Gene alterations in epigenetic modifiers and JAK-STAT signaling are frequent in breast implant-associated ALCL

Breast implant surface topography triggers a chronic-like inflammatory response

Breast implants are extensively employed for both reconstructive and esthetic purposes. However, the safety of breast implants with textured surfaces has been questioned, owing to a potential correlation with anaplastic large-cell lymphoma and the recurrence of breast cancer. This study investigates the immune response elicited by different prosthetic surfaces, focusing on the comparison between macrotextured and microtextured breast implants. Through the analysis of intraoperatively harvested periprosthetic fluids and cell culture experiments on surface replicas, we demonstrate that macrotextured surfaces elicit a more pronounced chronic-like activation of leucocytes and an increased release of inflammatory cytokines, in contrast to microtextured surfaces. In addition, in vitro fluorescent imaging of leucocytes revealed an accumulation of lymphocytes within the cavities of the macrotextured surfaces, indicating that the physical entrapment of these cells may contribute to their activation. These findings suggest that the topography of implant surfaces plays a significant role in promoting a chronic-like inflammatory environment, which could be a contributing factor in the development of lymphomas associated with a wide range of implantable devices.

What is new in the classification of peripheral T cell lymphomas?

In this review focus article, we highlight the main modifications introduced in the latest 2022 International Consensus Classification and World Health Organization classification (ICC and WHO-HAEM5) of mature T (and NK) cell neoplasms (PTCLs) and consequent implications for diagnostic practice. The changes result from recent advances in the genomic and molecular characterization of PTCLs and enhanced understanding of their pathobiology. Specifically, consideration is given to the following groups of diseases: Epstein-Barr virus (EBV)-associated neoplasms; follicular helper T cell lymphoma; anaplastic large cell lymphomas; primary intestinal T and NK cell lymphomas and lymphoproliferative disorders; and PTCL, not otherwise specified.

The implication of next-generation sequencing in the diagnosis and clinical management of non-Hodgkin lymphomas

Next generation sequencing (NGS) is a technology that broadens the horizon of knowledge of several somatic pathologies, especially in oncological and oncohematological pathology. In the case of NHL, the understanding of the mechanisms of tumorigenesis, tumor proliferation and the identification of genetic markers specific to different lymphoma subtypes led to more accurate classification and diagnosis. Similarly, the data obtained through NGS allowed the identification of recurrent somatic mutations that can serve as therapeutic targets that can be inhibited and thus reducing the rate of resistant cases. The article's purpose is to offer a comprehensive overview of the best ways of integrating of next-generation sequencing technologies for diagnosis, prognosis, classification, and selection of optimal therapy from the perspective of tailor-made medicine.

Implant replacement and anaplastic large cell lymphoma associated with breast implants: a quantitative analysis

Introduction

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a rare form of non-Hodgkin T-cell lymphoma associated with breast reconstruction post-mastectomy or cosmetic-additive mammoplasty. The increasing use of implants for cosmetic purposes is expected to lead to an increase in BIA-ALCL cases. This study investigated the main characteristics of the disease and the factors predicting BIA-ALCL onset in patients with and without an implant replacement.

Methods

A quantitative analysis was performed by two independent researchers on cases extracted from 52 primary studies (case report, case series, and systematic review) published until April 2022 and searched in PubMed, Scopus, and Google-Scholar databases using "Breast-Implant" AND/OR "Associated" AND/OR "Anaplastic-Large-Cell-Lymphoma". The statistical significance was verified by Student's t-test for continuous variables, while Fisher's exact test was applied for qualitative variables. Cox model with time-dependent covariates was used to estimate BIA-ALCL's onset time. The Kaplan-Meier model allowed the estimation of the probability of survival after therapy according to breast implant exposure time.

Results

Overall, 232 patients with BIA-ALCL were extracted. The mean age at diagnosis was 55 years old, with a mean time to disease onset from the first implant of 10.3 years. The hazard of developing BIA-ALCL in a shorter time resulted significantly higher for patients not having an implant replacement (hazard ratio = 0.03; 95%CI: 0.005-0.19; p-value < 0.01). Patients with implant replacement were significantly older than patients without previous replacement at diagnosis, having a median time to diagnosis since the first implant of 13 years (7 years in patients without replacement); anyway, the median time to BIA-ALCL occurrence since the last implantation was equal to 5 years.

Discussion

Our findings suggest that, in BIA-ALCL patients, the implant substitution and/or capsulectomy may delay the disease's onset. However, the risk of reoccurrence in an earlier time should be considered in these patients. Moreover, the time to BIA-ALCL onset slightly increased with age. Selection bias, lack of awareness, misdiagnosis, and limited data availability could be identified as limits of our study. An implant replacement should be considered according to a risk stratification approach to delay the BIA-ALCL occurrence in asymptomatic patients, although a stricter follow-up after the implant substitution should be recommended.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42023446726.

Updates in pathobiological aspects of anaplastic large cell lymphoma

Anaplastic large cell lymphomas (ALCL) encompass several distinct subtypes of mature T-cell neoplasms that are unified by the expression of CD30 and anaplastic cytomorphology. Identification of the cytogenetic abnormality t(2;5)(p23;q35) led to the subclassification of ALCLs into ALK+ ALCL and ALK- ALCL. According to the most recent World Health Organization (WHO) Classification of Haematolymphoid Tumours as well as the International Consensus Classification (ICC) of Mature Lymphoid Neoplasms, ALCLs encompass ALK+ ALCL, ALK- ALCL, and breast implant-associated ALCL (BI-ALCL). Approximately 80% of systemic ALCLs harbor rearrangement of ALK, with NPM1 being the most common partner gene, although many other fusion partner genes have been identified to date. ALK- ALCLs represent a heterogeneous group of lymphomas with distinct clinical, immunophenotypic, and genetic features. A subset harbor recurrent rearrangement of genes, including TYK2, DUSP22, and TP63, with a proportion for which genetic aberrations have yet to be characterized. Although primary cutaneous ALCL (pc-ALCL) is currently classified as a subtype of primary cutaneous T-cell lymphoma, due to the large anaplastic and pleomorphic morphology together with CD30 expression in the malignant cells, this review also discusses the pathobiological features of this disease entity. Genomic and proteomic studies have contributed significant knowledge elucidating novel signaling pathways that are implicated in ALCL pathogenesis and represent candidate targets of therapeutic interventions. This review aims to offer perspectives on recent insights regarding the pathobiological and genetic features of ALCL.

Cavity-based lymphomas: challenges and novel concepts. A report of the 2022 EA4HP/SH lymphoma workshop

The 2022 European Association for Haematopathology/Society for Hematopathology lymphoma workshop session on cavity-based lymphomas included sixty-eight cases in seven sections. The disease entities discussed include primary effusion lymphomas (PEL), extracavitary primary effusion lymphomas and confounding entities (ECPEL), HHV8-negative B-lineage lymphomas-effusion based (EBV-negative, EBV-positive, and plasmablastic types), diffuse large B-cell lymphoma associated with chronic inflammation, fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL), breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), and other lymphomas presenting as an effusion. All entities above are discussed; however, three are delved into greater detail given the challenges with classification: ECPEL, HHV8-negative effusion-based lymphomas, and FA-DLBCL. Cases exemplifying the diagnostic difficulty in differentiating ECPEL from HHV8-positive diffuse large B-cell lymphoma and germinotropic lymphoproliferative disorder were discussed. The more recently recognized effusion-based HHV8-negative large B-cell lymphoma is explored, with several cases submitted raising the question if this subset should be carved out as a specific entity, and if so, what should be the refining diagnostic criteria. Case submissions to the FA-DLBCL section yielded one of the largest case series to date, including classic cases, cases furthering the discussion on disease sites and prognosis, as well as novel concepts to be considered in this entity. The 2022 EA4HP/SH workshop cases allowed for further confirmation of the characteristics of some of the more historically accepted cavity-based lymphomas, as well as further inquiry and debate on relatively new or evolving entities.

