c-myc break frequency was significantly higher in TT carriers (33%) than that of patients with GT (3.1%) or GG (0%) genotypes. PCR analysis showed patients carrying the GG genotype of rs4846049 exhibited the reduced mRNA expression of MTHFR.

Conclusion

MTHFR rs4846049 polymorphism may be associated with increased risk of childhood with ALL and MTHFR mRNA expression.

CD5+MYC+ predicts worse prognosis in diffuse large B-cell lymphoma

The dual expression of CD5 and MYC protein (DECM) on B-lymphocytes may arise at a specific stage of de novo diffuse large B-cell lymphoma (DLBCL). This study retrospectively reviewed 210 patients with de novo DLBCL at the Affiliated Hospital of Jiangnan University between 2006 and 2017. DECM was significantly correlated with a worse prognosis than that in either the CD5⁺ or MYC⁺ or CD5^-MYC^- patients. Furthermore, patients with DECM showed a similar outcome to MYC⁺BCL2⁺ lymphoma patients who have extremely poor survival rates. Multivariate analysis demonstrated that DECM was a significant independent predictor for overall survival (P < .0001) and progression-free survival (P < .0001) in DLBCL. DLBCL patients with DECM showed significantly inferior clinical outcomes compared to the CD5⁺, MYC⁺ or CD5^-MYC^- patients. Combinational therapeutic modalities might be a candidate approach to improve the prognosis of these patients.

Germinal Centre B Cell Functions and Lymphomagenesis: Circuits Involving MYC and MicroRNAs

BACKGROUND

The transcription factor MYC regulates several biological cellular processes, and its target gene network comprises approximately 15% of all human genes, including microRNAs (miRNAs), that also contribute to MYC regulatory activity. Although miRNAs are emerging as key regulators of immune functions, the specific roles of miRNAs in the regulation/dysregulation of germinal centre B-cells and B-cell lymphomas are still being uncovered. The regulatory network that integrates MYC, target genes and miRNAs is a field of intense study, highlighting potential pathways to be explored in the context of future clinical approaches.

METHODS

The scientific literature that is indexed in PUBMED was consulted for publications involving MYC and miRNAs with validated bioinformatics analyses or experimental protocols. Additionally, seminal studies on germinal centre B-cell functions and lymphomagenesis were reported.

CONCLUSIONS

This review summarizes the interactions between MYC and miRNAs through regulatory loops and circuits involving target genes in germinal centre B-cell lymphomas with MYC alterations. Moreover, we provide an overview of the understanding of the regulatory networks between MYC and miRNAs, highlighting the potential implication of this approach for the comprehension of germinal centre B-cell lymphoma pathogenesis. Therefore, circuits involving MYC, target genes and miRNAs provide novel insight into lymphomagenesis that could be useful for new improved therapeutic strategies.

Clinical significance of 'double-hit' and 'double-expression' lymphomas

BACKGROUND

'Double-hit' lymphoma (DHL) and 'double-expression' lymphoma (DEL) involving gene rearrangement and protein expression of MYC and BCL2/BCL6 have recently become the most commonly used terms to describe the poor prognostic types of diffuse large B-cell lymphoma (DLBCL). However, the clinical and pathological spectra of these rare entities have not been well defined. The aim of this study was to determine the frequency of DHL and DEL in DLBCL and their prognostic impacts in the era of cyclophosphamide, doxorubicin, vincristine and prednisone plus rituximab therapy.

METHODS

The data and tissues from 98 patients diagnosed with DLBCL were used in this study. Formalin-fixed and paraffin-embedded tissues were constructed for immunohistochemistry (IHC) and interphase fluorescene in situ hybridisation (FISH) analysis for MYC, BCL6 and BCL2 rearrangements.

RESULTS

There were 14 cases (14.29%, 14/98) and 34 cases (34.70%, 34/98) of lymphomas with the DHL and DEL of MYC and BCL2/BCL6, respectively. DLBCL patients with MYC/BCL2 rearrangements more frequently had bone marrow involvement (p=0.002), and their tumours were commonly of the germinal centre B cell (GCB) subtype. Patients with MYC+/BCL2 +coexpression were more often assessed using the International Prognostic Index (IPI), (Performance Status) PS score and bone marrow involvement. Patients with MYC+/BCL6 +coexpression were associated with their IPI values, Eastern Cooperative Oncology Group scores and occurrence of B symptoms. Their lymphomas were more often of the non-GCB subtype (p=0.010). Multivariate analysis showed that IPI, bone marrow involvement, rearrangements of BCL2, BCL6 and MYC, expression concurrent with rearrangements and coexpression were all significantly associated with overall survival and progression-free survival, with the exception of MYC+/BCL6 +coexpression.

CONCLUSIONS

MYC/BCL2 DHL, MYC/BCL6 DHL and MYC/BCL2 DEL are an aggressive B cell lymphoma and patients have a poor prognosis. IPI and bone marrow involvement were independent prognostic factors for DHL and DEL. BCL2, BCL6 and MYC rearrangements translocation, expression concurrent rearrangements and coexpression were were independent prognostic factors for survival.

