Immunohistochemical detection of MYC protein correlates with MYC gene status in aggressive B cell lymphomas

C-Myc protein expression indicates unfavorable clinical outcome in surgically resected small cell lung cancer

BACKGROUND

By being highly involved in the tumor evolution and disease progression of small cell lung cancer (SCLC), Myc family members (C-Myc, L-Myc, and N-Myc) might represent promising targetable molecules. Our aim was to investigate the expression pattern and prognostic relevance of these oncogenic proteins in an international cohort of surgically resected SCLC tumors.

METHODS

Clinicopathological data and surgically resected tissue specimens from 104 SCLC patients were collected from two collaborating European institutes. Tissue sections were stained by immunohistochemistry (IHC) for all three Myc family members and the recently introduced SCLC molecular subtype-markers (ASCL1, NEUROD1, POU2F3, and YAP1).

RESULTS

IHC analysis showed C-Myc, L-Myc, and N-Myc positivity in 48%, 63%, and 9% of the specimens, respectively. N-Myc positivity significantly correlated with the POU2F3-defined molecular subtype (r = 0.6913, p = 0.0056). SCLC patients with C-Myc positive tumors exhibited significantly worse overall survival (OS) (20 vs. 44 months compared to those with C-Myc negative tumors, p = 0.0176). Ultimately, in a multivariate risk model adjusted for clinicopathological and treatment confounders, positive C-Myc expression was confirmed as an independent prognosticator of impaired OS (HR 1.811, CI 95% 1.054-3.113, p = 0.032).

CONCLUSIONS

Our study provides insights into the clinical aspects of Myc family members in surgically resected SCLC tumors. Notably, besides showing that positivity of Myc family members varies across the patients, we also reveal that C-Myc protein expression independently correlates with worse survival outcomes. Further studies are warranted to investigate the role of Myc family members as potential prognostic and predictive markers in this hard-to-treat disease.

Genetic and phenotypic characterisation of HIV-associated aggressive B-cell non-Hodgkin lymphomas, which do not occur specifically in this population: diagnostic and prognostic implications

The frequency of aggressive subtypes of B-cell non-Hodgkin lymphoma (B-NHL), such as high-grade B-cell lymphomas (HGBL) with MYC and BCL2 and/or BCL6 rearrangement (HGBL-DH/TH) or Burkitt-like lymphoma (BL) with 11q aberration, is not well known in the HIV setting. We aimed to characterise HIV-associated aggressive B-NHL according to the 2017 WHO criteria, and to identify genotypic and phenotypic features with prognostic impact. Seventy-five HIV-associated aggressive B-NHL were studied by immunohistochemistry (CD10, BCL2, BCL6, MUM1, MYC, and CD30), EBV-encoded RNAs (EBERs), and fluorescence in situ hybridisation (FISH) to evaluate the status of the MYC, BCL2, and BCL6 genes and chromosome 11q. The 2017 WHO classification criteria and the Hans algorithm, for the cell-of-origin classification of diffuse large B-cell lymphomas (DLBCL), were applied. In DLBCL cases, the frequencies of MYC and BCL6 rearrangements (14.9 and 27.7%, respectively) were similar to those described in HIV-negative patients, but BCL2 rearrangements were infrequent (4.3%). MYC expression was identified in 23.4% of DLBCL cases, and coexpression of MYC and BCL2 in 13.0%, which was associated with a worse prognosis. As for BL cases, the expression of MUM1 (30.4%) conferred a worse prognosis. Finally, the prevalence of HGBL-DH/TH and BL-like with 11q aberration are reported in the HIV setting. The phenotypic and genotypic characteristics of HIV-associated aggressive B-NHL are similar to those of the general population, except for the low frequency of BCL2 rearrangements in DLBCL. MYC and BCL2 coexpression in DLBCL, and MUM-1 expression in BL, have a negative prognostic impact on HIV-infected individuals.

Clinicopathological and Immunohistochemical Profile of Mantle Cell Lymphoma: An Institutional Experience

Introduction

Mantle cell lymphoma (MCL) is a biologically aggressive B-cell non-Hodgkin lymphoma (NHL) with distinctive morphologic, immunophenotypic, and molecular characteristics. Differentiation from other chronic lymphoproliferative disorders is essential for prognostication.

Aim

This paper aims to study the clinicopathological features of MCL with emphasis on immunohistochemical features and disease correlation.

Method

To do so, clinicopathological characteristics from 21 cases of MCL (14 males, seven females, M:F=2:1) diagnosed in the last five years i.e. 2015 to 2020, were retrospectively reviewed and correlated with immunohistochemistry (IHC) data. Particularly those pertaining to cyclin D1, SRY-box transcription factor 11 (SOX11), cluster of differentiation (CD) 5, CD23, MIB E3 ubiquitin protein ligase 1 (MIB1), tumor protein 53 (TP53), c-myelocytomatosis oncogene product (c-MYC), multiple myeloma oncogene 1 (MUM1), mouse double minute 2 homolog (MDM2), and Epstein-Barr virus latent membrane protein 1 (EBV-LMP1) expression with its aberrations.

Observations

This study shows that MCL constituted 4.2% (21/500) of all NHLs with a mean age of 57.5 years (median 60 years, range 30 to 80 years). The disease was nodal in 19, and extranodal in the remaining two cases. 14 of 21 (67%) had generalized lymphadenopathy and 71% had bone marrow (BM) involvement. The nodal involvement was diffuse in 9/17 (53%), 8/21 (38%) had a blastoid morphology, and an in-situ MCL pattern was not seen in any of the cases selected for the study. Cyclin D1 immunoexpression correlated well with SOX11; CD5-negative in five cases; and CD23-positive in three cases. TP53 and c-MYC expression were noted in 17/19 (89.4%) and 8/17 (47%), respectively. MUM1 registered positive in six cases. None of the cases showed immunopositivity for MDM2 and EBV-LMP1.