Preclinical in vitro evaluation of implantable materials: conventional approaches, new models and future directions

Nowadays, implants and prostheses are widely used to repair damaged tissues or to treat different diseases, but their use is associated with the risk of infection, inflammation and finally rejection. To address these issues, new antimicrobial and anti-inflammatory materials are being developed. Aforementioned materials require their thorough preclinical testing before clinical applications can be envisaged. Although many researchers are currently working on new in vitro tissues for drug screening and tissue replacement, in vitro models for evaluation of new biomaterials are just emerging and are extremely rare. In this context, there is an increased need for advanced in vitro models, which would best recapitulate the in vivo environment, limiting animal experimentation and adapted to the multitude of these materials. Here, we overview currently available preclinical methods and models for biological in vitro evaluation of new biomaterials. We describe several biological tests used in biocompatibility assessment, which is a primordial step in new material's development, and discuss existing challenges in this field. In the second part, the emphasis is made on the development of new 3D models and approaches for preclinical evaluation of biomaterials. The third part focuses on the main parameters to consider to achieve the optimal conditions for evaluating biocompatibility; we also overview differences in regulations across different geographical regions and regulatory systems. Finally, we discuss future directions for the development of innovative biomaterial-related assays: in silico models, dynamic testing models, complex multicellular and multiple organ systems, as well as patient-specific personalized testing approaches.

The evaluation of the delayed swollen breast in patients with a history of breast implants

Breast implants, whether placed for reconstructive or cosmetic purposes, are rarely lifetime devices. Rupture, resulting from compromised implant shell integrity, and capsular contracture caused by constriction of the specialized scar tissue that normally forms around breast implants, have long been recognized, and remain the leading causes of implant failure. It is apparent, however, that women with breast implants may also experience delayed breast swelling due to a range of etiologic factors. While a majority of delayed seromas associated with breast implants have a benign etiology, this presentation cannot be ignored without an adequate workup as malignancies such as breast implant associated anaplastic large cell lymphoma (BIA-ALCL), breast implant associated diffuse large B-cell lymphoma (BIA-DLBCL), and breast implant associated squamous cell carcinoma (BIA-SCC) can have a similar clinical presentation. Since these malignancies occur with sufficient frequency, and with sometimes lethal consequences, their existence must be recognized, and an appropriate diagnostic approach implemented. A multidisciplinary team that involves a plastic surgeon, radiologist, pathologist, and, as required, surgical and medical oncologists can expedite judicious care. Herein we review and further characterize conditions that can lead to delayed swelling around breast implants.

How molecular advances may improve the diagnosis and management of PTCL patients

Peripheral T-cell lymphomas (PTCL) comprised more than 30 rare heterogeneous entities, representing 10 to 15% of adult non-Hodgkin lymphomas. Although their diagnosis is still mainly based on clinical, pathological, and phenotypic features, molecular studies have allowed for a better understanding of the oncogenic mechanisms involved and the refinement of many PTCL entities in the recently updated classifications. The prognosis remains poor for most entities (5-year overall survival < 30%), with current conventional therapies based on anthracyclin-based polychemotherapy regimen, despite many years of clinical trials. The recent use of new targeted therapies appears to be promising for relapsed/refractory patients, such as demethylating agents in T-follicular helper (TFH) PTCL. However further studies are needed to evaluate the proper combination of these drugs in the setting of front-line therapy. In this review, we will summarize the oncogenic events for the main PTCL entities and report the molecular targets that have led to the development of new therapies. We will also discuss the development of innovative high throughput technologies that aid the routine workflow for the histopathological diagnosis and management of PTCL patients.

Phosphorylated STAT3 as a potential diagnostic and predictive biomarker in ALK- ALCL vs. CD30high PTCL, NOS

Aims

The differential diagnosis between ALK-negative anaplastic large cell lymphoma (ALK- ALCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) with high expression of CD30 (CD30high) are essential. However, no reliable biomarker is available in daily practice except CD30. STAT3 is characteristically activated in ALCL. We aimed to investigate whether the status of STAT3 phosphorylation could help the differential diagnosis.

Methods

The status of phosphorylation of STAT3 was examined using two antibodies against pSTAT3-Y705 and pSTAT3-S727 by immunohistochemistry in ALK+ ALCL (n=33), ALK- ALCL (n=22) and PTCL, NOS (n=34). Ten PTCL, NOS with diffuse CD30 expression were defined as CD30high PTCL, NOS. Flowcytometric analysis were performed to evaluate the expression of pSTAT3-Y705/S727 in PTCL, NOS (n=3).

Results

The median H-scores of pSTAT3-Y705 and S727 were 280 and 260 in ALK+ ALCL, 250 and 240 in ALK- ALCL, and 45 and 75 in CD30high subgroup, respectively. Using H score of 145 as the cutoff value, pSTAT3-S727 alone distinguished between ALK- ALCL and CD30high PTCL, NOS with a sensitivity of 100% and specificity of 83%. Additionally, pSTAT3-S727, but not pSTAT3-Y705, was also expressed by background tumor-infiltrating lymphocytes (S727TILs) in PTCL, NOS. PTCL, NOS patients with high S727TILs H score had a favorable prognosis than those with no TILs (3-year OS rate: 43% vs. 0, p=0.013) or low S727TILs (3-year OS rate: 43% vs. 0, p=0.099). Flowcytometric analysis revealed that of the three patients investigated, two had enhanced pSTAT-S727 signals in neoplastic cell populations, and all three patients were negative for pSTAT3-Y705 expression in both tumor cells and background lymphocytes.

Conclusions

pSTAT3-Y705/S727 can be used to help distinguish ALK- ALCL from CD30high PTCL, NOS and pSTAT3-S727 expression by TILs predicts the prognosis of a subset of PTCL, NOS.

Breast Implant-Associated Tumors

In addition to anaplastic large T-cell lymphomas (BIA-ALCL), other implant-related tumors have been described for some years. Squamous cell carcinoma (SSC) and B-cell lymphomas occurred in very rare cases. The unexplained pathogenesis as well as the unclear individual risk profile is an ongoing source of uncertainty for patients and physicians. The pathogenesis of the tumors is still largely not understood. While BIA-ALCL occurs more frequently with textured breast implants, other tumors were also observed with smooth implants and at other implant sites. Multiple potential mechanisms are discussed. It is suspected that the etiology of a chronic inflammatory response and subsequently immunostimulation is multifactorial and appears to play a key role in the malignant transformation. Since there are currently no sufficiently valid data for a specific risk assessment, this must be done with caution. This article presents the incidence, pathogenesis, as well as the level of evidence according to the current state of knowledge, and evaluates and discusses the current literature.