POTENTIAL IMPLICATIONS

The present study analysed the genomic alterations and protein expression levels of MYC, BCL2 and BCL6 using FISH and IHC in Chinese patients with DLBCL.We assessed the frequency, clinicopathological features and the prognostic impacts of DHL and DEL in a cohort of de novo DLBCL patients and evaluated the role of each genetic translocation separately and in combination in order to provide reliable conclusions and practical recommendations for diagnostic workups and prognostic predictions.

Prognostic Significance of MYC Rearrangement and Translocation Partner in Diffuse Large B-Cell Lymphoma: A Study by the Lunenburg Lymphoma Biomarker Consortium

PURPOSE

MYC rearrangement (MYC-R) occurs in approximately 10% of diffuse large B-cell lymphomas (DLBCLs) and has been associated with poor prognosis in many studies. The impact of MYC-R on prognosis may be influenced by the MYC partner gene (immunoglobulin [IG] or a non-IG gene). We evaluated a large cohort of patients through the Lunenburg Lymphoma Biomarker Consortium to validate the prognostic significance of MYC-R (single-, double-, and triple-hit status) in DLBCL within the context of the MYC partner gene.

METHODS

The study cohort included patients with histologically confirmed DLBCL morphology derived from large prospective trials and patient registries in Europe and North America who were uniformly treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone therapy or the like. Fluorescence in situ hybridization for the MYC, BCL2, BCL6, and IG heavy and light chain loci was used, and results were correlated with clinical outcomes.

RESULTS

A total of 5,117 patients were identified of whom 2,383 (47%) had biopsy material available to assess for MYC-R. MYC-R was present in 264 (11%) of 2,383 patients and was associated with a significantly shorter progression-free and overall survival, with a strong time-dependent effect within the first 24 months after diagnosis. The adverse prognostic impact of MYC-R was only evident in patients with a concurrent rearrangement of BCL2 and/or BCL6 and an IG partner (hazard ratio, 2.4; 95% CI, 1.6 to 3.6; P < .001).

CONCLUSION

The negative prognostic impact of MYC-R in DLBCL is largely observed in patients with MYC double hit/triple-hit disease in which MYC is translocated to an IG partner, and this effect is restricted to the first 2 years after diagnosis. Our results suggest that diagnostic strategies should be adopted to identify this high-risk cohort, and risk-adjusted therapeutic approaches should be refined further.

A combination of LMO2 negative and CD38 positive is useful for the diagnosis of Burkitt lymphoma

Background

To evaluate the clinical utility of LIM Domain Only 2 (LMO2) negative and CD38 positive in diagnosis of Burkitt lymphoma (BL).

Methods

LMO2 and CD38 expression determined by immunohistochemistry in 75 BL, 12 High-grade B-cell lymphoma, NOS (HGBL,NOS) and 3 Burkitt-like lymphomas with the 11q aberration.

Results

The sensitivity and specificity of LMO2 negative for detecting BL were 98.67 and 100%, respectively; those of CD38 positive were 98.67 and 66.67%, respectively. The sensitivity and specificity of a combination of both for detecting BL were 97.33 and 100%, respectively. In our study, the combined LMO2 negative and CD38 positive results had a higher area under the curve than either LMO2 negative or CD38 positive alone.

Conclusions

A combination of LMO2 negative and CD38 positive is useful for the diagnosis of Burkitt lymphoma.

The impact of BCL-2/MYC protein expression and gene abnormality on primary central nervous system diffuse large B-cell lymphoma

We determined the effects of the BCL-2, C-MYC, and BCL-6 gene aberrations and their protein expressions on the prognosis of primary central nervous system diffuse B-cell lymphoma (PCNS-DLBCL) patients. The pathological and clinical information of 47 immunocompetent patients was reviewed, and the immunohistochemical markers for BCL2, CD10, BCL6, MUM1, and MYC were reevaluated. Genetic abnormalities included increased copy number, translocation, gene amplification, and double aberration and were detected by fluorescence in situ hybridization (FISH). A survival analysis showed that elevated protein levels in the cerebrospinal fluid (CSF), increased the IPI score, and EBV infection adversely affected survival. However, high BCL2 (≥70%) and positive MYC expressions (≥40%) showed no significant influence on survival or BCL-2 gene abnormality, and BCL2/MYC double expression and BCL-2/C-MYC double aberrations were associated with adverse outcomes for PCNS-DLBCL patients.

Rare cases of primary central nervous system anaplastic variant of diffuse large B-cell lymphoma

BACKGROUND

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) is a rare intracranial tumor, defined as DLBCL arising from the brain, spinal cord, leptomeninges and eye, with an overall annual incidence of 5 cases per million. The primary CNS anaplastic variant of DLBCL (A-DLBCL) is even less common; to our knowledge, there are only two other case reports in the literature. The aim of this report is to present rare cases of primary CNS A-DLBCL and study their clinicopathologic and genetic features.