Conclusion

In essence, this study indicates that morphological and immunophenotypic subclassification of mantle cell lymphoma with a wider panel of IHC markers is essential for understanding disease biology and better prognostication.

Safety and Efficacy of a DNA Oligonucleotide Therapy in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

BACKGROUND

PNT2258 is a liposomal formulation that encapsulates multiple copies of PNT100, a native, chemically unmodified, 24-base DNA oligonucleotide designed to target the regulatory region upstream of the B-cell lymphoma 2 (BCL2) gene.

METHODS

This phase II, multicenter, single-arm, open-label, 2-stage design study investigated the single-agent activity of PNT2258 in patients with relapsed/refractory DLBCL. Initially, patients had to have a performance status (PS) of ≤2 and prior exposure to CD20-targeted therapy, an alkylating agent, and a steroid with no upper limit. Criteria were modified to PS of 0 or 1 and at least 1 to ≤3 prior therapies (identified as the target population) after observing an initially high frequency of rapid disease progression in patients with extensive prior therapies or poor PS.

RESULTS

The study was stopped early following an interim analysis, despite surpassing the protocol predetermined futility boundary, because the ORR was below the expectations of response in an evolving DLBCL treatment landscape. The final analysis included all 45 enrolled patients and demonstrated an ORR of 11%. In the response evaluable subset (n = 26), defined as patients in the target population with exposure to ≥8 doses of PNT2258 within the first 35 days and evaluable baseline/post-baseline scans, the ORR was 19%. The most common adverse events were fatigue (44%), nausea (42%), diarrhea (40%), pyrexia (36%), anemia (32%), and vomiting (27%).

CONCLUSIONS

PNT2258 was well-tolerated in a chemotherapy refractory DLBCL population. Despite demonstration of single-agent activity, ORR was lower than acceptable for further new therapy development.

Gastrointestinal Tract Lymphomas: A Review of the Most Commonly Encountered Lymphomas

CONTEXT.—

The gastrointestinal (GI) tract is the most common site of extranodal non-Hodgkin lymphoma, accounting for 20% to 40% of all extranodal lymphomas. The majority of these are systemic processes secondarily involving the GI tract. Primary GI lymphomas are less common, accounting for approximately 10% to 15% of all non-Hodgkin lymphoma. Most non-Hodgkin lymphoma involving the GI tract are of B-cell lineage, of which diffuse large B-cell lymphoma is the most common subtype, irrespective of location.

OBJECTIVE.—

To review the lymphoproliferative neoplasms of B-cell and T-cell lineage involving the luminal GI tract according to the most prevalent subtypes at each anatomic site.

DATA SOURCE.—

Systematic search of the PubMed database for updated literature on GI lymphomas epidemiology, subtypes, clinical, endoscopic, and genetic findings. Histologic images are derived from our collection of clinical cases.

CONCLUSIONS.—

The GI tract is the most common site of extranodal lymphoproliferative neoplasms. Recognition of the most frequently encountered GI lymphomas is imperative for patient management and treatment.

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.

Reliable cell and tissue morphology-based diagnosis of endemic Burkitt lymphoma in resource-constrained settings in Ghana

BACKGROUND

Endemic Burkitt lymphoma (eBL) is an aggressive B-cell lymphoma, which is a common childhood cancer in areas with intense transmission of Plasmodium falciparum parasites. Early and accurate diagnosis is a prerequisite for successful therapy, but it optimally involves advanced laboratory investigations. These are technologically demanding, expensive, and often difficult to implement in settings where eBL is prevalent. Diagnosis is thus generally based on clinical assessment and morphological examination of tumour biopsies or fine-needle aspirates (FNAs).

METHODS

The purpose of the present study was to assess the accuracy of eBL diagnosis at two tertiary hospitals in Ghana. To that end, we studied FNAs from 29 eBL patients and 21 non-eBL lymphoma patients originally diagnosed in 2018. In addition, we examined 111 archival formalin-fixed and paraffin-embedded (FFPE) biopsies from Ghanaian patients originally diagnosed as eBL (N = 55) or non-eBL (N = 56) between 2010 and 2017. Availability-based subsets of samples were subjected to haematoxylin-eosin or Giemsa staining, C-MYC immunohistochemistry, and fluorescence in situ hybridisation (FISH) analysis of c-myc rearrangements.

RESULTS

We found a good correlation between original diagnosis and subsequent retrospective assessment, particularly for FNA samples. However, evidence of intact c-myc genes and normal C-MYC expression in samples from some patients originally diagnosed as eBL indicates that morphological assessment alone can lead to eBL over-diagnosis in our study area. In addition, several FFPE samples could not be assessed retrospectively, due to poor sample quality. Therefore, the simpler FNA method of obtaining tumour material is preferable, particularly when careful processing of biopsy specimens cannot be guaranteed.

CONCLUSION

We conclude that the accuracy of eBL diagnostic tools available in Ghana is generally adequate, but could be improved by implementation of additional pathology laboratory investigations. Improved attention to adequate preservation of archival samples is recommended.

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.

