MYC protein is a high-risk factor in mantle cell lymphoma and identifies cases beyond morphology, proliferation and TP53/p53 - a Nordic Lymphoma Group study.

The transcription factor MYC is a well-described oncogene with an important role in lymphomagenesis, but its significance for clinical outcome in mantle cell lymphoma (MCL) remains to be determined. We performed an investigation of the expression of MYC protein in a cohort of 251 MCL patients complemented by analyses of structural aberrations and mRNA, in a sub-cohort of patients. Fourteen percent (n=35) of patients showed high MYC protein expression with >20% positive cells (MYChigh), among whom only one translocation was identified, and 86% (n=216) of patients showed low MYC protein expression. Low copy number gains of MYC were detected in ten patients, but with no correlation to MYC protein levels. However, MYC mRNA levels correlated significantly to MYC protein levels with a R2 value of 0.76. Patients with a MYChigh tumor had both an independent inferior overall survival and an inferior progression-free survival (hazard ratio [HR]=2.03, 95% confidence interval [95% CI]: 1.2-3.4 and HR=2.2, 95% CI: 1.04-4.6, respectively) when adjusted for additional high-risk features. Patients with MYChigh tumors also tended to have additional high-risk features and to be older at diagnosis. A subgroup of 13 patients had concomitant MYChigh expression and TP53/p53 alterations and a substantially increased risk of progression (HR=16.9, 95% CI: 7.4-38.3) and death (HR=7.8, 95% CI: 4.4-14.1) with an average overall survival of only 0.9 years. In summary, we found that at diagnosis a subset of MCL patients (14%) overexpressed MYC protein, and had a poor prognosis but that MYC rearrangements were rare. Tumors with concurrent MYC overexpression and TP53/p53 alterations pinpointed MCL patients with a dismal prognosis with a median overall survival of less than 3 years. We propose that MYC needs to be assessed beyond the current high-risk factors in MCL in order to identify cases in need of alternative treatment.

Overexpression of the key metabolic protein CPT1A defines mantle cell lymphoma patients with poor response to standard high-dose chemotherapy independent of MIPI and complement established highrisk factors.

The variable outcome to standard immunochemotherapy for mantle cell lymphoma (MCL) patients is a clinical challenge. Established risk factors, including high MCL International Prognostic Index (MIPI), high proliferation (Ki-67), non-classic (blastoid/pleomorphic) morphology, and mutated TP53, only partly identify patients in need of alternative treatment. Deepened understanding of biological factors that influence time to progression and relapse would allow for an improved stratification, and identification of novel targets for high-risk patients. We performed gene expression analyses to identify pathways and genes associated with outcome in a cohort of homogeneously treated patients. In addition to deregulated proliferation, we show that thermogenesis, fatty acid degradation and oxidative phosphorylation are altered in patients with poor survival, and that high expression of carnitine palmitoyltransferase 1A (CPT1A), an enzyme involved in fatty acid degradation, can specifically identify high-risk patients independent of the established high-risk factors. We suggest that complementary investigations of metabolism may increase the accuracy of patient stratification and that immunohistochemistry- based assessment of CPT1A can contribute to defining high-risk MCL.

Mixed Phenotype/Lineage Leukemia: Has Anything Changed for 2021 on Diagnosis, Classification, and Treatment?

PURPOSE OF REVIEW: Recent advances in the small field of the rare mixed phenotype acute leukemias (MPAL) are presented focusing on a better understanding of their pathophysiology and search for better therapeutic approaches. RECENT FINDINGS: Three aspects of respective classification, therapy, and immunophenotype of MPAL are reviewed. New proposals have been made to segregate MPAL subtypes based on their genomic landscape. In parallel, it was found that a large array of therapeutic approaches has been tested in the past few years with increasingly good results. Finally, we explored the use of unsupervised flow cytometry analysis to dissect subtle variations in markers expression to better characterize the variegating aspect of MPALs. Genomic and immunophenotypic aspects more clearly link MPAL subtypes with bona fide acute myeloblastic of lymphoblastic leukemias. This is likely to impact therapeutic strategies, towards a better management and outcome.

Infiltration of CD163-, PD-L1- and FoxP3-positive cells adversely affects outcome in patients with mantle cell lymphoma independent of established risk factors.