Evaluation of Breast Implant-Associated Anaplastic Large Cell Lymphoma With Whole Exome and Genome Sequencing

BACKGROUND

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare malignancy originating from the periprosthetic capsule of a textured, most often macrotextured, breast implant. Identified in women whose indications for breast implants can be either aesthetic or reconstructive, the genomic underpinnings of this disease are only beginning to be elucidated.

OBJECTIVES

The aim of this study was to evaluate the exomes, and in some cases the entire genome, of patients with BIA-ALCL. Specific attention was paid to copy number alterations, chromosomal translocations, and other genomic abnormalities overrepresented in patients with BIA-ALCL.

METHODS

Whole-exome sequencing was performed on 6 patients, and whole-genome sequencing on 3 patients, with the Illumina NovaSeq 6000 sequencer. Data were analyzed with the Illumina DRAGEN Bio-IT Platform and the ChromoSeq pipeline. The Pathseq Genome Analysis Toolkit pipeline was used to detect the presence of microbial genomes in the sequenced samples.

RESULTS

Two cases with STAT3 mutations and 2 cases with NRAS mutations were noted. A critically deleted 7-Mb region was identified at the 11q22.3 region of chromosome 11, and multiple nonrecurrent chromosomal rearrangements were identified by whole-genome sequencing. Recurrent gene-level rearrangements, however, were not identified. None of the samples showed evidence of potential microbial pathogens.

CONCLUSIONS

Although no recurrent mutations were identified, this study identified mutations in genes not previously reported with BIA-ALCL or other forms of ALCL. Furthermore, not previously reported with BIA-ALCL, 11q22.3 deletions were consistent across whole-genome sequencing cases and present in some exomes.

LEVEL OF EVIDENCE: 5

Extranodal T- and NK-cell lymphomas

Non-cutaneous extranodal NK/T cell lymphoproliferations constitute a heterogenous group of rare neoplasms, occurring primarily in the gastro-intestinal tract, nasal area, spleen, and liver. Their nomenclature refers to their usual clinical presentation and predilection for specific anatomic sites-i.e. extranodal NK/T-cell lymphoma, nasal-type, hepatosplenic T-cell lymphoma, primary intestinal T-cell lymphomas, indolent lymphoproliferative disorders of the gastrointestinal tract, and breast implant-associated anaplastic large cell lymphoma. Extranodal tissues may also be involved by T-cell leukemias, or other entities usually presenting as nodal diseases. Primary extranodal entities range from indolent to highly aggressive diseases. Here, we will review the clinicopathologic features of the pertinent entities including the recent advances in their molecular and genetic characterization, with an emphasis on the changes introduced in the 2022 International Consensus Classification of lymphoid neoplasms, and highlight the diagnostic criteria helpful to sort out the distinction with potential mimickers.

Classification and challenges in the histopathological diagnosis of peripheral T-cell lymphomas, emphasis on the WHO-HAEM5 updates

Mature T-cell lymphomas represent neoplastic expansions of T-cell lymphocytes with a post-thymic derivation. Most of these tumors feature aggressive clinical behavior and challenging histopathological diagnosis and classification. Novel findings in the genomic landscape of T-cell lymphomas are helping to improve the understanding of the biology and the molecular mechanisms that underly its clinical behavior. The most recent WHO-HAEM5 classification of hematolymphoid tumors introduced novel molecular and histopathological findings that will aid in the diagnostic classification of this group of neoplasms. The current review article summarizes the most relevant diagnostic features of peripheral T-cell lymphomas with an emphasis on the updates that are incorporated at the WHO-HAEM5.

Genomic profiling for clinical decision making in lymphoid neoplasms

With the introduction of large-scale molecular profiling methods and high-throughput sequencing technologies, the genomic features of most lymphoid neoplasms have been characterized at an unprecedented scale. Although the principles for the classification and diagnosis of these disorders, founded on a multidimensional definition of disease entities, have been consolidated over the past 25 years, novel genomic data have markedly enhanced our understanding of lymphomagenesis and enriched the description of disease entities at the molecular level. Yet, the current diagnosis of lymphoid tumors is largely based on morphological assessment and immunophenotyping, with only few entities being defined by genomic criteria. This paper, which accompanies the International Consensus Classification of mature lymphoid neoplasms, will address how established assays and newly developed technologies for molecular testing already complement clinical diagnoses and provide a novel lens on disease classification. More specifically, their contributions to diagnosis refinement, risk stratification, and therapy prediction will be considered for the main categories of lymphoid neoplasms. The potential of whole-genome sequencing, circulating tumor DNA analyses, single-cell analyses, and epigenetic profiling will be discussed because these will likely become important future tools for implementing precision medicine approaches in clinical decision making for patients with lymphoid malignancies.

Targeting Chromatin-Remodeling Factors in Cancer Cells: Promising Molecules in Cancer Therapy

ATP-dependent chromatin-remodeling complexes can reorganize and remodel chromatin and thereby act as important regulator in various cellular processes. Based on considerable studies over the past two decades, it has been confirmed that the abnormal function of chromatin remodeling plays a pivotal role in genome reprogramming for oncogenesis in cancer development and/or resistance to cancer therapy. Recently, exciting progress has been made in the identification of genetic alteration in the genes encoding the chromatin-remodeling complexes associated with tumorigenesis, as well as in our understanding of chromatin-remodeling mechanisms in cancer biology. Here, we present preclinical evidence explaining the signaling mechanisms involving the chromatin-remodeling misregulation-induced cancer cellular processes, including DNA damage signaling, metastasis, angiogenesis, immune signaling, etc. However, even though the cumulative evidence in this field provides promising emerging molecules for therapeutic explorations in cancer, more research is needed to assess the clinical roles of these genetic cancer targets.

Nodal cytotoxic peripheral T-cell lymphoma occurs frequently in the clinical setting of immunodysregulation and is associated with recurrent epigenetic alterations

Nodal peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) with cytotoxic phenotype is overall rare, with most reports coming from Asia. Given its elusive pathobiology, we undertook a clinicopathological and molecular study of 54 Western patients diagnosed with PTCL, NOS expressing cytotoxic molecules, within a lymph node. More commonly males (M/F-2,6/1) with median age of 60 years were affected. Besides lymphadenopathy, 87% of patients had ≥1 involved extranodal site. High-stage disease (III-IV), International Prognostic Index >2, B symptoms, LDH level, and cytopenia(s) were observed in 92, 63, 67, 78, and 66% of cases, respectively. Ten patients had a history of B-cell malignancies, one each of myeloid neoplasm, breast or prostate cancer, and 4 others had underlying immune disorders. Most patients (70%) died, mostly of disease, with a median overall survival of 12.7 months. Immunophenotypically, the neoplastic lymphocytes were T-cell receptor (TCR) αβ + (47%), TCR-silent (44%) or TCRγδ+ (10%), commonly CD8 + (45%) or CD4-CD8- (32%). All except one had an activated cytotoxic profile, and 95% were subclassified into PTCL-TBX21 subtype based on CXCR3, TBX21, and GATA3 expression pattern. Seven patients (13%) disclosed EBER + tumor cells. Targeted DNA deep-sequencing (33 cases) and multiplex ligation-dependent reverse transcription-polymerase chain reaction assay (43 cases) identified frequent mutations in epigenetic modifiers (73%), including TET2 (61%) and DNMT3A (39%), recurrent alterations affecting the TCR (36%) and JAK/STAT (24%) signaling pathways and TP53 mutations (18%). Fusion transcripts involving VAV1 were identified in 6/43 patients (14%). Patients with nodal cytotoxic PTCL, NOS have an aggressive behavior and frequently present in a background of impaired immunity, although the association with Epstein-Barr virus is rare. The recurrent alterations in genes involved in DNA methylation together with genes related to cytokine or TCR signaling, suggest that co-operation of epigenetic modulation with cell-signaling pathways plays a critical role in the pathogeny of these lymphomas.