Advances in Diagnosis and Management of Diffuse Large B-cell Lymphoma

The management of diffuse large B-cell lymphoma (DLBCL) has been gradually evolving since the discovery of its 2 major forms, the germinal center B-like (GCB) and activated B-cell (ABC) types. Although the reference standard for the identification of these cell types is considered gene expression profiling (GEP), currently the only method commercially available is immunohistochemistry (IHC). The application of various IHC-based algorithms and their correlation with GEP and clinical outcome are discussed. Because of the adverse prognostic implications of the non-GCB type and its potential effects on treatment selection, the recently revised World Health Organization classification has included these biologic cell types. The management of double hit lymphomas, which almost exclusively fall under the GCB category, is discussed, together with the double expresser phenotype, which is usually grouped under the non-GCB type. The role of lenalidomide and ibrutinib in the management of the non-GCB type is examined. We also discuss the front-line management of primary mediastinal large cell lymphoma using the EPOCH (etoposide, prednisolone, Oncovin [vincristine], cyclophosphamide, hydroxydaunorubicin [doxorubicin]) regimen and examine new salvage data on immune checkpoint inhibitors for this clinical subtype. The prognosis, clinical features, and management of de novo CD5+ DLBCL are discussed, and newer and promising developments in the management of primary central nervous system lymphomas are presented in detail. The most popular salvage regimens and the application of high-dose chemotherapy with stem cell transplantation are assessed in detail. Finally, data on new treatment tactics such as CART (chimeric antigen receptor T-cell) cells and promising new drugs, including blinatumomab and venetoclax, are presented.

MYC Immunohistochemistry Predicts MYC Rearrangements by FISH

MYC is the proto-oncogene classically associated with Burkitt lymphoma (BL) located at chromosomal locus 8q24. Rearrangements of MYC are seen in nearly 100% of BL but have been reported in 3–16% of diffuse large B-cell lymphomas (DLBCLs). Rearrangements of MYC are tested for by flourescence in situ hybridization (FISH). In this study, we compared immunohistochemistry (IHC) using a monoclonal antibody directed against the human Myc protein to the current method, FISH. 31 cases were identified that had been tested for MYC rearrangements by FISH over 27 months with heterogeneity in the diagnoses: 5 BL; 10 DLBCL; 3 B-cell lymphoma unclassifiable between DLBCL and BL; 5 B-cell lymphoma not otherwise specified; 1 EBV-related B-cell lymphoma; 1 composite CLL/SLL-large cell lymphoma; and 6 designated as high-grade or aggressive B-cell lymphoma. Analysis by FISH was performed as part of the clinical workup, where a MYC rearrangement is defined as a split fusion signal in at least 5.7% of cells. Myc-IHC was interpreted as a qualitative positive (overexpressed) or negative (not overexpressed) result. 12 cases (39%) were positive for MYC rearrangements by FISH. Overall, 13 cases (42%) showed Myc overexpression by IHC, 11 of which harbored a MYC rearrangement by FISH. There were two false positives and one false negative. Thus, Myc-IHC predicted a MYC rearrangement by FISH with 92% sensitivity and 89% specificity. We can thus conclude that Myc-IHC should be a potentially useful screening tool for identifying lymphomas that may harbor a MYC rearrangement.

Immunohistochemical Profile of MYC Protein in Pediatric Small Round Blue Cell Tumors

Deregulation of MYC oncoprotein in cancers can result from multiple oncogenic mechanisms. Although MYC translocations define Burkitt lymphoma and MYC protein expression is a poor prognostic factor in undifferentiated neuroblastomas, the distribution of MYC protein (c-MYC) across other pediatric small round blue cell tumors (SRBCT) has not been well characterized. We undertook this study to assess MYC protein expression in a large cohort of pediatric lymphomas, sarcomas, and other SRBCT. Tissue microarrays containing 302 SRBCT were successfully evaluated by immunohistochemistry using anti-MYC clone Y69, with nuclear positivity scored as 0%, 1%-25%, 26%-50%, 51%-75%, or 76%-100%. MYC protein staining of >50% of lesional cells was identified in 60% of Burkitt lymphomas, 50% of B lymphoblastic lymphomas, 33% of T lymphoblastic lymphomas, 31% of rhabdomyosarcomas, 33% of Ewing sarcomas, and 25% of soft tissue sarcomas, not otherwise specified. Only 14% of neuroblastomas showed >50% staining, and of these, if known, MYCN was not amplified. No cases of Wilms tumor, synovial sarcoma, or desmoplastic small round cell tumor had >50% staining. Recurrences and metastases often had the same percentage of MYC staining (15/30). In conclusion, MYC protein exhibited variable expression across and within pediatric SRBCT subtypes. Overall, these findings provide a baseline for MYC expression in pediatric SRBCT and suggest that there may be multiple mechanisms of MYC upregulation in these different neoplasms.

The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects

c-MYC is one of the most essential transcriptional factors, regulating a diverse array of cellular functions, including proliferation, growth, and apoptosis. Dysregulation of c-MYC is essential in the pathogenesis of a number of B-cell lymphomas, but is rarely reported in T-cell lymphomas. c-MYC dysregulation induces lymphomagenesis by loss of the tight control of c-MYC expression, leading to overexpression of intact c-MYC protein, in contrast to the somatic mutations or fusion proteins seen in many other oncogenes. Dysregulation of c-MYC in B-cell lymphomas occurs either as a primary event in Burkitt lymphoma, or secondarily in aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, mantle cell lymphoma, or double-hit lymphoma. Secondary c-MYC changes include gene translocation and gene amplification, occurring against a background of complex karyotype, and most often confer aggressive clinical behavior, as evidenced in the double-hit lymphomas. In low-grade B-cell lymphomas, acquisition of c-MYC rearrangement usually results in transformation into highly aggressive lymphomas, with some exceptions. In this review, we discuss the role that c-MYC plays in the pathogenesis of B-cell lymphomas, the molecular alterations that lead to c-MYC dysregulation, and their effect on prognosis and diagnosis in specific types of B-cell lymphoma.