CASE PRESENTATION

We report 3 patients, two men and one woman, aged 54, 55 and 67 years old, with primary CNS A-DLBCL. All 3 patients had a high International Extranodal Lymphoma Study Group (IELSG) score; although the patients were treated with methotrexate-based regimens and/or with radiation therapy, the overall survival was only 2, 5, and 8 months. All 3 patients presented with characteristic features of perivascular space infiltration with bizarre-shaped tumor cells, leading to the diagnosis of primary CNS A-DLBCL. Concurrent of MYC and BCL2 and/or BCL6 abnormalities and MYC/BCL2 double-expressor DLBCL occurred in all 3 patients; two patients had MYC/BCL2/BCL6 triple extra copies, and one patient had MYC extra copy and BCL6 translocation. All 3 patients displayed mutations in MYD88 L265P and nuclear positivity for RELA, RELB and/or c-Rel, indicating constitutive activation of the NF-κB pathway.

CONCLUSIONS

These cases shed light on the unique genetic alterations and biological features of primary CNS A-DLBCL. Patients with primary CNS A-DLBCL may often have a MYC/BCL2 double-expressor and concurrent MYC and BCL2 and/or BCL6 genetic abnormalities, as well as constitutive activation of the NF-κB pathway. Primary CNS A-DLBCL follows a very aggressive disease course and poor prognosis. In the future, a large number of cases should be analyzed, and the evaluation of molecular genetic characteristics could help with practical and therapeutic implications for primary CNS A-DLBCL.

Tumour necrosis as assessed with 18F-FDG PET is a potential prognostic marker in diffuse large B cell lymphoma independent of MYC rearrangements

Objectives

MYC gene rearrangements in diffuse large B cell lymphomas (DLBCLs) result in high proliferation rates and are associated with a poor prognosis. Strong proliferation is associated with high metabolic demand and tumour necrosis. The aim of this study was to investigate differences in the presence of necrosis and semiquantitative ¹⁸F-FDG PET metrics between DLBCL cases with or without a MYC rearrangement. The prognostic impact of necrosis and semiquantitative ¹⁸F-FDG PET parameters was investigated in an explorative survival analysis.

Methods

Fluorescence in situ hybridisation analysis for MYC rearrangements, visual assesment, semiquantitative analysis of ¹⁸F-FDG PET scans and patient survival analysis were performed in 61 DLBCL patients, treated at a single referral hospital between 2008 and 2015.

Results

Of 61 tumours, 21 (34%) had a MYC rearrangement (MYC⁺). MYC status was neither associated with the presence of necrosis on ¹⁸F-FDG PET scans (necrosis^PET; p = 1.0) nor associated with the investigated semiquantitative parameters maximum standard uptake value (SUV_max; p = 0.43), single highest SUV_max (p = 0.49), metabolic active tumour volume (MATV; p = 0.68) or total lesion glycolysis (TLG; p = 0.62). A multivariate patient survival analysis of the entire cohort showed necrosis^PET as an independent prognostic marker for disease-specific survival (DSS) (HR = 13.9; 95% CI 3.0–65; p = 0.001).

Conclusions

MYC rearrangements in DLBCL have no influence on the visual parameter necrosis^PET or the semi-quantiative parameters SUV_max, MATV and TLG. Irrespective of MYC rearrangements, necrosis^PET is an independent, adverse prognostic factor for DSS.

Key Points

• Retrospective analysis indicates that MYC rearrangement is not associated with necrosis on¹⁸F-FDG PET (necrosis^PET) scans or semiquantitative¹⁸F-FDG PET parameters.

• Necrosis^PETis a potential independent adverse prognostic factor for disease-specific survival in patients with DLBCL and is not influenced by the presence of MYC rearrangements.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06178-9) contains supplementary material, which is available to authorized users.

Venetoclax plus R- or G-CHOP in non-Hodgkin lymphoma: results from the CAVALLI phase 1b trial

Novel strategies, such as chemosensitization with targeted agents, that build on the success of standard immunochemotherapy show promise for the treatment of non-Hodgkin lymphoma (NHL). Here, we report a phase 1b study investigating dose escalation of the BCL2 inhibitor, venetoclax, in combination with rituximab or obinutuzumab and cyclophosphamide, doxorubicin, vincristine, and prednisone (R-/G-CHOP) chemotherapy in B-cell NHL. Objectives included safety assessment and determination of a recommended phase 2 dose (RP2D). Fifty-six patients were enrolled, most with follicular lymphoma (43%) or diffuse large B-cell lymphoma (DLBCL; 32%). Dose-limiting toxicities were reported in 3/14 patients at the first venetoclax dose (200 mg/d), after which dosing was changed from daily to 10 days per cycle and escalated to 800 mg. A further reduction to 5 days per cycle occurred at the 800-mg dose level in the G-CHOP arm. Cytopenias were predominant among grade 3/4 events and reported at a higher rate than expected, particularly in the G-CHOP arm; however, safety was manageable. Overall response rates were 87.5% (R-CHOP and G-CHOP combinations); complete response (CR) rates were 79.2% and 78.1%, respectively. Most double-expressor (BCL2⁺ and MYC⁺) DLBCL patients (87.5%; n = 7/8) achieved CR. Although the maximum tolerated dose was not reached, the RP2D for venetoclax with R-CHOP was established at 800 mg days 4 to 10 of cycle 1 and days 1 to 10 of cycles 2 to 8; higher doses were not explored, and this dosing schedule demonstrated an acceptable safety profile. This regimen is subsequently being evaluated in first-line DLBCL in the phase 2 portion of the study. This trial was registered at www.clinicaltrials.gov as #NCT02055820.