We characterised patients with mantle cell lymphoma (MCL) with poor prognosis based on differences in immune infiltration. Different expressions of the tumour cell markers Cyclin D1 and sex-determining region Y-box transcription factor 11 (SOX11), and the immune markers cluster of differentiation 3 (CD3), CD4, CD8, CD25, forkhead box protein P3 (FoxP3), T-box transcription factor TBX21 (T-bet), programmed cell death protein 1 (PD-1), programmed-death ligand 1 (PD-L1) and CD163 were investigated for all-cause mortality in 282 patients with MCL and time-to-progression (TTP) in 106 clinical trial patients. With increasing age, a significantly lower infiltration of CD3+ T lymphocytes was seen. T-cell infiltration was independent of cellular tumour antigen p53 (p53) expression, Ki-67, morphology and frequency of tumour cells. The all-cause mortality was higher in patients with PD-L1-expression above cut-off [hazard ratio (HR) 1·97, 95% confidence interval (CI) 1·18-3·25, adjusted for sex and MCL International Prognostic Index (MIPI)] and a higher frequency of CD163+ cells (continuously, HR 1·51, 95% CI 1·03-2·23, adjusting for age, sex, morphology, Ki-67 and p53). In patients treated within the Nordic Lymphoma Group MCL2/3 trials, TTP was shorter in patients with a higher frequency of FoxP3+ cells (HR 3·22, 95% CI 1·40-7·43) and CD163+ cells (HR 6·09, 95% CI 1·84-20·21), independent of sex and MIPI. When combined a higher frequency of CD163+ macrophages and PD-L1+ cells or high CD163+ macrophages and FoxP3+ regulatory T cells indicated worse outcome independent of established risk factors. The T-cell infiltrate was in turn independent of molecular characteristics of the malignant cells and decreased with age.

Monitoring treatment with 5-Azacitidine by flow cytometry predicts duration of hematological response in patients with myelodysplastic syndrome.

5-Azacitidine (AZA) therapy is used in high-risk myelodysplastic syndrome (MDS) patients who often show abnormalities in their immunophenotype. We explored the potential impact of AZA on these immunophenotypic abnormalities in serial bone marrow studies performed in 81 patients from five centers. We compared the immunophenotypic features before and after therapy with AZA, established definitions consistent with flow cytometry immunophenotyping (FCI) improvement, and explored its clinical significance. After a median of 6 cycles of AZA, 41% of patients showed a FCI improvement and this finding associated with best possible clinical response (P < 0.001). FCI improvement also correlated with hematological improvement (HI) (53/78 patients; 68%), independently of their eligibility for stem cell transplantation. Among patients who achieved a HI after 6 cycles of AZA, the probability of maintaining this response at 12 cycles of AZA was twice as large (67%) for those patients who also achieved a FCI improvement after 6 cycles of AZA as compared to patients who did not (33%, P < 0.01). These findings support that monitoring of the immunophenotypic abnormalities during therapy with AZA may assist in redefining the quality of response in patients with MDS.

Cumulative exposure to melphalan chemotherapy and subsequent risk of developing acute myeloid leukemia and myelodysplastic syndromes in patients with multiple myeloma.

OBJECTIVES: The aim of this study was to determine risk factors for development of acute myeloid leukemia/myelodysplastic syndromes (AML/MDS) in patients with multiple myeloma (MM). METHODS: We identified all patients diagnosed with MM in Sweden from January 1st, 1958 to December 31, 2011. A total of 26 627 patients were diagnosed with MM with during the study period. Of these, 124 patients (0.5%) developed subsequent AML/MDS. For each patient with MM and a subsequent AML/MDS diagnosis, we randomly selected a matched (age, sex, and date of MM diagnosis) MM patient without a subsequent second malignancy diagnosis. RESULTS: The cumulative melphalan exposure was significantly higher (OR = 2.8, 95% CI 1.7-5.2; P < .001) among cases (median 988 mg; IQR 644-1640) compared with controls (median 578 mg; IQR 360-967). Median time to AML/MDS development was 3.8 years (IQR 2.8-5.8). Risk of AML/MDS was not statistically altered by M protein isotype, anemia, renal failure, hypercalcemia, lytic bone lesions, or radiation therapy. CONCLUSION: In this nationwide population-based study, we show that increased cumulative doses of alkylating therapy with melphalan increases the subsequent risk of developing AML/MDS in patients with MM. Given improved survival in MM patients over the last decade future studies will be important to better define long-term risks.

p53 is associated with high-risk and pinpoints TP53 missense mutations in mantle cell lymphoma.

