A population-based study of transformed marginal zone lymphoma:identifying outcome-related characteristics

Histological transformation of marginal zone lymphoma (tMZL) into diffuse large B-cell lymphoma is associated with poor outcomes. Clinical characteristics associated with transformation risk and outcome after transformation are largely unknown due to scarcity of data. In this population-based study, competing risk analyses were performed to elucidate clinical characteristics associated with developing transformation among 1793 MZL patients using the Netherlands Cancer Registry. Cox regression analyses were performed to elucidate clinical characteristics associated with risk of relapse and mortality after transformation. Transformation occurred in 75 (4%) out of 1793 MZL patients. Elevated LDH and nodal MZL subtype at MZL diagnosis were associated with an increased risk, and radiotherapy with a reduced risk of developing tMZL. Most tMZL patients received R-(mini)CHOP (n = 53, 71%). Age &gt;60 years and (immuno)chemotherapy before transformation were associated with an increased risk of relapse and mortality after transformation. Two-year progression-free survival (PFS) and overall survival (OS) were 66% (95% CI 52-77%) and 75% (95% CI 62-85%) for R-(mini)CHOP-treated tMZL patients, as compared to a PFS and OS both of 41% (95% CI 19-63%) for patients treated otherwise. Our study offers comprehensive insights into characteristics associated with transformation and survival after transformation, thereby optimizing guidelines and patient counseling.</p

Cell-of-origin classification using the Hans and Lymph2Cx algorithms in primary cutaneous large B-cell lymphomas

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) and primary cutaneous follicle center lymphoma with a diffuse population of large cells (PCFCL-LC) are both primary cutaneous B-cell lymphomas with large-cell morphology (CLBCL) but with different clinical characteristics and behavior. In systemic diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS), gene-expression profiling (GEP) revealed two molecular subgroups based on their cell-of-origin (COO) with prognostic significance: the germinal center B-cell-like (GCB) subtype and the activated B-cell-like (ABC) subtype. This study investigated whether COO classification is a useful tool for classification of CLBCL. For this retrospective study, 51 patients with PCDLBCL-LT and 15 patients with PCFCL-LC were analyzed for their COO according to the immunohistochemistry-based Hans algorithm and the NanoString GEP-based Lymph2Cx algorithm. In PCFCL-LC, all cases (100%) classified as GCB by both Hans and Lymph2Cx. In contrast, COO classification in PCDLBCL-LT was heterogeneous. Using Hans, 75% of the PCDLBCL-LT patients classified as non-GCB and 25% as GCB, while Lymph2Cx classified only 18% as ABC, 43% as unclassified/intermediate, and 39% as GCB. These COO subgroups did not differ in the expression of BCL2 and IgM, mutations in MYD88 and/or CD79B, loss of CDKN2A, or survival. In conclusion, PCFCL-LC uniformly classified as GCB, while PCDLBCL-LT classified along the COO spectrum of DLBCL-NOS using the Hans and Lymph2Cx algorithms. In contrast to DLBCL-NOS, the clinical relevance of COO classification in CLBCL using these algorithms has limitations and cannot be used as an alternative for the current multiparameter approach in differentiation of PCDLBCL-LT and PCFCL-LC

Chromothripsis is a common mechanism driving genomic rearrangements in primary and metastatic colorectal cancer

ABSTRACT: BACKGROUND: Structural rearrangements form a major class of somatic variation in cancer genomes. Local chromosome shattering, termed chromothripsis, is a mechanism proposed to be the cause of clustered chromosomal rearrangements and was recently described to occur in a small percentage of tumors. The significance of these clusters for tumor development or metastatic spread is largely unclear. RESULTS: We used genome-wide long mate-pair sequencing and SNP array profiling to reveal that chromothripsis is a widespread phenomenon in primary colorectal cancer and metastases. We find large and small chromothripsis events in nearly every colorectal tumor sample and show that several breakpoints of chromothripsis clusters and isolated rearrangements affect cancer genes, including NOTCH2, EXO1 and MLL3. We complemented the structural variation studies by sequencing the coding regions of a cancer exome in all colorectal tumor samples and found somatic mutations in 24 genes, including APC, KRAS, SMAD4 and PIK3CA. A pairwise comparison of somatic variations in primary and metastatic samples indicated that many chromothripsis clusters, isolated rearrangements and point mutations are exclusively present in either the primary tumor or the metastasis and may affect cancer genes in a lesion-specific manner. CONCLUSIONS: We conclude that chromothripsis is a prevalent mechanism driving structural rearrangements in colorectal cancer and show that a complex interplay between point mutations, simple copy number changes and chromothripsis events drive colorectal tumor development and metastasis.