Crebbp loss cooperates with Bcl2 overexpression to promote lymphoma in mice

CREBBP is targeted by inactivating mutations in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). Here, we provide evidence from transgenic mouse models that Crebbp deletion results in deficits in B-cell development and can cooperate with Bcl2 overexpression to promote B-cell lymphoma. Through transcriptional and epigenetic profiling of these B cells, we found that Crebbp inactivation was associated with broad transcriptional alterations, but no changes in the patterns of histone acetylation at the proximal regulatory regions of these genes. However, B cells with Crebbp inactivation showed high expression of Myc and patterns of altered histone acetylation that were localized to intragenic regions, enriched for Myc DNA binding motifs, and showed Myc binding. Through the analysis of CREBBP mutations from a large cohort of primary human FL and DLBCL, we show a significant difference in the spectrum of CREBBP mutations in these 2 diseases, with higher frequencies of nonsense/frameshift mutations in DLBCL compared with FL. Together, our data therefore provide important links between Crebbp inactivation and Bcl2 dependence and show a role for Crebbp inactivation in the induction of Myc expression. We suggest this may parallel the role of CREBBP frameshift/nonsense mutations in DLBCL that result in loss of the protein, but may contrast the role of missense mutations in the lysine acetyltransferase domain that are more frequently observed in FL and yield an inactive protein.

Definition of MYC genetic heteroclonality in diffuse large B-cell lymphoma with 8q24 rearrangement and its impact on protein expression

MYC rearrangement can be detected in a subgroup of diffuse large B-cell lymphoma characterized by unfavorable prognosis. In contrast to Burkitt lymphoma, the correlation between MYC rearrangement and MYC protein expression in diffuse large B-cell lymphoma is less clear, as approximately one-third of rearranged cases show negative or low expression by immunohistochemistry. To better understand whether specific characteristics of the MYC rearrangement may influence its protein expression, we investigated 43 de novo diffuse large B-cell lymphoma positive for 8q24 rearrangement by FISH, using 14 Burkitt lymphoma for comparison. Different cell populations (clones), breakpoints (classical vs non-classical FISH patterns), partner genes (IGH vs non-IGH) and immunostaining were detected and analyzed using computerized image systems. In a subgroup of diffuse large B-cell lymphoma, we observed different clones within the same tumor distinguishing the founder clone with MYC rearrangement alone from other subclones, carrying MYC rearrangement coupled with loss/extra copies of derivatives/normal alleles. This picture, which we defined MYC genetic heteroclonality, was found in 42% of cases and correlated to negative MYC expression (P=0.026). Non-classical FISH breakpoints were detected in 16% of diffuse large B-cell lymphoma without affecting expression (P=0.040). Non-IGH gene was the preferential partner of rearrangement in those diffuse large B-cell lymphoma showing MYC heteroclonality (P=0.016) and/or non-classical FISH breakpoints (P=0.058). MYC heteroclonality was not observed in Burkitt lymphoma and all cases had positive MYC expression. Non-classical FISH MYC breakpoint and non-IGH partner were found in 29 and 20% of Burkitt lymphoma, respectively. In conclusion, MYC genetic heteroclonality is a frequent event in diffuse large B-cell lymphoma and may have a relevant role in modulating MYC expression.

Acute myeloid leukaemia: expression of MYC protein and its association with cytogenetic risk profile and overall survival

Acute myeloid leukaemia (AML) is a clinically aggressive disease with marked genetic heterogeneity. Cytogenetic abnormalities provide the basis for risk stratification into clinically favourable, intermediate, and unfavourable groups. There are additional genetic mutations, which further influence the prognosis of patients with AML. Most of these result in molecular aberrations whose downstream target is MYC. It is therefore logical to study the relationship between MYC protein expression and cytogenetic risk groups. We studied MYC expression by immunohistochemistry in a large cohort (n = 199) of AML patients and correlated these results with cytogenetic risk profile and overall survival (OS). We illustrated differential expression of MYC protein across various cytogenetic risk groups (p = 0.03). Highest expression of MYC was noted in AML patients with favourable cytogenetic risk group. In univariate analysis, MYC expression showed significant negative influence of OS in favourable and intermediate cytogenetic risk group (p = 0.001). Interestingly, MYC expression had a protective effect in the unfavourable cytogenetic risk group. In multivariate analysis, while age and cytogenetic risk group were significant factors influencing survival, MYC expression by immunohistochemistry methods also showed some marginal impact (p = 0.069). In conclusion, we have identified differential expression of MYC protein in relation to cytogenetic risk groups in AML patients and documented its possible impact on OS in favourable and intermediate cytogenetic risk groups. These preliminary observations mandate additional studies to further investigate the routine clinical use of MYC protein expression in AML risk stratification. Copyright © 2016 John Wiley & Sons, Ltd.

Clinical features, tumor biology, and prognosis associated with MYC rearrangement and Myc overexpression in diffuse large B-cell lymphoma patients treated with rituximab-CHOP

MYC dysregulation, including MYC gene rearrangement and Myc protein overexpression, is of increasing clinical importance in diffuse large B-cell lymphoma (DLBCL). However, the roles of MYC and the relative importance of rearrangement vs overexpression remain to be refined. Gaining knowledge about the tumor biology associated with MYC dysregulation is important to understand the roles of MYC and MYC-associated biology in lymphomagenesis. In this study, we determined MYC rearrangement status (n=344) and Myc expression (n=535) in a well-characterized DLBCL cohort, individually assessed the clinical and pathobiological features of patients with MYC rearrangement and Myc protein overexpression, and analyzed the prognosis and gene expression profiling signatures associated with these MYC abnormalities in germinal center B-cell-like and activated B-cell-like DLBCL. Our results showed that the prognostic importance of MYC rearrangement vs Myc overexpression is significantly different in germinal center B-cell-like vs activated B-cell-like DLBCL. In germinal center B-cell-like DLBCL, MYC-rearranged germinal center B-cell-like DLBCL patients with Myc overexpression significantly contributed to the clinical, biological, and prognostic characteristics of the overall Myc-overexpressing germinal center B-cell-like DLBCL group. In contrast, in activated B-cell-like DLBCL, the occurrence, clinical and biological features, and prognosis of Myc overexpression were independent of MYC rearrangement. High Myc levels and Myc-independent mechanisms, either tumor cell intrinsic or related to tumor microenvironment, conferred significantly worse survival to MYC-rearranged germinal center B-cell-like DLBCL patients, even among Myc(high)Bcl-2(high) DLBCL patients. This study provides new insight into the tumor biology and prognostic effects associated with MYC dysregulation and suggest that detection of both MYC translocations and evaluation of Myc and Bcl-2 expression is necessary to predict the prognosis of DLBCL patients.