PD-1/PD-L1 Pathway: A Therapeutic Target in CD30+ Large Cell Lymphomas

The programmed death-ligands, PD-L1 and PD-L2, reside on tumor cells and can bind with programmed death-1 protein (PD-1) on T-cells, resulting in tumor immune escape. PD-1 ligands are highly expressed in some CD30+ large cell lymphomas, including classic Hodgkin lymphoma (CHL), primary mediastinal large B-cell lymphoma (PMBL), Epstein–Barr virus (EBV)-positive diffuse large B-cell lymphoma (EBV+ DLBCL), and anaplastic large cell lymphoma (ALCL). The genetic alteration of the chromosome 9p24.1 locus, the location of PD-L1, PD-L2, and JAK2 are the main mechanisms leading to PD-L1 and PD-L2 overexpression and are frequently observed in these CD30+ large cell lymphomas. The JAK/STAT pathway is also commonly constitutively activated in these lymphomas, further contributing to the upregulated expression of PD-L1 and PD-L2. Other mechanisms underlying the overexpression of PD-L1 and PD-L2 in some cases include EBV infection and the activation of the mitogen-activated protein kinase (MAPK) pathway. These cellular and molecular mechanisms provide a scientific rationale for PD-1/PD-L1 blockade in treating patients with relapsed/refractory (R/R) disease and, possibly, in newly diagnosed patients. Given the high efficacy of PD-1 inhibitors in patients with R/R CHL and PMBL, these agents have become a standard treatment in these patient subgroups. Preliminary studies of PD-1 inhibitors in patients with R/R EBV+ DLBCL and R/R ALCL have also shown promising results. Future directions for these patients will likely include PD-1/PD-L1 blockade in combination with other therapeutic agents, such as brentuximab or traditional chemotherapy regimens.

The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5^th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4^th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5^th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

Anaplastic Large Cell Lymphoma: Molecular Pathogenesis and Treatment

Simple Summary

Anaplastic large cell lymphoma is a rare type of disease that occurs throughout the world and has four subtypes. A summary and comparison of these subtypes can assist with advancing our knowledge of the mechanism and treatment of ALCL, which is helpful in making progress in this field.

Abstract

Anaplastic large cell lymphoma (ALCL) is an uncommon type of non-Hodgkin’s lymphoma (NHL), as well as one of the subtypes of T cell lymphoma, accounting for 1 to 3% of non-Hodgkin’s lymphomas and around 15% of T cell lymphomas. In 2016, the World Health Organization (WHO) classified anaplastic large cell lymphoma into four categories: ALK-positive ALCL (ALK+ALCL), ALK-negative ALCL (ALK−ALCL), primary cutaneous ALCL (pcALCL), and breast-implant-associated ALCL (BIA-ALCL), respectively. Clinical symptoms, gene changes, prognoses, and therapy differ among the four types. Large lymphoid cells with copious cytoplasm and pleomorphic characteristics with horseshoe-shaped or reniform nuclei, for example, are found in both ALK+ and ALK−ALCL. However, their epidemiology and pathogenetic origins are distinct. BIA-ALCL is currently recognized as a new provisional entity, which is a noninvasive disease with favorable results. In this review, we focus on molecular pathogenesis and management of anaplastic large cell lymphoma.

Genetic profiling and biomarkers in peripheral T-cell lymphomas: current role in the diagnostic work-up

Peripheral T-cell lymphomas are a heterogeneous, and usually aggressive, group of mature T-cell neoplasms with overlapping clinical, morphologic and immunologic features. A large subset of these neoplasms remains unclassifiable with current diagnostic methods ("not otherwise specified"). Genetic profiling and other molecular tools have emerged as widely applied and transformative technologies for discerning the biology of lymphomas and other hematopoietic neoplasms. Although the application of these technologies to peripheral T-cell lymphomas has lagged behind B-cell lymphomas and other cancers, molecular profiling has provided novel prognostic and diagnostic markers as well as an opportunity to understand the biologic mechanisms involved in the pathogenesis of these neoplasms. Some biomarkers are more prevalent in specific T-cell lymphoma subsets and are being used currently in the diagnosis and/or risk stratification of patients with peripheral T-cell lymphomas. Other biomarkers, while promising, need to be validated in larger clinical studies. In this review, we present a summary of our current understanding of the molecular profiles of the major types of peripheral T-cell lymphoma. We particularly focus on the use of biomarkers, including those that can be detected by conventional immunohistochemical studies and those that contribute to the diagnosis, classification, or risk stratification of these neoplasms.

Oncogenetic landscape of lymphomagenesis in coeliac disease

OBJECTIVE

Enteropathy-associated T-cell lymphoma (EATL) is a rare but severe complication of coeliac disease (CeD), often preceded by low-grade clonal intraepithelial lymphoproliferation, referred to as type II refractory CeD (RCDII). Knowledge on underlying oncogenic mechanisms remains scarce. Here, we analysed and compared the mutational landscape of RCDII and EATL in order to identify genetic drivers of CeD-associated lymphomagenesis.

DESIGN

Pure populations of RCDII-cells derived from intestinal biopsies (n=9) or sorted from blood (n=2) were analysed by whole exome sequencing, comparative genomic hybridisation and RNA sequencing. Biopsies from RCDII (n=50), EATL (n=19), type I refractory CeD (n=7) and uncomplicated CeD (n=18) were analysed by targeted next-generation sequencing. Moreover, functional in vitro studies and drug testing were performed in RCDII-derived cell lines.

RESULTS

80% of RCDII and 90% of EATL displayed somatic gain-of-functions mutations in the JAK1-STAT3 pathway, including a remarkable p.G1097 hotspot mutation in the JAK1 kinase domain in approximately 50% of cases. Other recurrent somatic events were deleterious mutations in nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) regulators TNFAIP3 and TNIP3 and potentially oncogenic mutations in TET2, KMT2D and DDX3X. JAK1 inhibitors, and the proteasome inhibitor bortezomib could block survival and proliferation of malignant RCDII-cell lines.

CONCLUSION

Mutations activating the JAK1-STAT3 pathway appear to be the main drivers of CeD-associated lymphomagenesis. In concert with mutations in negative regulators of NF-κB, they may favour the clonal emergence of malignant lymphocytes in the cytokine-rich coeliac intestine. The identified mutations are attractive therapeutic targets to treat RCDII and block progression towards EATL.

Current Progress in Breast Implant-Associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is an uncommon type of T-cell lymphoma. Although with a low incidence, the epidemiological data raised the biosafety and health concerns of breast reconstruction and breast augmentation for BIA-ALCL. Emerging evidence confirms that genetic features, bacterial contamination, chronic inflammation, and textured breast implant are the relevant factors leading to the development of BIA-ALCL. Almost all reported cases with a medical history involve breast implants with a textured surface, which reflects the role of implant surface characteristics in BIA-ALCL. With this review, we expect to highlight the most significant features on etiology, pathogenesis, diagnosis, and therapy of BIA-ALCL, as well as we review the physical characteristics of breast implants and their potential pathogenic effect and hopefully provide a foundation for optimal choice of type of implant with minimal morbidity.