Survival for patients diagnosed with mantle cell lymphoma (MCL) has improved drastically in recent years. However, patients carrying mutations in tumour protein p53 (TP53) do not benefit from modern chemotherapy-based treatments and have poor prognosis. Thus, there is a clinical need to identify missense mutations through routine analysis to enable patient stratification. Sequencing is not widely implemented in clinical practice for MCL, and immunohistochemistry (IHC) is a feasible alternative to identify high-risk patients. The aim of the present study was to investigate the accuracy of p53 as a tool to identify patients with TP53 missense mutations and the prognostic impact of overexpression and mutations in a Swedish population-based cohort. In total, 317 cases were investigated using IHC and 255 cases were sequenced, enabling analysis of p53 and TP53 status among 137 cases divided over the two-cohort investigated. The accuracy of predicting missense mutations from protein expression was 82%, with sensitivity at 82% and specificity at 100% in paired samples. We further show the impact of p53 expression and TP53 mutations on survival (hazard ratio of 3·1 in univariate analysis for both), and the association to risk factors, such as high MCL International Prognostic Index, blastoid morphology and proliferation, in a population-based setting.

Proteomic Profiling of Diffuse Large B-Cell Lymphomas.

OBJECTIVE: The aim of this study was to identify differences in proteome profiles of diffuse large B-cell lymphoma (DLBCL) of nongerminal center (non-GC) versus GC type in the search for new markers and drug targets. METHODS: Six DLBCL, with 3 repeats for each, were used for the initial study by proteomics: 3 non-GC and 3 GC DLBCL cases. For immunohistochemistry, tissue microarrays were made from 31 DLBCL samples: 16 non-GC de novo lymphomas and 15 GC cases (11 transformed from follicular lymphomas and 4 de novo GC lymphomas). Proteome profiling was performed by two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry. RESULTS: Ninety-one proteins were found differentially expressed in non-GC compared to GC type. The Cytoscape tool was used for systemic analysis of proteomics data, revealing 19 subnetworks representing functions affected in non-GC versus GC types of DLBCL. CONCLUSION: A validation study of 3 selected proteins (BiP/Grp78, Hsp90, and cyclin B2) showed the enhanced expression in non-GC DLBCL, supporting the proteomics data.

Immunophenotypic analysis of erythroid dysplasia in myelodysplastic syndromes. A report from the IMDSFlow working group.

Current recommendations for diagnosing myelodysplastic syndromes endorse flow cytometry as an informative tool. Most flow cytometry protocols focus on the analysis of progenitor cells and the evaluation of the maturing myelomonocytic lineage. However, one of the most frequently observed features of myelodysplastic syndromes is anemia, which may be associated with dyserythropoiesis. Therefore, analysis of changes in flow cytometry features of nucleated erythroid cells may complement current flow cytometry tools. The multicenter study within the IMDSFlow Working Group, reported herein, focused on defining flow cytometry parameters that enable discrimination of dyserythropoiesis associated with myelodysplastic syndromes from non-clonal cytopenias. Data from a learning cohort were compared between myelodysplasia and controls, and results were validated in a separate cohort. The learning cohort comprised 245 myelodysplasia cases, 290 pathological, and 142 normal controls; the validation cohort comprised 129 myelodysplasia cases, 153 pathological, and 49 normal controls. Multivariate logistic regression analysis performed in the learning cohort revealed that analysis of expression of CD36 and CD71 (expressed as coefficient of variation), in combination with CD71 fluorescence intensity and the percentage of CD117+ erythroid progenitors provided the best discrimination between myelodysplastic syndromes and non-clonal cytopenias (specificity 90%; 95% confidence interval: 84-94%). The high specificity of this marker set was confirmed in the validation cohort (92%; 95% confidence interval: 86-97%). This erythroid flow cytometry marker combination may improve the evaluation of cytopenic cases with suspected myelodysplasia, particularly when combined with flow cytometry assessment of the myelomonocytic lineage.

Issues in diagnosis of small B cell lymphoid neoplasms involving the bone marrow and peripheral blood. Report on the Bone Marrow Workshop of the XVIIth meeting of the European Association for Haematopathology and the Society for Hematopathology.