Correlation Between C-MYC, BCL-2, and BCL-6 Protein Expression and Gene Translocation as Biomarkers in Diagnosis and Prognosis of Diffuse Large B-cell Lymphoma

This study investigates the protein expression of C-MYC, BCL-2, and BCL-6 in diffuse large B-cell lymphoma (DLBCL) and their relationship with genetic abnormalities. A retrospective study of 42 cases on paraffin-embedded tissue specimens diagnosed with DLBCL was performed using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). The expression of C-MYC, BCL-2, BCL-6 protein, and gene abnormalities in these tissue samples was analyzed. The relationship in genetic abnormalities and Ki-67, Hans classification, gender, and age was also evaluated. It was found that the positive rate of C-MYC expression was 47.6% (20/42), the rate of C-MYC gene abnormality was 26.2% (11/42), in which gene translocation accounted for 23.8% (10/42) and gene amplification 2.4% (1/42); C-MYC protein expression was positively correlated with C-MYC gene translocation (χ2 = 11.813; P = 0.001); C-MYC gene translocation was mainly found in germinal center B cell type (χ2 = 4.029; P = 0.045). The positive rate of BCL-2 protein expression was 85.71% (36/42), the positive rate of translocation was 42.86% (18/42) and the amplification rate was 26.19% (11/42); the overexpression of BCL-2 protein was correlated with the BCL-2 translocation (χ2 = 3.407; P = 0.029). The positive rate of BCL-6 protein expression was 45.24% (19/42), the positive rate of BCL-6 translocation was 14.29% (6/42) and the positive rate of BCL-6 amplification was 7.14% (3/42); the overexpression of BCL-6 protein was significantly correlated with BCL-6 translocation (χ2 = 6.091; P = 0.014). The Ki-67 index was significantly higher in C-MYC translocation cases than in non-C-MYC translocation cases (χ2 = 4.492; P = 0.034). Taken together, our results suggest that the protein expression of C-MYC, BCL-2, and BCL-6 are positively correlated with their gene translocation. Overexpression of C-MYC, BCL-2, BCL-6 protein suggests the possibility of translocation. Therefore, immunohistochemical detection of C-MYC, BCL-2, and BCL-6 are useful in diagnosis and prognosis of DLBCL.

Clinical Significance of BCL2, C-MYC, and BCL6 Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients

Background: Clinical significance of germinal center B-cell (GCB) and non-GCB sub-categorization, expression of MYC, BCL2, BCL6, CD5 proteins and Epstein Barr virus encoded RNA (EBER) positivity in diffuse large B-cell lymphoma (DLBCL) remain controversial. Could these biomarkers accurately identify high risk DLBCL patients? Are MYC, BCL2 and BCL6 proteins expression feasible as baseline testing to predict c-Myc, BCL2 or BCL6 gene rearrangements? Aims: To investigate prognostic values of GCB/non-GCB sub-categorization, Double Protein Expression Lymphoma (DPL), Triple Protein Expression Lymphoma (TPL), positivity of CD5 protein and EBER in patients with DLBCL disease. To evaluate correlation between BCL2 , c-Myc and BCL6 gene rearrangements with BCL2, MYC and BCL6 proteins expression. Methods: Diagnostic tissue samples of 120 DLBCL patients between January 2012 to December 2013 from four major hospitals in Malaysia were selected. Samples were subjected to immunohistochemical staining, fluorescent in-situ hybridization (FISH) testing, and central pathological review. Pathological data were correlated with clinical characteristics and treatment outcome. Results: A total of 120 cases were analysed. Mean age of diagnosis was 54.1 years ± 14.6, 64 were males, 56 were females, mean follow up period was 25 months (ranged from 1 to 36 months). Of the 120 cases, 74.2% were non-GCB whereas 25.8% were GCB, 6.7% were EBER positive, 6.7% expressed CD5 protein, 13.3% were DPL and 40% were TPL. The prevalence of c-Myc, BCL2, BCL6 gene rearrangements were 5.8%, 5.8%, and 14.2%, respectively; and 1.6% were Double Hit Lymphoma (DHL). EBER positivity, DPL, TPL, c-Myc gene rearrangement, BCL2 gene rearrangement, extra copies of BCL2 gene and BCL6 gene rearrangement were associated with shorter median overall survival (P<0.05). IPI score was the significant determinants of median overall survival in DPL and TPL (P<0.05). CD5 protein expression and GCB/non-GCB sub-categorization did not affect treatment outcome (P>0.05). Overall, c-Myc, BCL2 and BCL6 gene rearrangements showed weak correlation with expression of MYC, BCL2 and BCL6 proteins (P>0.05). Fluorescent in situ hybridization is the preferred technique for prediction of treatment outcome in DLBCL patients. Conclusion: c-Myc, BCL2, and BCL6 gene rearrangements, EBER expression, DHL, TPL and IPI score are reliable risk stratification tools. MYC, BCL2 and BCL6 proteins expression are not applicable as baseline biomarkers to predict c-Myc, BCL2, and BCL6 gene rearrangements.