Genomic Analysis of Cutaneous CD30-Positive Lymphoproliferative Disorders

Primary cutaneous CD30⁺ T-cell lymphoproliferative disorders are the second most common cutaneous lymphomas. According to the World Health Organization, CD30⁺ T-cell lymphoproliferative disorders include primary cutaneous anaplastic large cell lymphoma (C-ALCL) and lymphomatoid papulosis (LyP) as well as borderline lesions. C-ALCL and LyP are thought to represent two ends of a spectrum of diseases that have different clinical presentations, clinical courses, and prognoses in their classic forms but share the same histology of medium to large CD30⁺ atypical lymphoid cell infiltrates. Because the behavior of these entities is different clinically and prognostically, we aim to search for oncogenic genomic variants using whole-exome sequencing that drive the development of LyP and C-ALCL. Clinical information, pathology, immunohistochemistry, and T-cell rearrangements on six cases of LyP and five cases of C-ALCL were reviewed to confirm the rendered diagnosis before whole-exome sequencing of all specimens. Both LyP and C-ALCL had recurrent alterations in epigenetic modifying genes affecting histone methylation and acetylation (SETD2, KMT2A, KMT2D, and CREBBP). However, they also harbor unique differences with mutations in signal transducer and activator of transcription gene STAT3 of the Jak/signal transducer and activator of transcription pathway and EOMES, a transcription factor involved in lymphocyte development, only noted in C-ALCL specimens. Genomic characterization of LyP and C-ALCL in this series confirms the role of multiple pathways involved in the biology and development of these lymphomatous processes. The identification of similar aberrations within the epigenetic modifying genes emphasizes common potential development mechanisms of lymphomagenesis within lymphoproliferative disorders being shared between LyP and C-ALCL; however, the presence of differences may account for the differences in clinical course.

RNA Sequencing of Primary Cutaneous and Breast-Implant Associated Anaplastic Large Cell Lymphomas Reveals Infrequent Fusion Transcripts and Upregulation of PI3K/AKT Signaling via Neurotrophin Pathway Genes

Simple Summary

Cutaneous and breast implant-associated anaplastic large-cell lymphomas are usually localized neoplasms with an indolent clinical course compared to systemic ALCL. However comparative analyses of the molecular features of these two entities have not yet been reported. We performed targeted RNA sequencing, which revealed that fusion transcripts, although infrequent, might represent additional pathogenetic events in both diseases. We also found that these entities display upregulation of the PI3K/Akt pathway and show enrichment in genes of the neurotrophin signaling pathway. These findings advance our knowledge regarding the pathobiology of cALCL and BI-ALCL and point to additional therapeutic targets.

Abstract

Cutaneous and breast implant-associated anaplastic large-cell lymphomas (cALCLs and BI-ALCLs) are two localized forms of peripheral T-cell lymphomas (PTCLs) that are recognized as distinct entities within the family of ALCL. JAK-STAT signaling is a common feature of all ALCL subtypes, whereas DUSP22/IRF4, TP63 and TYK gene rearrangements have been reported in a proportion of ALK-negative sALCLs and cALCLs. Both cALCLs and BI-ALCLs differ in their gene expression profiles compared to PTCLs; however, a direct comparison of the genomic alterations and transcriptomes of these two entities is lacking. By performing RNA sequencing of 1385 genes (TruSight RNA Pan-Cancer, Illumina) in 12 cALCLs, 10 BI-ALCLs and two anaplastic lymphoma kinase (ALK)-positive sALCLs, we identified the previously reported TYK2-NPM1 fusion in 1 cALCL (1/12, 8%), and four new intrachromosomal gene fusions in 2 BI-ALCLs (2/10, 20%) involving genes on chromosome 1 (EPS15-GNG12 and ARNT-GOLPH3L) and on chromosome 17 (MYO18A-GIT1 and NF1-GOSR1). One of the two BI-ALCL samples showed a complex karyotype, raising the possibility that genomic instability may be responsible for intra-chromosomal fusions in BI-ALCL. Moreover, transcriptional analysis revealed similar upregulation of the PI3K/Akt pathway, associated with enrichment in the expression of neurotrophin signaling genes, which was more conspicuous in BI-ALCL, as well as differences, i.e., over-expression of genes involved in the RNA polymerase II transcription program in BI-ALCL and of the RNA splicing/processing program in cALCL.

Janus Kinase Signaling: Oncogenic Criminal of Lymphoid Cancers

Simple Summary

Janus kinases (JAKs) are transmembrane receptors that pass signals from extracellular ligands to downstream. Increasing evidence has suggested that JAK family aberrations promote lymphoid cancer pathogenesis and progression through mediating gene expression via the JAK/STAT pathway or noncanonical JAK signaling. We are here to review how canonical JAK/STAT and noncanonical JAK signalings are represented and deregulated in lymphoid malignancies and how to target JAK for therapeutic purposes.

Abstract

The Janus kinase (JAK) family are known to respond to extracellular cytokine stimuli and to phosphorylate and activate signal transducers and activators of transcription (STAT), thereby modulating gene expression profiles. Recent studies have highlighted JAK abnormality in inducing over-activation of the JAK/STAT pathway, and that the cytoplasmic JAK tyrosine kinases may also have a nuclear role. A couple of anti-JAK therapeutics have been developed, which effectively harness lymphoid cancer cells. Here we discuss mutations and fusions leading to JAK deregulations, how upstream nodes drive JAK expression, how classical JAK/STAT pathways are represented in lymphoid malignancies and the noncanonical and nuclear role of JAKs. We also summarize JAK inhibition therapeutics applied alone or synergized with other drugs in treating lymphoid malignancies.

An Update on the Current Genomic Landscape of Breast Implant-Associated Anaplastic Large Cell Lymphoma

Simple Summary

Breast implant-associated lymphoma is a unique entity that arises in the setting of breast prostheses due to a complex interplay of external and internal factors. Understanding of the mechanisms of pathogenesis is yet to be fully elucidated but recurrent mutations in signalling pathways, tumour suppressors and epigenetic regulators have been reported. This article summarises the key studies to date that have described these genetic aberrancies, which have provided an insight into potential pathways to lymphogenesis.

Abstract

Breast implant-associated lymphoma (BIA-ALCL) is a rare subtype of anaplastic large-cell lymphoma associated with breast prostheses. Most patients present with a localised periprosthetic effusion and are managed with removal of the implant and surrounding capsule. Less commonly, the lymphoma can form a mass associated with the capsule and rarely can present with disseminated disease. Recent series characterising the genomic landscape of BIA-ALCL have led to insights into the mechanisms of lymphomagenesis. Constitutive JAK/STAT pathway activation has emerged as a likely key component while, more recently, aberrancies in epigenetic regulators have been reported. This review describes the genomic characterisation reported to date and the insight these findings have provided into this rare entity.

ALK-Negative Anaplastic Large Cell Lymphoma: Current Concepts and Molecular Pathogenesis of a Heterogeneous Group of Large T-Cell Lymphomas

Simple Summary

ALK- anaplastic large cell lymphoma (ALK- ALCL) is a rare subtype of CD30+ large T-cell lymphoma that typically affects older adults and has a poor prognosis. Recognition of its histopathologic spectrum, subtypes, and of other tumors that can resemble ALK- ALCL is crucial to avoid making a wrong diagnosis that could result in inappropriate treatment for a patient. In recent years, several important studies have identified recurrent molecular alterations that have shed light on the pathogenesis of this lymphoma. However, on the other hand, putting all this vast information together into a concise form has become challenging. In this review, we present not only a more detailed view of the histopathologic findings of ALK- ALCL but also, we attempt to provide a more simplified perspective of the relevant genetic and molecular alterations of this type of lymphoma, that in our opinion, is not available to date.