Combination of BCL-2 and MYC protein expression improves high-risk stratification in diffuse large B-cell lymphoma

Purpose

To evaluate whether the addition of two biological markers (MYC and BCL-2 protein overexpression) improves the stratification of high-risk patients with diffuse large B-cell lymphoma (DLBCL).

Method

Seven risk factors were identified at diagnosis, and a maximum of 7 points were assigned to each patient. The patients were classified according to four risk groups: low (0–1), low-intermediate (2–3), high-intermediate (4), and high (5–7). Only high-risk patients with DLBCL were included in this analysis. We retrospectively examined 20 cases from 2008 to 2013 at the Nanjing Drum Tower Hospital.

Results

The median expression of MYC protein was 60%, and 17 of 20 (65%) evaluable cases overexpressed MYC. The median expression of BCL-2 protein was also 60%. Eighteen of 20 (90%) evaluable cases showed BCL-2 overexpression. Additionally, 12 out of 20 cases (60%) demonstrated coexpression of MYC and BCL-2 proteins. The percentages of overall survival and progression-free survival at the median follow-up time (36 months) were 33.3%±16.1% and 16.9%±13.5%, respectively. By comparison, nine, four, and 20 patients were classified as high risk based on the International Prognostic Index (IPI), National Comprehensive Cancer Network(NCCN)-IPI, and revised IPI criteria, respectively. According to the IPI and NCCN-IPI stratification, the risk groups demonstrated closely overlapping survival curves. In addition, four out of 20 cases were identified as low-intermediate risk according to the NCCN-IPI criteria.

Conclusion

The addition of MYC and BCL-2 protein expression to the IPI could identify a subset of DLBCL patients with high-risk clinicopathological characteristics and poor clinical outcome.

Genetic lesions in diffuse large B-cell lymphomas

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in adults, accounting for 35%-40% of all cases. The combination of the anti-CD20 monoclonal antibody rituximab with anthracycline-based combination chemotherapy (R-CHOP, rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone) lead to complete remission in most and can cure more than half of patients with DLBCL. The diversity in clinical presentation, as well as the pathologic and biologic heterogeneity, suggests that DLBCL comprises several disease entities that might ultimately benefit from different therapeutic approaches. In this review, we summarize the current literature focusing on the genetic lesions identified in DLBCL.

MYC protein expression is associated with poor prognosis in primary diffuse large B-cell lymphoma of the central nervous system

MYC and BCL2 gene translocations and protein expression have recently demonstrated to be of prognostic significance in systemic diffuse large B-cell lymphoma (DLBCL). However, their role in primary central nervous system DLBCL (CNS-DLBCL) prognosis has been scarcely analyzed. We studied the immunophenotype, the status of the MYC, BCL2, and BCL6 genes and the clinical features of a series of 42 CNS-DLBCL and evaluated their prognostic significance. We found high MYC protein expression in 43% of cases, and this was associated with lower overall survival (OS). Cases with concurrent expression of MYC and BCL2 showed a lower OS, although the difference did not reach statistical significance. Translocations involving the MYC or BCL2 genes were not detected. The BCL6 gene was frequently translocated, but was unrelated to survival. We conclude that MYC protein expression detected by immunohistochemistry identifies a CNS-DLBCL subset with worse prognosis and may contribute to a more accurate risk stratification of CNS-DLBCL patients.

Clinicopathologic evaluation of MYC expression in primary mediastinal (thymic) large B-cell lymphoma

OBJECTIVES

Based on previous molecular studies, a small fraction of primary mediastinal (thymic) large B-cell lymphoma (PMBL) demonstrates MYC alterations. However, no studies have evaluated MYC protein expression by immunohistochemistry (IHC) with follow-up fluorescence in situ hybridization (FISH) analysis. We aim to evaluate the clinicopathologic importance of MYC IHC expression in PMBL.

METHODS

Three pathologists independently evaluated MYC IHC expression in 32 cases of PMBL for percent tumor positivity and nuclear intensity. FISH analysis for MYC rearrangement was performed on cases with high MYC IHC expression. Clinical data including treatment, follow-up, and outcome were also reviewed in a subset of cases.

RESULTS

Variable MYC protein expression by IHC was detected in 30 (94%) of 32 cases of PMBL. One-third of the positive cases (10/30) showed high MYC IHC expression of at least 30% nuclear positivity. FISH analyses for MYC rearrangement on these 10 cases were negative. Review of clinical data on a subset of cases with high and low MYC IHC expression showed no differences in clinical outcome.

CONCLUSIONS

MYC protein expression by IHC is present in most PMBLs. Increased MYC protein expression can be seen in one-third of the cases; however, it does not correlate with genetic abnormalities by FISH. There is also no significant impact of MYC protein expression on clinical outcomes.

Myc protein expression correlates with MYC amplification in small-cell lung carcinoma

AIMS

Myc family members are important contributors to oncogenesis in a variety of tumours. Identification of therapeutic targets is needed in small-cell lung carcinoma (SCLC), an aggressive disease with limited treatment options. Sequencing studies have identified MYC amplification in 2-7% of SCLCs. This study aims to determine the rate of MYC gene amplification and its correlation with Myc protein overexpression in SCLC.