Genomics of aggressive B-cell lymphoma

The growing body of genomic information collected and applied to mature aggressive B-cell lymphoma diagnosis and management has exploded over the last few years due to improved technologies with high-throughput capacity, suitable for use on routine formalin-fixed, paraffin-embedded tissue biopsies, and decreasing costs. These techniques have made evaluation of complete DNA sequences, RNA-expression patterns, translocations, copy-number alterations, loss of heterozygosity, and DNA-methylation patterns possible on a genome-wide level. This chapter will present a case of aggressive B-cell lymphoma and discuss the most important genomic abnormalities that characterize this group of entities in the recent update to the fourth edition of the World Health Organization (WHO) lymphoma classification system. Genomic abnormalities discussed will include those necessary for certain diagnoses such as translocations of MYC, BCL2, or BCL6; gene-expression-profiling categorization; the newly defined Burkitt-like lymphoma with 11q abnormalities; prognostic and predictive mutations, as well as tumor heterogeneity. Finally, our current practices for clinical triage of specimens with a potential diagnosis of aggressive B-cell lymphomas are also described. Options for treatment at relapse, in light of these genomic features, will be discussed in the third presentation from this session.

Immunohistochemical pattern of c-MYC protein judged as "+/(weak)+/-" by a new notation correlates with MYC gene nontranslocation in large B-cell lymphoma

Immunohistochemistry is not only the most important tool for pathologists to establish a final diagnosis, but it can also inform decisions regarding optimal treatment methods. However, there is no universal standard notation for expressing immunohistochemical findings. For a diagnosis of malignant lymphoma, it is important to confirm the presence or absence of MYC translocation and communicate these results to a clinical audience. However, the criteria for selecting cases for fluorescence in situ hybridization (FISH) analysis to confirm MYC translocation are ill defined. We therefore devised a notation that we termed proportion of immunoreactivity/expression for immunohistochemistry (PRIME notation) based on the cellular proportion showing different antigen-antibody reactivity in immunohistochemistry (CPAR) and used it to examine the relationship between MYC translocation and the proportion of c-MYC+ lymphoma cells. We reviewed 82 cases diagnosed as diffuse large B-cell lymphoma or diffuse large B-cell lymphoma coexisting with grade 3A to 3B follicular lymphoma. The most common notation was "+/(weak)+/-" (49/82 cases [59.8%]); cases that were CPAR positive, weakly positive, and negative for tumor cells each accounted for about one-third of the total. Unexpectedly, no MYC translocation was observed by FISH in this group. Thus, FISH is not needed even if more than half of cells are c-MYC positive by PRIME notation. This is the first report describing a correspondence between immunohistochemical findings and chromosomal abnormality, reflecting findings at the protein and gene levels, respectively.

TIRAP p.R81C is a novel lymphoma risk variant which enhances cell proliferation via NF-κB mediated signaling in B-cells

Diffuse large B-cell lymphoma is the most common malignant lymphoma in adults. By gene-expression profiling, this lymphoma is divided in three cell-of-origin subtypes with distinct molecular and clinical features. Most lymphomas arise sporadically, yet familial clustering is known, suggesting a genetic contribution to disease risk. Familial lymphoma cases are a valuable tool to investigate risk genes. We studied a Swiss/Japanese family with 2 sisters affected by a primary mediastinal B-cell lymphoma and a non-germinal center diffuse large B-cell lymphoma not otherwise specified, respectively. The somatic landscape of both lymphomas was marked by alterations affecting multiple components of the JAK-STAT pathway. Consequently, this pathway was constitutively activated as evidenced by high pJAK2 as well as increased nuclear pSTAT3 and pSTAT6 in malignant cells. Potential lymphoma risk variants were identified by whole exome sequencing of the germline DNA derived from siblings and unaffected family members. This analysis revealed a pathogenic variant in TIRAP, an upstream regulator of NF-κB, in both affected siblings and their mother. We observed increased B-cell proliferation in family members harboring the TIRAP p.R81C variant. B-cell proliferation correlated with TIRAP and NF-κB target gene expression, suggesting enhanced NF-κB pathway activity in TIRAP p.R81C individuals. TIRAP knockdown reduced B-cell survival and NF-κB target gene expression, particularly in individuals with TIRAP p.R81C. Functional studies revealed significantly increased NF-κB activity and resistance to stress-induced cell-death by TIRAP p.R81C. The identification of an inherited TIRAP variant provides evidence for a novel link between genetic alterations affecting the NF-κB pathway and lymphomagenesis.

Double hit and double expressors in lymphoma: Definition and treatment

Emerging biologic subsets and new prognostic markers are significantly and adversely affecting curability after standard chemoimmunotherapy for aggressive B-cell lymphomas. The identification of concurrent MYC and B-cell CLL/lymphoma 2 (BCL2) deregulation, whether at a genomic or protein level, has opened a new era of investigation within the most common subtype of aggressive B-cell lymphomas. Double-hit lymphoma (DHL), defined as a dual rearrangement of MYC and BCL2 and/or B-cell CLL/lymphoma 6 (BCL6) genes, is an uncommon subset accounting for 5% to 7% of all diffuse large B-cell lymphomas (DLBCLs), and long-term survivors are rare. Double-expressor lymphoma (DEL), defined as overexpression of MYC and BCL2 proteins not related to underlying chromosomal rearrangements, is not a distinct entity in the current World Health Organization classification but accounts for 20% to 30% of DLBCL cases and also has poor outcomes. There are many practical considerations related to identifying, determining the prognosis of, and managing DHL and DEL.