Outcomes of rare patients with a primary cutaneous CD30(+) lymphoproliferative disorder developing extracutaneous disease

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Impact of rituximab biosimilars on overall survival in diffuse large B-cell lymphoma:a Dutch population-based study

In 2017, the European Medicines Agency approved rituximab biosimilars (R-biosimilars) for treatment of diffuse large B-cell lymphoma (DLBCL). Thereafter, the Netherlands was one of the first countries to implement R-biosimilars, given lower costs compared with rituximab originator (R-originator). This study's objective was to investigate whether overall survival (OS) of patients with DLBCL receiving R-biosimilars is similar to patients treated with R-originator. DLBCL patients ≥18 years, diagnosed between 2014 and 2018, who received at least 1 cycle of rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) were identified in the Netherlands Cancer Registry. Patients were categorized into R-originator or R-biosimilars groups based on data from a central repository of the Dutch medicinal drug market. The primary end point was 3-year OS, defined as the time between diagnosis and all-cause death. By the end of 2018, 91% of purchased rituximab were biosimilars. In total, 4429 patients were identified with 876 in the R-biosimilars group and 3553 in the R-originator group. Patients in the R-biosimilars group less frequently received .6 cycles of R-CHOP compared with patients treated with R-originator (24% vs 30%, P 5 .003). The 3-year OS did not differ between patients treated with R-originator or R-biosimilars (73% vs 73%, P = .855). This was confirmed with a multivariable Cox regression analysis accounting for sex, age, International Prognostic Index score, and number of R-CHOP cycles. In conclusion, the 3-year OS is similar for patients treated with CHOP in combination with R-originator or R-biosimilars and, therefore, favors the use of R-biosimilars in DLBCL treatment management

Low Mutational Burden of Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue in Patients with Primary Sjogren's Syndrome

SIMPLE SUMMARY: Patients with primary Sjogren’s syndrome (pSS) are at risk of developing extranodal marginal zone lymphoma (ENMZL) of the mucosa-associated lymphoid tissue (MALT) in the parotid glands. The genetic mechanism underlying development of MALT lymphoma in the context of pSS is unknown. The aim of our study was to define the genomic landscape of pSS-associated MALT lymphoma. For 17 localized pSS-associated MALT lymphomas, we analyzed the presence of nonsynonymous mutations, copy number alterations (CNAs) and MALT1 translocations. pSS-associated MALT lymphomas were characterized by a low mutational load (median number of nonsynonymous somatic variants per case was 7, range 2–78) and a limited number of CNAs. Unlike the recurrent genomic aberrations observed in MALT lymphoma, which were not associated with pSS, pSS-associated MALT lacked a clear lymphoma-related profile. The data suggest that localized pSS-associated MALT lymphomas are a distinct type of ENMZL, which are genomically stable and most likely depend on a stimulatory micro-environment. ABSTRACT: Patients with primary Sjogren’s syndrome (pSS) are at risk of developing extranodal marginal zone lymphoma (ENMZL) of the mucosa-associated lymphoid tissue (MALT) in the parotid glands. Unlike recurrent genomic aberrations observed in MALT lymphoma, which were not associated with pSS (non-pSS), it is unknown which somatic aberrations underlie the development of pSS-associated MALT lymphomas. Whole-exome sequencing was performed on 17 pSS-associated MALT lymphomas. In total, 222 nonsynonymous somatic variants affecting 182 genes were identified across the 17 cases. The median number of variants was seven (range 2–78), including three cases with a relatively high mutational load (≥24/case). Out of 16 recurrently mutated genes, ID3, TBL1XR1, PAX5, IGLL5 and APC are known to be associated with lymphomagenesis. A total of 18 copy number alterations were detected in eight cases. MALT1 translocations were not detected. With respect to outcome, only two cases relapsed outside of the salivary glands. Both had a high mutational load, suggesting a more advanced stage of lymphoma. The low mutational load and lack of a clear lymphoma-related mutation profile suggests that localized pSS-associated MALT lymphomas are genomically more stable than non-pSS MALT lymphomas and most likely depend on a stimulatory micro-environment

Biological and Clinical Implications of Gene-Expression Profiling in Diffuse Large B-Cell Lymphoma:A Proposal for a Targeted BLYM-777 Consortium Panel as Part of a Multilayered Analytical Approach