METHODS AND RESULTS

One hundred and three cases of formalin-fixed, paraffin-embedded SCLC were examined. Myc protein expression was scored according to the extent of immunohistochemical staining. MYC copy number (CN) was evaluated with dual-colour chromogenic in-situ hybridization (CISH) for the MYC locus and a chromosome 8 (Chr8) centromeric control. Amplification was defined as a MYC/Chr8 ratio of ≥2. Thirty-eight per cent of SCLCs had some degree of Myc protein expression, and 9% of cases were MYC-amplified. MYC CN was significantly correlated with the extent of Myc protein expression (Spearman's ρ = 0.57, P < 0.01). There was no significant association between Myc expression or CN and clinicopathological features.

CONCLUSIONS

MYC amplification by CISH was identified in 9% of SCLCs, and correlated with protein expression. As novel Myc-targeted therapies are developed, CISH and IHC should be considered as biomarkers of Myc pathway dysregulation in SCLC.

Practical Applications in Immunohistochemistry: Evaluation of Diffuse Large B-Cell Lymphoma and Related Large B-Cell Lymphomas

Context

Diffuse large B-cell lymphoma is the most commonly diagnosed subtype of lymphoma worldwide. The current World Health Organization (WHO) classification includes several subtypes, based on a combination of clinical, immunohistochemical, and genetic differences. Immunohistochemical staining is essential in evaluating diffuse large B-cell lymphoma and many related large B-cell lymphomas and aggressive B-cell lymphomas.

Objective

To address different immunohistochemical features used for identification, subclassification, prognosis and in some cases, therapy, of diffuse large B-cell lymphoma and related lymphomas.

Data Sources

The information outlined in this review article is based on our experiences with routine cases, on the current WHO classification of hematopoietic and lymphoid tumors, and on a review of English-language articles published throughout 2014.

Conclusions

Features and diagnostic criteria of diffuse large B-cell lymphoma, aggressive variants of B-cell lymphomas, including Burkitt lymphoma and “double-hit” lymphomas, are discussed. Identification of cell of origin (germinal center type versus activated B-cell type) is discussed at length. Finally, practical approaches for diagnosis are discussed.

New Immunohistochemistry for B-Cell Lymphoma and Hodgkin Lymphoma

Context

B-cell non-Hodgkin lymphoma is a heterogeneous group of lymphoproliferative malignancies with different clinical behaviors and treatments. It is important to differentiate individual B-cell lymphoma to apply the best treatment and management. Morphology and immunohistochemistry are the primary tools used for diagnosing lymphoma. There is a characteristic pattern of expression with immunohistochemical antibodies in most well-defined B-cell lymphomas. Some cases of B-cell lymphoma, however, show unusual morphologic and immunophenotypic features. The new and sometimes more specific antibodies have been developed recently, which may further define those lymphomas. Only with use of the antibodies over time does their true nature and specificity become evident.

Objectives

To present new antibodies for B-cell lymphoma that enhance the probability for diagnosis or can act as alternate markers in unusual cases, in which a B-cell lymphoma does not present with characteristic immunohistochemical staining, and to present prognostic markers that allow for better management of patients with specific B-cell lymphomas.

Data Sources

Data were obtained from literature review and figures from slides in personal practice.

Conclusions

The immunohistochemical antibodies presented in this article increase our ability to understand, diagnosis, and manage patients with B-cell lymphoma.

Rearrangements of MYC gene facilitate risk stratification in diffuse large B-cell lymphoma patients treated with rituximab-CHOP

In order to address the debatable prognostic role of MYC rearrangements in diffuse large B-cell lymphoma patients treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone, we evaluated MYC rearrangements by fluorescence in situ hybridization in 563 cases using break-apart probes and IGH/MYC dual-fusion probes. Concurrent BCL2 and BCL6 aberrations were also assessed. Data were correlated with clinicopathological variables and prognostic parameters. MYC rearrangements were observed in 39/432 evaluable cases (9%), including 4 rearrangements detectable only with the dual-fusion probes, 15 detectable only with the break-apart probes and 20 detectable with both dual-fusion probes and break-apart probes. MYC rearrangements correlated with germinal center B-cell origin (P=0.02), MYC protein expression (P=0.032), and larger tumor mass size (P=0.0003). Patients with MYC rearrangements were more likely to be treatment resistant (P<0.0001). All types of MYC rearrangements were associated with poorer disease-specific survival, that is, 20/39 dead, median disease-specific survival 42 months, compared with 98/393 dead among the non-rearranged cases, median disease-specific survival not reached (P=0.0002). Cases with MYC rearrangements that overexpressed MYC protein were at risk with respect to disease-specific survival independent of the International Prognostic Index (P=0.046 and P<0.001, respectively). Presence of concurrent BCL2 aberrations but not of BCL6 aberrations was prognostically additive. Radiotherapy seemed to diminish the prognostic effects of MYC rearrangements in diffuse large B-cell lymphoma patients since only 2/10 irradiated patients with MYC rearrangements died of/with disease, compared with 16/28 non-irradiated patients with MYC rearrangements. We conclude that MYC rearrangements add prognostic information for individual risk estimation and such cases might represent a distinct, biologically determined disease subgroup.

Clinical significance of MYC expression and/or "high-grade" morphology in non-Burkitt, diffuse aggressive B-cell lymphomas: a SWOG S9704 correlative study

The clinicopathologic findings in Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) may show significant overlap, and MYC abnormalities, found in all BLs, also occur in a subset of DLBCL. The 2008 World Health Organization classification introduced the category of "B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL" (BCLU) in recognition of this overlap, but the clinical significance of BCLU (ie, "high-grade") morphology and the relationship between BCLU morphology and MYC abnormalities remains unclear. In this study, we identified 260 cases of non-Burkitt, diffuse aggressive B-cell lymphomas from SWOG S9704, a phase 3 randomized study of standard immunochemotherapy versus autologous stem cell transplantation. Of these, 31 cases (12%) showed BCLU morphology, and 229 (88%) showed typical DLBCL morphology. Of 198, 27 (14%) were positive for MYC by immunohistochemistry. BCLU morphology was associated with an increased incidence of MYC expression but otherwise was not associated with distinct clinicopathologic features or significantly decreased survival. MYC-positive cases were morphologically and phenotypically heterogenous and were associated with poor progression-free and overall survival in multivariate analysis. These findings confirm that BCLU does not represent a distinct clinicopathologic entity and demonstrate that BCLU morphology alone does not significantly impact survival compared with typical DLBCL. In contrast, MYC protein expression is a poor prognostic factor that may be associated with either BCLU or DLBCL morphology, and MYC immunohistochemistry is suggested for routine prognostic evaluation (Clinicaltrials.gov identifier: NCT00004031).