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.

Comparison of evaluation techniques, including digital image analysis, for MYC protein expression by immunohistochemical stain in aggressive B-cell lymphomas

Incorporation of an MYC immunohistochemical stain in the workup of large B-cell lymphomas has become common in hematopathology practice. Evaluation of this stain can be difficult because of staining heterogeneity and can have interobserver variability, particularly when performed on the entire tumor sections. We identified 87 cases of aggressive B-cell lymphoma (34 core needle and 53 excisional biopsies) and compared the following methods of MYC immunohistochemical staining evaluation: the original pathologist's interpretation, a systematic retrospective method of evaluation by manual analysis, and a retrospective method of evaluation by digital image analysis (using scanned slides analyzed via the Aperio Nuclear algorithm). Overall, concordance among these methods was around 80% with κ statistics showing good agreement. However, nearly one-third of our cases had a percent MYC positivity in the 30% to 50% range, and for these cases, concordance among the various methods was marginal/poor. This suggests limited utility as a prognostic or predictive marker using 40% as a cutoff value. In our series, core biopsy specimens were poor predictors of MYC gene rearrangement, and there was no association between MYC immunohistochemical stain and MYC gene gain/amplification. Our retrospective digital image analysis showed strong correlation in MYC percent positivity with our retrospective manual review (correlation coefficient of 0.90) and similar concordance to pathologist interpretation as among pathologists, suggesting that digital image analysis is a viable alternative to manual determination of MYC percent positivity. Digital image analysis provides further opportunities for more sophisticated and standardized scoring systems, which may be helpful in future prognostic/predictive studies.

Angelica gigas Nakai and Decursin Downregulate Myc Expression to Promote Cell Death in B-cell Lymphoma

Angelica gigas Nakai (AGN) is an oriental traditional medicine to treat anemia, dysmenorrhea, and migraine. However, its anti-lymphoma effect is yet to be tested. Here, we demonstrated that AGN and its major component decursin target Myc to suppress lymphomagenesis in vitro and in vivo. AGN inhibited cell viability in multiple B lymphoma cells, while sparing normal splenocytes and bone marrow cells. Increased cleaved PARP level and caspase 3/7 activity and the repression of survival-promoting AKT/mTOR and MAPK pathways downstream of BCR, were responsible for the pro-apoptotic effects of AGN. We found that Myc, a prominent downstream target of these signaling pathways, contributes to AGN-induced cell death. Moreover, co-treatment with AGN and a Myc inhibitor, JQ1 or 10058-F4 yielded synergistic cytotoxic activities against cancer cells with markedly reduced Myc expression. AGN downregulated Myc expression and suppressed tumorigenesis in Eμ-myc transgenic mice. The proapoptotic activities of AGN were recapitulated by decursin, indicating that the anti-tumor effect of AGN was mainly caused by decursin. These findings suggest that AGN and decursin possess potent anti-lymphoma activity, and combination therapies with AGN/decursin and a Myc inhibitor to target Myc more efficiently could be a valuable avenue to explore in the treatment of B-cell lymphoma.

Pharmacological modulation of CXCR4 cooperates with BET bromodomain inhibition in diffuse large B-cell lymphoma

Constitutive activation of the chemokine receptor CXCR4 has been associated with tumor progression, invasion, and chemotherapy resistance in different cancer subtypes. Although the CXCR4 pathway has recently been suggested as an adverse prognostic marker in diffuse large B-cell lymphoma, its biological relevance in this disease remains underexplored. In a homogeneous set of 52 biopsies from patients, an antibody-based cytokine array showed that tissue levels of CXCL12 correlated with high microvessel density and bone marrow involvement at diagnosis, supporting a role for the CXCL12-CXCR4 axis in disease progression. We then identified the tetra-amine IQS-01.01RS as a potent inverse agonist of the receptor, preventing CXCL12-mediated chemotaxis and triggering apoptosis in a panel of 18 cell lines and primary cultures, with superior mobilizing properties in vivo than those of the standard agent. IQS-01.01RS activity was associated with downregulation of p-AKT, p-ERK1/2 and destabilization of MYC, allowing a synergistic interaction with the bromodomain and extra-terminal domain inhibitor, CPI203. In a xenotransplant model of diffuse large B-cell lymphoma, the combination of IQS-01.01RS and CPI203 decreased tumor burden through MYC and p-AKT downregulation, and enhanced the induction of apoptosis. Thus, our results point out an emerging role of CXCL12-CXCR4 in the pathogenesis of diffuse large B-cell lymphoma and support the simultaneous targeting of CXCR4 and bromodomain proteins as a promising, rationale-based strategy for the treatment of this disease.

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.