Abstract

Anaplastic large cell lymphoma (ALCL) is a subtype of CD30+ large T-cell lymphoma (TCL) that comprises ~2% of all adult non-Hodgkin lymphomas. Based on the presence/absence of the rearrangement and expression of anaplastic lymphoma kinase (ALK), ALCL is divided into ALK+ and ALK-, and both differ clinically and prognostically. This review focuses on the historical points, clinical features, histopathology, differential diagnosis, and relevant cytogenetic and molecular alterations of ALK- ALCL and its subtypes: systemic, primary cutaneous (pc-ALCL), and breast implant-associated (BIA-ALCL). Recent studies have identified recurrent genetic alterations in this TCL. In systemic ALK- ALCL, rearrangements in DUSP22 and TP63 are detected in 30% and 8% of cases, respectively, while the remaining cases are negative for these rearrangements. A similar distribution of these rearrangements is seen in pc-ALCL, whereas none have been detected in BIA-ALCL. Additionally, systemic ALK- ALCL—apart from DUSP22-rearranged cases—harbors JAK1 and/or STAT3 mutations that result in the activation of the JAK/STAT signaling pathway. The JAK1/3 and STAT3 mutations have also been identified in BIA-ALCL but not in pc-ALCL. Although the pathogenesis of these alterations is not fully understood, most of them have prognostic value and open the door to the use of potential targeted therapies for this subtype of TCL.

Towards Understanding the Pathogenicity of DROSHA Mutations in Oncohematology

Myelodysplastic syndrome (MDS) refers to a heterogeneous group of closely related clonal hematopoietic disorders, which are characterized by accumulation of somatic mutations. The acquired mutation burden is suggested to define the pathway and consequent phenotype of the pathology. Recent studies have called attention to the role of miRNA biogenesis genes in MDS progression; in particular, the mutational pressure of the DROSHA gene was determined. Therefore, this highlights the importance of studying the impact of all collected missense mutations found within the DROSHA gene in oncohematology that might affect the functionality of the protein. In this study, the selected mutations were extensively examined by computational screening, and the most deleterious were subjected to a further molecular dynamic simulation in order to uncover the molecular mechanism of the structural damage to the protein altering its biological function. The most significant effect was found for variants I625K, L1047S, and H1170D, presumably affecting the endonuclease activity of DROSHA. Such alterations arisen during MDS progression should be taken into consideration as evoking certain clinical traits in the malignifying clonal evolution.

Cytokines, Genetic Lesions and Signaling Pathways in Anaplastic Large Cell Lymphomas

ALCL is a tumor of activated T cells and possibly innate lymphoid cells with several subtypes according to clinical presentation and genetic lesions. On one hand, the expression of transcription factors and cytokine receptors triggers signaling pathways. On the other hand, ALCL tumor cells also produce many proteins including chemokines, cytokines and growth factors that affect patient symptoms. Examples are accumulation of granulocytes stimulated by IL-8, IL-17, IL-9 and IL-13; epidermal hyperplasia and psoriasis-like skin lesions due to IL-22; and fever and weight loss in response to IL-6 and IFN-γ. In this review, we focus on the biology of the main ALCL subtypes as the identification of signaling pathways and ALCL-derived cytokines offers opportunities for targeted therapies.

Current Progress in Investigating Mature T- and NK-Cell Lymphoma Gene Aberrations by Next-Generation Sequencing (NGS)

Despite efforts to abrogate the severe threat to life posed by the profound malignancy of mature natural killer/T-cell lymphoma (NKTCL), therapeutic advances still require further investigation of its inherent regulatory biochemical processes. Next-generation sequencing (NGS) is an increasingly developing gene detection technique, which has been widely used in lymphoma genetic research in recent years. Targeted therapy based on the above studies has also generated a series of advances, making genetic mutation a new research hotspot in lymphoma. Advances in NKTCL-related gene mutations are reviewed in this paper.

Molecular profiling reveals a hypoxia signature in breast implant-associated anaplastic large cell lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIAALCL) is a recently characterized T-cell malignancy that has raised significant patient safety concerns and led to worldwide impact on the implants used and clinical management of patients undergoing reconstructive or cosmetic breast surgery. Molecular signatures distinguishing BIA-ALCL from other anaplastic large cell lymphomas have not been fully elucidated and classification of BIA-ALCL as a World Health Organization entity remains provisional. We performed RNA sequencing and gene set enrichment analysis comparing BIA-ALCL to non-BIAALCL and identified dramatic upregulation of hypoxia signaling genes including the hypoxia-associated biomarker CA9 (carbonic anyhydrase- 9). Immunohistochemistry validated CA9 expression in all BIA-ALCL, with only minimal expression in non-BIA-ALCL. Growth induction in BIA-ALCL-derived cell lines cultured under hypoxic conditions was proportional to upregulation of CA9 expression, and RNA sequencing demonstrated induction of the same gene signature observed in BIAALCL tissue samples compared to non-BIA-ALCL. CA9 silencing blocked hypoxia-induced BIA-ALCL cell growth and cell cycle-associated gene expression, whereas CA9 overexpression in BIA-ALCL cells promoted growth in a xenograft mouse model. Furthermore, CA9 was secreted into BIA-ALCL cell line supernatants and was markedly elevated in human BIA-ALCL seroma samples. Finally, serum CA9 concentrations in mice bearing BIA-ALCL xenografts were significantly elevated compared to those in control serum. Together, these findings characterize BIA-ALCL as a hypoxia-associated neoplasm, likely attributable to the unique microenvironment in which it arises. These data support classification of BIA-ALCL as a distinct entity and uncover opportunities for investigating hypoxia-related proteins such as CA9 as novel biomarkers and therapeutic targets in this disease.

Overexpression of ING3 is associated with attenuation of migration and invasion in breast cancer

Inhibitor of growth 3 (ING3) has been identified as a potential cancer drug target, but little is known about its role in breast cancer. Thus, the present study aimed to investigate ING3 expression in breast cancer, its clinical value, and how ING3 influences the migration and invasion of breast cancer cells. The Cancer Genome Atlas and UALCAN databases were used to analyze ING3 expression in cancer tissues and normal tissues. Survival analysis was performed using the UALCAN, UCSC Xena and KM-plot databases. In addition, reverse transcription-quantitative PCR and western blot analyses were performed to detect ING3 mRNA and protein expression levels. ING3 was overexpressed via lentiviral vector transfection, while the Transwell and wound healing assays were performed to assess the cell migratory and invasive abilities. Protein interaction and pathway analyses were performed using the GeneMANIA and Kyoto Encyclopedia of Genes and Genomes databases, respectively. The results demonstrated that ING3 expression was significantly lower in cancer tissues compared with normal tissues (P<0.05). In addition, luminal A and human epidermal growth factor receptor 2 (HER2)-enriched breast cancer tissues expressed lower levels of ING3 compared with normal breast tissues. Notably, statistically significant differences were observed in long-term survival between patients with luminal A (P=0.04) and HER2-enriched (P=0.008) breast cancer, with high and low expression levels of ING3. The results of the Transwell migration and invasion assays demonstrated that overexpression of ING3 significantly inhibited the migratory and invasive abilities of MCF7 (P<0.05) and HCC1937 (P<0.05) cells. The results of the wound healing assay demonstrated that the percentage wound closure significantly decreased in cells transfected with LV5-ING3 compared with the negative control group at 12 h (P<0.05) and 24 h (P<0.01). The PI3K/AKT, JAK/STAT, NF-κB and Wnt/β-catenin pathways are the potential pathways regulated by ING3. Notably, overexpression of ING3 inhibited migration and invasion in vitro. However, further studies are required to determine whether ING3 regulates the biological behavior of breast cancer via tumor-related pathways.