MYC protein expression is associated with poor prognosis in diffuse large B cell lymphoma patients treated with RCHOP chemotherapy

This study aims to investigate the prognostic significance of the MYC protein expression in diffuse large B cell lymphoma (DLBCL) patients treated with RCHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone). A total of 60 patients with DLBCL from 2008 to 2013 were included. Formalin-fixed, paraffin-embedded DLBCL samples were analyzed for MYC protein expression and divided into high or low MYC group. The MYC protein expression and the international prognostic variables were evaluated. The high MYC protein expression predicted a shorter 3-year estimated overall survival (OS) and progression-free survival (PFS) versus the low MYC protein expression (57 % vs. 96 %, P < 0.001 and 50 % vs. 96 %, P = 0.001, respectively). Multivariate analysis confirmed the prognostic significance of the MYC protein expression for both OS (HR, 11.862; 95 % CI, 1.462-96.218; P = 0.021) and PFS (HR, 6.073; 95 % CI, 1.082-34.085; P = 0.040). MYC protein expression with International Prognostic Index (IPI) score distinguished patients into three risk groups with different 3-year OS rates (χ (2) 23.079; P < 0.001) and distinct 3-year PFS rates (χ (2) 15.862; P < 0.001). This study suggests that the MYC protein expression is an important inferior prognostic factor for survival in patients with DLBCL treated with RCHOP. The combinative model with IPI score and MYC protein expression could stratify DLBCL patients into prognostically relevant subgroups more effectively than either the IPI or the MYC alone.

p53 expression is a strong marker of inferior survival in de novo diffuse large B-cell lymphoma and may have enhanced negative effect with MYC coexpression: a single institutional clinicopathologic study

OBJECTIVES

To examine interactions among clinical factors and pathologic biomarkers in predicting the outcome of patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab-based immunochemotherapy.

METHODS

In 85 patients treated at a single institution, clinicopathologic variables were analyzed, including the International Prognostic Index (IPI); germinal/nongerminal center phenotype; MYC, p53, BCL2, Ki-67, and Epstein-Barr virus (EBV) expression; and MYC translocation status.

RESULTS

In univariate analysis, overall survival (OS) was worse for patients with high IPI scores, nongerminal center phenotype, high MYC and p53 expression by immunohistochemistry, and EBV positivity. In multivariable analysis, p53 expression was the strongest prognostic factor (P < .05) independent of IPI and cell of origin. A significant positive association between p53 and MYC expression was found. Moreover, coexpression of p53/MYC had an enhanced negative effect on OS independent of BCL2 expression.

CONCLUSIONS

Immunohistochemical assessment of p53, particularly in combination with MYC, could be useful in identifying a high-risk subgroup of DLBCL.

ALK-positive large B-cell lymphomas express a terminal B-cell differentiation program and activated STAT3 but lack MYC rearrangements

ALK-positive large B-cell lymphoma is an aggressive lymphoid neoplasm characterized by a monomorphic proliferation of immunoblast-like cells expressing a plasmablastic phenotype and carrying ALK rearrangements. MYC rearrangements are frequent in plasmablastic lymphomas, advanced plasma cell myelomas and a subgroup of diffuse large B-cell lymphomas, but their presence in ALK-positive large B-cell lymphomas is unknown. MYC expression is downregulated by BLIMP1, a master modulator of plasma cell differentiation. BLIMP1 and MYC are upregulated by STAT3, a signal transducer activated by ALK. To determine the role of BLIMP1, MYC and STAT3 in the pathogenesis of ALK-positive large B-cell lymphomas, we investigated MYC rearrangement and the expression of MYC, phosphorylated STAT3, BLIMP1, PAX5 and XBP1 in 12 ALK-positive large B-cell lymphomas. All cases expressed ALK with a granular cytoplasmic pattern. Nine cases had a split signal consistent with an ALK rearrangement. Three additional cases showed a deletion of the 5' or 3' end of the ALK probe consistent with cryptic translocation. PAX5 was virtually negative in all cases tested, whereas BLIMP1 was expressed in all tumors and XBP1 in 11 of 12. Phosphorylated STAT3 was observed in all cases with a strong and diffuse nuclear pattern. MYC rearrangements were not identified in any tumor, but MYC gains and amplification were detected in six cases and one case, respectively. MYC protein was expressed in all tumors independently of MYC gene alterations. These results indicate that ALK-positive large B-cell lymphomas express a complete plasmablastic differentiation program but, contrary to plasmablastic lymphomas, do not have MYC rearrangements. STAT3 is constantly activated and may be an alternative mechanism to promote MYC expression in these tumors. The relevance of the ALK/STAT3 pathway in the pathogenesis of ALK-positive large B-cell lymphomas may offer an attractive target for new therapies.

Immunohistochemical evaluation of MYC expression in mantle cell lymphoma

AIM

To assess the validity and potential clinical utility of evaluating MYC expression by immunohistochemistry (IHC) in mantle cell lymphoma (MCL).