Small B cell lymphoid neoplasms are the most common lymphoproliferative disorders involving peripheral blood (PB) and bone marrow (BM). The Bone Marrow Workshop (BMW) organized by the European Bone Marrow Working Group (EBMWG) of the European Association for Haematopathology (EAHP) during the XVIIth EAHP Meeting in Istanbul, October 2014, was dedicated to discussion of cases illustrating how the recent advances in immunophenotyping, molecular techniques and cytogenetics provide better understanding and classification of these entities. Submitted cases were grouped into following categories: (i) cases illustrating diagnostic difficulties in chronic lymphocytic leukaemia (CLL); (ii) cases of BM manifestations of small B cell lymphoid neoplasms other than CLL; (iii) transformation of small B cell lymphoid neoplasms in the BM; and (iv) multiclonality and composite lymphomas in the BM. This report summarizes presented cases and conclusions of the BMW and provides practical recommendations for classification of the BM manifestations of small B cell lymphoid neoplasms based on the current state of knowledge.

Blastic plasmacytoid dendritic cell neoplasm with leukemic presentation: 10-Color flow cytometry diagnosis and HyperCVAD therapy.

Few studies describe the comprehensive immunophenotypic pattern of blastic plasmacytoid dendritic cell neoplasm (BPDCN) in the bone marrow and its treatment. This retrospective analysis evaluates the diagnostic flow cytometry (FCM) pattern and outcome of nine patients diagnosed with BPDCN. A four-tube 10-color FCM panel used for diagnosis of acute leukemia (AL), showed cells in the blast gate (CD45dim/low SSC) and were positive for CD4(bright), CD33(dim), CD56(heterogenous), CD123(bright), CD36, CD38, HLA-DR, CD71. Seven patients received front-line induction therapy with HyperCVAD with an overall response rate of 86%. Five of six responders underwent planned allogeneic hematopoietic cell transplantation (allo-HCT). For a median follow up of 13.3 months, the 1-year disease free survival and overall survival were 56 and 67%, respectively. An accurate diagnosis of BPDCN can be made by 10-color FCM using a four-tube AL panel demonstrating a characteristic pattern of antigen expression. Front-line induction chemotherapy with HyperCVAD can yield high remission rates, but allo-HCT is required for long-term durable remissions.

Detection of central nervous system involvement in childhood acute lymphoblastic leukemia by cytomorphology and flow cytometry of the cerebrospinal fluid.

BACKGROUND: Therapy directed at the central nervous system (CNS) is an essential part of the treatment for childhood acute lymphoblastic leukemia (ALL). The current evaluation of CNS involvement based on cytomorphological examination of the cerebrospinal fluid (CSF) alone is not as sensitive with low cell counts as flow cytometric immunophenotyping (FCI) of the CSF. However, the importance of low CSF blasts counts at diagnosis is uncertain. We sought to determine the significance of FCI in relation to conventional morphological examination. PROCEDURE: We retrospectively compared FCI of the CSF with cytomorphology at diagnosis or relapse of childhood ALL. All patients were diagnosed 2000-2012 in Stockholm or Umeå, Sweden. Clinical data were collected from medical records and the Nordic leukemia registry. Treatment assignment was based on morphological examination only. RESULTS: The cohort was comprised of 214 patients with ALL. CSF involvement was detected by both methods in 20 patients, in 17 by FCI alone, and in one patient by cytomorphology alone. The relapse rate was higher for patients with negative cytology but positive FCI compared to those without CNS involvement using both methods. The difference was especially marked in the current protocol. However, none of the patients with negative CSF cytology but positive FCI had a CNS relapse. CONCLUSIONS: FCI of the CSF increased the detection rate of CNS involvement of ALL approximately two times compared to cytomorphology. Patients with low-level CNS involvement may benefit from additional intensified systemic or CNS-directed therapy, but larger studies are needed.

Amplification of 2p as a genomic marker for transformation in lymphoma.

To outline further genetic mechanisms of transformation from follicular lymphoma (FL) to diffuse large B-cell lymphoma (DLBCL), we have performed whole genome array-CGH in 81 tumors from 60 patients [29 de novo DLBCL (dnDLBCL), 31 transformed DLBCL (tDLBCL), and 21 antecedent FL]. In 15 patients, paired tumor samples (primary FL and a subsequent tDLBCL) were available, among which three possessed more than two subsequent tumors, allowing us to follow specific genetic alterations acquired before, during, and after the transformation. Gain of 2p15-16.1 encompassing, among others, the REL, BCL11A, USP34, COMMD1, and OTX1 genes was found to be more common in the tDLBCL compared with dnDLBCL (P < 0.001). Furthermore, a high-level amplification of 2p15-16.1 was also detected in the FL stage prior to transformation, indicating its importance during the transformation event. Quantitative real-time PCR showed a higher level of amplification of REL, USP34, and COMMD1 (all involved in the NFκΒ-pathway) compared with BCL11A, which indicates that the altered genes disrupting the NFκΒ pathway may be the driver genes of transformation rather than the previously suggested BCL11A. Moreover, a 17q21.33 amplification was exclusively found in tDLBCL, never in FL (P < 0.04) or dnDLBCL, indicating an upregulation of genes of importance during the later phase of transformation. Taken together, our study demonstrates potential genomic markers for disease progression to clinically more aggressive forms. We also confirm the importance of the TP53-, CDKN2A-, and NFκΒ-pathways for the transformation from FL to DLBCL.