Alternative splicing redefines landscape of commonly mutated genes in acute myeloid leukemia

Most genes associated with acute myeloid leukemia (AML) are mutated in less than 10% of patients, suggesting that alternative mechanisms of gene disruption contribute to this disease. Here, we find a set of splicing events that alter the expression of a subset of AML-associated genes independent of known somatic mutations. In particular, aberrant splicing triples the number of patients with reduced functional EZH2 compared with that predicted by somatic mutation alone. In addition, we unexpectedly find that the nonsense-mediated decay factor DHX34 exhibits widespread alternative splicing in sporadic AML, resulting in a premature stop codon that phenocopies the loss-of-function germline mutations observed in familial AML. Together, these results demonstrate that classical mutation analysis underestimates the burden of functional gene disruption in AML and highlight the importance of assessing the contribution of alternative splicing to gene dysregulation in human disease.

Mucosal Epithelial Jak Kinases in Health and Diseases

Janus kinases (Jaks) are a family of nonreceptor tyrosine kinase that include four different members, viz., Jak1, Jak2, Jak3, and Tyk2. Jaks play critical roles in immune cells functions; however, recent studies suggest they also play essential roles in nonimmune cell physiology. This review highlights the significance of epithelial Jaks in understanding the molecular basis of some of the diseases through regulation of epithelial-mesenchymal transition, cell survival, cell growth, development, and differentiation. Growth factors and cytokines produced by the cells of hematopoietic origin use Jak kinases for signal transduction in both immune and nonimmune cells. Among Jaks, Jak3 is widely expressed in both immune cells and in intestinal epithelial cells (IECs) of both humans and mice. Mutations that abrogate Jak3 functions cause an autosomal severe combined immunodeficiency disease (SCID) while activating Jak3 mutations lead to the development of hematologic and epithelial cancers. A selective Jak3 inhibitor CP-690550 (Xeljanz) approved by the FDA for certain chronic inflammatory conditions demonstrates immunosuppressive activity in rheumatoid arthritis, psoriasis, and organ transplant rejection. Here, we also focus on the consequences of Jak3-directed drugs on adverse effects in light of recent discoveries in mucosal epithelial functions of Jak3 with some information on other Jaks. Lastly, we brief on structural implications of Jak3 domains beyond the immune cells. As information about the roles of Jak3 in gastrointestinal functions and associated diseases are only just emerging, in the review, we summarize its implications in gastrointestinal wound repair, inflammatory bowel disease, obesity-associated metabolic syndrome, and epithelial cancers. Lastly, we shed lights on identifying potential novel targets in developing therapeutic interventions of diseases associated with dysfunctional IEC.

Requirement of DNMT1 to orchestrate epigenomic reprogramming for NPM-ALK-driven lymphomagenesis

Malignant transformation depends on genetic and epigenetic events that result in a burst of deregulated gene expression and chromatin changes. To dissect the sequence of events in this process, we used a T-cell-specific lymphoma model based on the human oncogenic nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) translocation. We find that transformation of T cells shifts thymic cell populations to an undifferentiated immunophenotype, which occurs only after a period of latency, accompanied by induction of the MYC-NOTCH1 axis and deregulation of key epigenetic enzymes. We discover aberrant DNA methylation patterns, overlapping with regulatory regions, plus a high degree of epigenetic heterogeneity between individual tumors. In addition, ALK-positive tumors show a loss of associated methylation patterns of neighboring CpG sites. Notably, deletion of the maintenance DNA methyltransferase DNMT1 completely abrogates lymphomagenesis in this model, despite oncogenic signaling through NPM-ALK, suggesting that faithful maintenance of tumor-specific methylation through DNMT1 is essential for sustained proliferation and tumorigenesis.

UK Guidelines on the Diagnosis and Treatment of Breast Implant-Associated Anaplastic Large Cell Lymphoma on behalf of the Medicines and Healthcare products Regulatory Agency Plastic, Reconstructive and Aesthetic Surgery Expert Advisory Group

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon T-cell non-Hodgkin Lymphoma (NHL) associated with breast implants. Raising awareness of the possibility of BIA-ALCL in anyone with breast implants and new breast symptoms is crucial to early diagnosis. The tumour begins on the inner aspect of the peri-implant capsule causing an effusion, or less commonly a tissue mass to form within the capsule, which may spread locally or to more distant sites in the body. Diagnosis is usually made by cytological, immunohistochemical and immunophenotypic evaluation of the aspirated peri-implant fluid: pleomorphic lymphocytes are characteristically anaplastic lymphoma kinase (ALK)-negative and strongly positive for CD30. BIA-ALCL is indolent in most patients but can progress rapidly. Surgical removal of the implant with the intact surrounding capsule (total en-bloc capsulectomy) is usually curative. Late diagnosis may require more radical surgery and systemic therapies and although these are usually successful, poor outcomes and deaths have been reported. By adopting a structured approach, as suggested in these guidelines, early diagnosis and successful treatment will minimise the need for systemic treatments, reduce morbidity and the risk of poor outcomes.

The DNA-helicase HELLS drives ALK- ALCL proliferation by the transcriptional control of a cytokinesis-related program

Deregulation of chromatin modifiers, including DNA helicases, is emerging as one of the mechanisms underlying the transformation of anaplastic lymphoma kinase negative (ALK^-) anaplastic large cell lymphoma (ALCL). We recently identified the DNA-helicase HELLS as central for proficient ALK^-ALCL proliferation and progression. Here we assessed in detail its function by performing RNA-sequencing profiling coupled with bioinformatic prediction to identify HELLS targets and transcriptional cooperators. We demonstrated that HELLS, together with the transcription factor YY1, contributes to an appropriate cytokinesis via the transcriptional regulation of genes involved in cleavage furrow regulation. Binding target promoters, HELLS primes YY1 recruitment and transcriptional activation of cytoskeleton genes including the small GTPases RhoA and RhoU and their effector kinase Pak2. Single or multiple knockdowns of these genes reveal that RhoA and RhoU mediate HELLS effects on cell proliferation and cell division of ALK^-ALCLs. Collectively, our work demonstrates the transcriptional role of HELLS in orchestrating a complex transcriptional program sustaining neoplastic features of ALK^-ALCL.

CHD2-Related CNS Pathologies

Epileptic encephalopathies (EE) are severe epilepsy syndromes characterized by multiple seizure types, developmental delay and even regression. This class of disorders are increasingly being identified as resulting from de novo genetic mutations including many identified mutations in the family of chromodomain helicase DNA binding (CHD) proteins. In particular, several de novo pathogenic mutations have been identified in the gene encoding chromodomain helicase DNA binding protein 2 (CHD2), a member of the sucrose nonfermenting (SNF-2) protein family of epigenetic regulators. These mutations in the CHD2 gene are causative of early onset epileptic encephalopathy, abnormal brain function, and intellectual disability. Our understanding of the mechanisms by which modification or loss of CHD2 cause this condition remains poorly understood. Here, we review what is known and still to be elucidated as regards the structure and function of CHD2 and how its dysregulation leads to a highly variable range of phenotypic presentations.