METHODS AND RESULTS

MYC IHC was scored on a tissue microarray containing 62 MCLs and 29 controls by two pathologists. Inter-observer correlation was high (intra-class correlation of 0.98). MYC IHC scores correlated with MYC expression (Spearman's rank correlation 0.69, P < 0.0001) and weakly with Ki67 proliferation index (Spearman's rank correlation 0.30, P = 0.03). Six blastic MCLs did not have higher mean MYC IHC scores or MYC mRNA expression than non-blastic MCLs. None of 57 cases assessed, including all of the blastic cases, showed MYC rearrangement by fluorescence in-situ hybridization. Multivariate analysis with backward selection from potential predictors including age, lactate dehydrogenase, leukocyte count, MIPI score, ECOG performance status, blastic morphology and Ki67 index showed that MYC IHC score is an independent predictor of progression-free survival (hazard ratio 2.34, 95% CI 1.42-3.88, P = 0.0009) and overall survival (hazard ratio 1.90, 95% CI 1.05-3.43, P = 0.034).

CONCLUSIONS

We show that a new monoclonal anti-MYC antibody can enable accurate and reproducible visual assessment of MYC expression that is independently predictive of clinical outcomes in MCL.

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

MYC alterations influence the survival of patients with diffuse large B-cell lymphoma. Most studies have focused on MYC translocations but there is little information regarding the impact of numerical alterations and protein expression. We analyzed the genetic alterations and protein expression of MYC, BCL2, BCL6, and MALT1 in 219 cases of diffuse large B-cell lymphoma. MYC rearrangement occurred as the sole abnormality (MYC single-hit) in 3% of cases, MYC and concurrent BCL2 and/or BCL6 rearrangements (MYC double/triple-hit) in 4%, MYC amplifications in 2% and MYC gains in 19%. MYC single-hit, MYC double/triple-hit and MYC amplifications, but not MYC gains or other gene rearrangements, were associated with unfavorable progression-free survival and overall survival. MYC protein expression, evaluated using computerized image analysis, captured the unfavorable prognosis of MYC translocations/amplifications and identified an additional subset of patients without gene alterations but with similar poor prognosis. Patients with tumors expressing both MYC/BCL2 had the worst prognosis, whereas those with double-negative tumors had the best outcome. High MYC expression was associated with shorter overall survival irrespectively of the International Prognostic Index and BCL2 expression. In conclusion, MYC protein expression identifies a subset of diffuse large B-cell lymphoma with very poor prognosis independently of gene alterations and other prognostic parameters.

High levels of bcl-2 protein expression do not correlate with genetic abnormalities but predict worse prognosis in patients with lymphoblastic lymphoma

We aimed to investigate bcl-2, bcl-6, and c-myc rearrangements in patients with lymphoblastic lymphoma (LBL), especially focus on the correlation of protein expression with genetic abnormalities. Moreover, their prognostic significance was further analyzed in LBL. Protein expression and genetic abnormalities of bcl-2, bcl-6, and c-myc were investigated in microarrayed tumors from 33 cases of T cell LBL and eight cases of B cell lineage. Immunohistochemical (IHC) staining was performed to evaluate protein expression, including bcl-2, bcl-6, c-myc, TdT, CD1α, CD34, Ki-67, PAX-5, CD2, CD3, CD4, CD8, and CD20. Genetic abnormalities of bcl-2, bcl-6, and c-myc were detected by dual color fluorescence in situ hybridization (FISH). Bcl-2 protein was positive in 51.2 % (21/41) of the patients, bcl-6 protein in 7.3 % (three out of 41), and c-myc protein in 78.0 % (32/41). Bcl-2 breakpoint was found in two cases by FISH analysis. There was no evidence of bcl-6 or c-myc rearrangement in patients with LBL. However, both gene gain and loss events occurred in bcl-2, bcl-6, and c-myc. A univariate analysis showed that stage III or IV, elevated lactate dehydrogenase (LDH), and positivity for bcl-2 protein were associated with shorter survival (p<0.05). Enhanced protein expression and detectable genetic abnormalities of bcl-2, bcl-6, and c-myc were observed in patients with LBL. No statistical correlation was found between IHC results and cytogenetic findings. Stage III or IV, elevated LDH, and positivity for bcl-2 protein were identified as adverse prognostic factors. The patients with more adverse factors would have increasingly worse prognosis.

Immunohistochemical double-hit score is a strong predictor of outcome in patients with diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone

PURPOSE

Approximately 5% of diffuse large B-cell lymphomas (DLBCLs) are double-hit lymphomas (DHLs) with translocations of both MYC and BCL2. DHLs are characterized by poor outcome. We tested whether DLBCLs with high expression of MYC protein and BCL2 protein share the clinical features and poor prognosis of DHLs.

PATIENTS AND METHODS

Paraffin-embedded lymphoma samples from 193 patients with de novo DLBCL who were uniformly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were studied using immunohistochemistry for MYC, BCL2, CD10, BCL6, and MUM1/interferon regulatory factor 4, and fluorescent in situ hybridization (FISH) for MYC and BCL2.

RESULTS

FISH analysis identified DHL in 6% of patients, who showed the expected poor overall survival (OS; P = .002). On the basis of immunohistochemical MYC and BCL2 expression, a double-hit score (DHS) was assigned to all patients with DLBCL. The DHS-2 group, defined by high expression of both MYC and BCL2 protein, comprised 29% of the patients. DHS 2 was significantly associated with lower complete response rate (P = .004), shorter OS (P < .001), and shorter progression-free survival (PFS; P < .001). The highly significant correlation with OS and PFS was maintained in multivariate models that controlled for the International Prognostic Index and the cell-of-origin subtype (OS, P < .001; PFS, P < .001). DHS was validated in an independent cohort of 116 patients who were treated with R-CHOP.

CONCLUSION

The immunohistochemical DHS defined a large subset of DLBCLs with double-hit biology and was strongly associated with poor outcome in patients treated with R-CHOP.