Gene-expression profiling (GEP) is used to study the molecular biology of lymphomas. Here, advancing insights from GEP studies in diffuse large B-cell lymphoma (DLBCL) lymphomagenesis are discussed. GEP studies elucidated subtypes based on cell-of-origin principles and profoundly changed the biological understanding of DLBCL with clinical relevance. Studies integrating GEP and next-generation DNA sequencing defined different molecular subtypes of DLBCL entities originating at specific anatomical localizations. With the emergence of high-throughput technologies, the tumor microenvironment (TME) has been recognized as a critical component in DLBCL pathogenesis. TME studies have characterized so-called “lymphoma microenvironments" and “ecotypes”. Despite gained insights, unexplained chemo-refractoriness in DLBCL remains. To further elucidate the complex biology of DLBCL, we propose a novel targeted GEP consortium panel, called BLYM-777. This knowledge-based biology-driven panel includes probes for 777 genes, covering many aspects regarding B-cell lymphomagenesis (f.e., MYC signature, TME, immune surveillance and resistance to CAR T-cell therapy). Regarding lymphomagenesis, upcoming DLBCL studies need to incorporate genomic and transcriptomic approaches with proteomic methods and correlate these multi-omics data with patient characteristics of well-defined and homogeneous cohorts. This multilayered methodology potentially enhances diagnostic classification of DLBCL subtypes, prognostication, and the development of novel targeted therapeutic strategies. Simple Summary: This review summarizes gene-expression profiling insights into the background and origination of diffuse large B-cell lymphomas (DLBCL). To further unravel the molecular biology of these lymphomas, a consortium panel called BLYM-777 was designed including genes important for subtype classifications, genetic pathways, tumor-microenvironment, immune response and resistance to targeted therapies. This review proposes to combine this transcriptomic method with genomics, proteomics, and patient characteristics to facilitate diagnostic classification, prognostication, and the development of new targeted therapeutic strategies in DLBCL

IGLV3-21*01 is an inherited risk factor for CLL through the acquisition of a single-point mutation enabling autonomous BCR signaling

The prognosis of chronic lymphocytic leukemia (CLL) depends on different markers, including cytogenetic aberrations, oncogenic mutations, and mutational status of the immunoglobulin (Ig) heavy-chain variable (IGHV) gene. The number of IGHV mutations distinguishes mutated (M) CLL with a markedly superior prognosis from unmutated (UM) CLL cases. In addition, B cell antigen receptor (BCR) stereotypes as defined by IGHV usage and complementarity-determining regions (CDRs) classify ∼30% of CLL cases into prognostically important subsets. Subset 2 expresses a BCR with the combination of IGHV3-21-derived heavy chains (HCs) with IGLV3-21-derived light chains (LCs), and is associated with an unfavorable prognosis. Importantly, the subset 2 LC carries a single-point mutation, termed R110, at the junction between the variable and constant LC regions. By analyzing 4 independent clinical cohorts through BCR sequencing and by immunophenotyping with antibodies specifically recognizing wild-type IGLV3-21 and R110-mutated IGLV3-21 (IGLV3-21R110), we show that IGLV3-21R110-expressing CLL represents a distinct subset with poor prognosis independent of IGHV mutations. Compared with other alleles, only IGLV3-21*01 facilitates effective homotypic BCR-BCR interaction that results in autonomous, oncogenic BCR signaling after acquiring R110 as a single-point mutation. Presumably, this mutation acts as a standalone driver that transforms IGLV3-21*01-expressing B cells to develop CLL. Thus, we propose to expand the conventional definition of CLL subset 2 to subset 2L by including all IGLV3-21R110-expressing CLL cases regardless of IGHV mutational status. Moreover, the generation of monoclonal antibodies recognizing IGLV3-21 or mutated IGLV3-21R110 facilitates the recognition of B cells carrying this mutation in CLL patients or healthy donors

A significant proportion of classic Hodgkin lymphoma recurrences represents clonally unrelated second primary lymphoma

Despite high cure rates in classic Hodgkin lymphoma (cHL), relapses are observed. Whether relapsed cHL represents second primary lymphoma or an underlying T-cell lymphoma (TCL) mimicking cHL is under-investigated. To analyze the nature of cHL recurrences, in-depth clonality testing of immunoglobulin (IG) and T-cell receptor (TR) rearrangements was performed in paired cHL diagnosis and recurrences of 60 patients, supported by targeted mutation analysis of lymphoma-associated genes. Clonal IG rearrangements were detected by next-generation sequencing (NGS) in 69/120 (58%) diagnosis and recurrence samples. The clonal relationship could be established in 34 cases, identifying clonally related relapsed cHL in 24/34 patients (71%). Clonally unrelated cHL was observed in 10/34 patients (29%) as determined by IG-NGS clonality assessment, and confirmed by the identification of predominantly mutually exclusive gene mutations in the paired cHL samples. In recurrences of &gt;2 years, ~60% of cHL patients for which the clonal relationship could be established showed a second primary cHL. Clonal TR gene rearrangements were identified in 14/125 samples (11%), and TCL-associated gene mutations were detected in 7/14 samples. Retrospective pathology review with integration of the molecular findings were consistent with an underlying TCL in 5 patients aged &gt;50 years. This study shows that cHL recurrences, especially after 2 years, sometimes represent a new primary cHL or TCL mimicking cHL, as uncovered by NGS-based IG/TR clonality testing and gene mutation analysis. Given the significant therapeutic consequences, molecular testing of a presumed relapse in cHL is crucial for subsequent appropriate treatment strategies adapted to the specific lymphoma presentation.</p