A multicolour flow cytometric assay for c-MYC protein in B-cell lymphoma

AIM

Develop an objective assay to detect c-MYC protein expression using multiparametric flow cytometry (FCM) as an alternative to immunohistochemistry (IHC).

METHODS

57 patient samples and 11 cell line samples were evaluated. Cell suspensions were obtained and c-MYC staining was performed in combination with CD45 and CD19 and, in some samples, CD10. The percentage of c-MYC+ cells by FCM was correlated with the percentage determined by IHC. The relationship between c-MYC protein expression and the presence of a c-MYC gene rearrangement in aggressive and high-grade lymphomas was also assessed.

RESULTS

c-MYC expression by FCM and IHC demonstrated a high degree of correlation in a training set of 33 patient cases, r=0.92, 11 cell line samples, r=0.81 and in a validation set of 24 aggressive and high-grade B-cell lymphomas, r=0.85. c-MYC gene was rearranged by fluorescence in situ hybridisation in 6/9 samples with high c-MYC expression (>40%) by FCM and 6/14 by IHC.

CONCLUSIONS

We have developed a reliable multicolour FCM assay to detect c-MYC expression suitable for clinical laboratories that should be helpful to accurately quantify c-MYC expression in B-cell lymphomas.

Unexpected favorable outcome in a patient with high grade B-cell lymphoma with abnormalities of MYC, BCL6 and BCL2 loci

High grade B-cell lymphoma (HGBCL) by WHO 2016 classification requires rearrangements of MYC and BCL2 and/or BCL6, practically covering the so called "double-hit" or "triple hit" lymphomas. We report a case of HGBCL "triple-hit" lymphoma in a 64-year old female. Cytogenetic and fluorescence in situ hybridization (FISH) studies revealed complex karyotype including rearrangement of MYC to a novel, non-IG partner on chromosome 18, and rearrangement of BCL2, BCL6 and IGH as well as ins(3)(q21q27.3q25.1) among other abnormalities. FISH studies showed five copies of MYC and 3-8 copies of BCL2. Gene expression analysis by RNA sequencing showed that MYC, BCL2 and MECOM genes were overexpressed whereas BCL6 was under-expressed. BCL6 was fused to MBNL1 gene due to complex structural rearrangement. MYC was expressed in >70% of cells and BCL2 was diffusely but highly expressed by immunohistochemistry. No pathogenic mutations were identified by sequencing a 26-gene panel including TP53. The patient has unexpectedly been in complete remission for 12 months after diagnosis after intensive chemotherapy including DA-EPOCH regimen despite having HGBCL. The prognostication of HGBCL patients may further be improved by the sub-categorization of these lymphomas on the basis of more detailed genomic markers than merely the WHO 2016 classification.

Concordant bone marrow involvement of diffuse large B-cell lymphoma represents a distinct clinical and biological entity in the era of immunotherapy

In diffuse large B-cell lymphoma (DLBCL), the clinical and biological significance of concordant and discordant bone marrow (BM) involvement have not been well investigated. We evaluated 712 de novo DLBCL patients with front-line rituximab-containing treatment, including 263 patients with positive and 449 with negative BM status. Compared with negative BM disease, concordant BM adversely impacted overall and progression-free survival, independent of the International Prognostic Index (IPI) and cell-of-origin classification. Once BM is concordantly involved, poor prognosis was not associated with the extent of BM involvement. Conversely, patients with discordant BM showed favorable overall survival similar to stage I-II DLBCL. A BM-adjusted IPI, using three parameters: concordant BM involvement, age >60 years, and performance status >1, improves the risk stratification for DLBCL with positive BM. Intensive immunochemotherapy seemingly rendered survival benefit for patients with concordant BM, as did rituximab maintenance for the discordant BM group. Frequently revealing adverse clinical and molecular characteristics, patients with concordant BM demonstrated gene expression signatures relevant to tumor cell proliferation, migration and immune escape. In conclusion, clinical and biological heterogeneity is seen in DLBCL with positive BM but concordant BM involvement represents a distinct subset with unfavorable gene signatures, high-risk clinicopathologic features and poor prognosis.

Anticancer effect of quinacrine on diffuse large B‑cell lymphoma via inhibition of MSI2‑NUMB signaling pathway

Diffuse large B‑cell lymphoma (DLBCL) is the most common subtype of non‑Hodgkin's lymphoma. Despite improvements in the clinical outcomes of DLBCL, ~30% of patients will develop relapse/refractory disease. Therefore, novel therapeutic drugs have been investigated to improve disease outcomes. Previous studies have revealed the anticancer effects of quinacrine (QC) on tumor cells in vitro, although its role in human DLBCL is yet to be identified. The present study sought to examine the cytotoxic effect of QC on DLBCL cells. QC induced G0/G1 cell cycle arrest and apoptosis in the DLBCL cell lines SU‑DHL‑8 and OCI‑LY01, in a dose‑dependent manner, in addition to the downregulation of cyclin‑dependent kinase 4/6 and the upregulation of cleaved poly‑ADP ribose polymerase 1. Upon exposure to QC, RNA‑binding protein Musashi homolog 2 inactivation and activation of protein numb homolog were observed. In addition, QC was able to inhibit the expression of Myc proto‑oncogene protein. The results of the present study indicated that QC may be a potential anti‑DLBCL drug.