Dendritic cells in bone marrow at diagnosis and after chemotherapy in adult patients with acute myeloid leukaemia.

Dendritic cells (DCs) develop in the bone marrow from haematopoietic progenitor cells. Two subsets, plasmacytoid DCs (pDCs) and myeloid DCs (mDCs), have been identified. Little is known regarding DC levels in bone marrow of patients with acute myeloid leukaemia (AML) before and after chemotherapy. We investigated relative pDC and mDC levels in bone marrow from 37 hospital controls and 60 patients with AML [at diagnosis, complete remission (CR) and follow-up] using four-colour flow cytometry. The pDC immunophenotype was characterized as lin-/HLA-DR+/CD123 +  and mDC as lin-/HLA-DR+/CD11c+. In 69% of patients with AML, no DCs were detected at diagnosis. At CR, mDC levels were the same in patients with AML and hospital controls while pDC levels were slightly lower. There was no association between minimal residual disease or survival rates and DC levels. Patients with low mDC levels at CR were more likely to suffer from complicated infections, although the difference was not statistically significant. Altogether, there was a profound decrease in DC levels in patients with AML at diagnosis. DC levels increased at CR and were higher than in hospital controls after post-remission therapy, suggesting that DCs recover after repeated chemotherapy. There may be an association between mDC levels and infectious complications.

p53 protein expression independently predicts outcome in patients with lower-risk myelodysplastic syndromes with del(5q).

Del(5q) myelodysplastic syndromes defined by the International Prognostic Scoring System as low- or intermediate-1-risk (lower-risk) are considered to have an indolent course; however, recent data have identified a subgroup of these patients with more aggressive disease and poorer outcomes. Using deep sequencing technology, we previously demonstrated that 18% of patients with lower-risk del(5q) myelodysplastic syndromes carry TP53 mutated subclones rendering them at higher risk of progression. In this study, bone marrow biopsies from 85 patients treated with lenalidomide in the MDS-004 clinical trial were retrospectively assessed for p53 expression by immunohistochemistry in association with outcome. Strong p53 expression in ≥ 1% of bone marrow progenitor cells, observed in 35% (30 of 85) of patients, was significantly associated with higher acute myeloid leukemia risk (P=0.0006), shorter overall survival (P=0.0175), and a lower cytogenetic response rate (P=0.009), but not with achievement or duration of 26-week transfusion independence response. In a multivariate analysis, p53-positive immunohistochemistry was the strongest independent predictor of transformation to acute myeloid leukemia (P=0.0035). Pyrosequencing analysis of laser-microdissected cells with strong p53 expression confirmed the TP53 mutation, whereas cells with moderate expression predominantly had wild-type p53. This study validates p53 immunohistochemistry as a strong and clinically useful predictive tool in patients with lower-risk del(5q) myelodysplastic syndromes. This study was based on data from the MDS 004 trial (clinicaltrials.gov identifier: NCT00179621).

The role of diagnostic tissue in research.

There are two broad classes (or categories) of excised human tissue: diagnostic tissue (DT) and research tissue (RT). Classification of excised human tissue does not define its ultimate use and ultimate use of excised human tissue does not define its classification. While both DT and RT can be used for research, DT has specific requirements with respect to how it must be handled if and when being accessed for research. We highlight distinguishing features of DT: (1) it is a clinical record, (2) it must be identifiable to a specific individual, (3) it is stewarded by pathology departments/clinical laboratories and (4) it has a mandatory retention period. We discuss how the further sub-classification of DT into archived DT (aDT) and excess DT (eDT) impacts the nature of its role in research. We examine the concept of DT as a clinical record and emphasize the impact of mandatory retention as it applies to how DT may be accessed for research purposes. We explain the role of post-retention eDT as a source of RT as well as procedures for access to in-retention aDT for research. Clarity of such issues will facilitate responsible access to DT for research.