Etiology of Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL): Current Directions in Research

Simple Summary

The first report of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) was in 1997. Although BIA-ALCL develops around breast implants, it is considered a cancer of the immune system and not a cancer of the breast ducts or lobules. Nearly all confirmed cases to date have been associated with textured surface (versus smooth surface) breast implants. As physicians have become more aware of BIA-ALCL, so has the number of reported cases, although the number of cases remains low. In most instances, patients have an excellent prognosis following removal of the breast implant and its surrounding fibrous capsule. Many theories on factors that trigger the development of BIA-ALCL, such as the presence of bacteria, have been proposed. However, the sequence(s) of events that follow the initial triggering event(s) have not been fully determined. This article summarizes the current scientific knowledge on the development of BIA-ALCL.

Abstract

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a CD30-positive, anaplastic lymphoma kinase-negative T-cell lymphoma. Where implant history is known, all confirmed cases to date have occurred in patients with exposure to textured implants. There is a spectrum of disease presentation, with the most common occurring as a seroma with an indolent course. A less common presentation occurs as locally advanced or, rarely, as metastatic disease. Here we review the immunological characteristics of BIA-ALCL and potential triggers leading to its development. BIA-ALCL occurs in an inflammatory microenvironment with significant lymphocyte and plasma cell infiltration and a prominent Th1/Th17 phenotype in advanced disease. Genetic lesions affecting the JAK/STAT signaling pathway are commonly present. Proposed triggers for the development of malignancy include mechanical friction, silicone implant shell particulates, silicone leachables, and bacteria. Of these, the bacterial hypothesis has received significant attention, supported by a plausible biologic model. In this model, bacteria form an adherent biofilm in the favorable environment of the textured implant surface, producing a bacterial load that elicits a chronic inflammatory response. Bacterial antigens, primarily of Gram-negative origin, may trigger innate immunity and induce T-cell proliferation with subsequent malignant transformation in genetically susceptible individuals. Although much remains to be elucidated regarding the multifactorial origins of BIA-ALCL, future research should focus on prevention and treatment strategies, recognizing susceptible populations, and whether decreasing the risk of BIA-ALCL is possible.

Mutation Spectra of the MRN (MRE11, RAD50, NBS1/NBN) Break Sensor in Cancer Cells

Simple Summary

A DNA double strand break cuts a chromosome in two and is one of the most dangerous forms of DNA damage. Improper repair can lead to various chromosomal re-arrangements that have been detected in almost all cancer cells. A complex of three proteins (MRE11, RAD50, NBS1 or NBN) detects chromosome breaks and orchestrates repair processes. Mutations in these “break sensor” genes have been described in a multitude of cancers. Here, we provide a comprehensive analysis of reported mutations from data deposited on the Catalogue of Somatic Mutations in Cancer (COSMIC) archive. We also undertake an evolutionary analysis of these genes with the aim to understand whether these mutations preferentially accumulate in conserved residues. Interestingly, we find that mutations are overrepresented in evolutionarily conserved residues of RAD50 and NBS1/NBN but not MRE11.

Abstract

The MRN complex (MRE11, RAD50, NBS1/NBN) is a DNA double strand break sensor in eukaryotes. The complex directly participates in, or coordinates, several activities at the break such as DNA resection, activation of the DNA damage checkpoint, chromatin remodeling and recruitment of the repair machinery. Mutations in components of the MRN complex have been described in cancer cells for several decades. Using the Catalogue of Somatic Mutations in Cancer (COSMIC) database, we characterized all the reported MRN mutations. This analysis revealed several hotspot frameshift mutations in all three genes that introduce premature stop codons and truncate large regions of the C-termini. We also found through evolutionary analyses that COSMIC mutations are enriched in conserved residues of NBS1/NBN and RAD50 but not in MRE11. Given that all three genes are important to carcinogenesis, we propose these differential enrichment patterns may reflect a more severe pleiotropic role for MRE11.

A Novel JAK1 Mutant Breast Implant-Associated Anaplastic Large Cell Lymphoma Patient-Derived Xenograft Fostering Pre-Clinical Discoveries

Breast implant-associated lymphoma (BIA-ALCL) has recently been recognized as an independent peripheral T-cell lymphoma (PTCL) entity. In this study, we generated the first BIA-ALCL patient-derived tumor xenograft (PDTX) model (IL89) and a matching continuous cell line (IL89_CL#3488) to discover potential vulnerabilities and druggable targets. We characterized IL89 and IL89_CL#3488, both phenotypically and genotypically, and demonstrated that they closely resemble the matching human primary lymphoma. The tumor content underwent significant enrichment along passages, as confirmed by the increased variant allele frequency (VAF) of mutations. Known aberrations (JAK1 and KMT2C) were identified, together with novel hits, including PDGFB, PDGFRA, and SETBP1. A deep sequencing approach allowed the detection of mutations below the Whole Exome Sequencing (WES) sensitivity threshold, including JAK1G1097D, in the primary sample. RNA sequencing confirmed the expression of a signature of differentially expressed genes in BIA-ALCL. Next, we tested IL89’s sensitivity to the JAK inhibitor ruxolitinib and observed a potent anti-tumor effect, both in vitro and in vivo. We also implemented a high-throughput drug screening approach to identify compounds associated with increased responses in the presence of ruxolitinib. In conclusion, these new IL89 BIA-ALCL models closely recapitulate the primary correspondent lymphoma and represent an informative platform for dissecting the molecular features of BIA-ALCL and performing pre-clinical drug discovery studies, fostering the development of new precision medicine approaches.

Breast implant-associated anaplastic large cell lymphoma: A comprehensive review

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a recently recognized non-Hodgkin lymphoma of T-cell origin. Despite the low incidence of this new disease, the increasing use of breast implants for cosmetic or post-mastectomy reconstruction purposes places BIA-ALC as an emerging and compelling medical challenge. The real BIA-ALCL pathogenesis has not been fully uncovered so far, while different putative causal factors have been proposed. Breast implants with textured surfaces seem to be associated with nearly all cases of BIA-ALCL, while the real the risk of disease development has not been well estimated so far. Late onset, persistent seroma around breast implant represents the classical clinical presentation. Most of the BIA-ALCL patients presents with localized disease, which confers an excellent prognosis. Unlike other non-Hodgkin lymphomas, surgical excision of the mass has a key role in the treatment. For patients with advanced and disseminated diseases, the treatment did not differ from other types of T-cell lymphoma. For these reasons, BIA-ALCL represents an emerging disease which requires multidisciplinary team approach to well define diagnostic workup and treatment for each patient. This review article aims to summarize available data on BIA-ALCL. First, we will outline available data on BIA-ALCL epidemiology, pathogenesis, diagnostic work-up, and treatment. Second, we will point out the potential psychological implications as well as the risk of perception distortion for women with breast implants, especially for those with previous breast cancer. Lastly, we will summarize the current national recommendations regarding textured breast implants and discuss the diagnostic-therapeutic algorithm for BIA-ALCL management.