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.

Outcomes after Allogeneic Stem Cell Transplantation in Patients with Double-Hit and Double-Expressor Lymphoma

Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are associated with resistance to frontline and salvage immunochemotherapy, as well as autologous stem cell transplantation (SCT). We hypothesized that allogeneic SCT (alloSCT) could overcome the chemoresistance associated with DEL/DHL. We retrospectively studied the impact of DEL/DHL status in a multicenter cohort of patients who underwent alloSCT for relapsed/refractory (rel/ref) aggressive B cell non-Hodgkin lymphoma (B-NHL). Seventy-eight patients transplanted at 3 centers in whom tumor tissue was available for immunohistochemistry and fluorescence in situ hybridization were enrolled; 47% had DEL and 13% had DHL. There were no significant differences in 4-year progression-free (PFS) or overall survival (OS) between patients with DEL compared with patients without DEL (PFS 30% versus 39%, P = .24; OS 31% versus 49%, P = .17) or between patients with DHL compared with patients without DHL (PFS 40% versus 34%, P = .62; OS 50% versus 38%, P = .46). The lack of association between DEL or DHL and outcome was confirmed in multivariable models, although inadequate sample size may have limited our ability to detect significant differences. In our cohort alloSCT produced durable remissions in patients with rel/ref aggressive B-NHL irrespective of DEL and DHL status, justifying its consideration in the treatment of patients with rel/ref DEL/DHL.

LMO2-negative Expression Predicts the Presence of MYC Translocations in Aggressive B-Cell Lymphomas

MYC translocation is a defining feature of Burkitt lymphoma (BL), and the new category of high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 translocations, and occurs in 6% to 15% of diffuse large B-cell lymphomas (DLBCLs). The low incidence of MYC translocations in DLBCL makes the genetic study of all these lymphomas cumbersome. Strategies based on an initial immunophenotypic screening to select cases with a high probability of carrying the translocation may be useful. LMO2 is a germinal center marker expressed in most lymphomas originated in these cells. Mining gene expression profiling studies, we observed LMO2 downregulation in BL and large B-cell lymphoma (LBCL) with MYC translocations, and postulated that LMO2 protein expression could assist to identify such cases. We analyzed LMO2 protein expression in 46 BLs and 284 LBCL. LMO2 was expressed in 1/46 (2%) BL cases, 146/268 (54.5%) DLBCL cases, and 2/16 (12.5%) high-grade B-cell lymphoma cases with MYC and BCL2 and/or BCL6 translocations. All BLs carried MYC translocation (P<0.001), whereas LMO2 was only positive in 6/42 (14%) LBCL with MYC translocation (P<0.001). The relationship between LMO2 negativity and MYC translocation was further analyzed in different subsets of tumors according to CD10 expression and cell of origin. Lack of LMO2 expression was associated with the detection of MYC translocations with high sensitivity (87%), specificity (87%), positive predictive value and negative predictive value (74% and 94%, respectively), and accuracy (87%) in CD10 LBCL. Comparing LMO2 and MYC protein expression, all statistic measures of performance of LMO2 surpassed MYC in CD10 LBCL. These findings suggest that LMO2 loss may be a good predictor for the presence of MYC translocation in CD10 LBCL.

CUDC-907 in relapsed/refractory diffuse large B-cell lymphoma, including patients with MYC-alterations: results from an expanded phase I trial

CUDC-907 is a first-in-class, oral small molecule inhibitor of both HDAC (class I and II) and PI3K (class Iα, β, and δ) enzymes, with demonstrated anti-tumor activity in multiple pre-clinical models, including MYC-driven ones. In this report, we present the safety and preliminary activity results of CUDC-907, with and without rituximab, in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL), with a particular focus on those with MYC-altered disease. Thirty-seven DLBCL patients were enrolled, 14 with confirmed MYC-altered disease. Twenty-five patients received monotherapy treatment, and 12 received the combination of CUDC-907 with rituximab. CUDC-907 monotherapy and combination demonstrated similar safety profiles consisting primarily of Grade 1/2 hematologic and gastrointestinal events. The most frequently reported Grade ≥3 treatment-related events were thrombocytopenia, neutropenia, diarrhea, fatigue, and anemia. Eleven responses (5 complete responses and 6 partial responses) were reported, for a response rate of 37% (11 out of 30) in evaluable patients [30% (11 out of 37) including all patients]. The objective response rate in evaluable MYC-altered DLBCL patients was 64% (7 out of 11; 4 complete responses and 3 partial responses), while it was 29% (2 out of 7) in MYC unaltered, and 17% (2 out of 12) in those with unknown MYC status. Median duration of response was 11.2 months overall; 13.6 months in MYC-altered patients, 6.0 months in MYC unaltered, and 7.8 months in those with MYC status unknown. The tolerable safety profile and encouraging evidence of durable anti-tumor activity, particularly in MYC-altered patients, support the continued development of CUDC-907 in these populations of high unmet need. (clinicaltrials.gov identifier: 01742988).