Recurrent genomic rearrangements in primary testicular lymphoma

Primary testicular lymphoma demonstrates overexpression of the Wilms tumor 1 gene and different mRNA and miRNA expression profiles compared to nodal diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) shows a high degree of clinical and biological heterogeneity. Primary testicular lymphoma (PTL) is an extranodal variant of DLBCL associated with a higher risk of recurrence, including contralateral testicles and central nervous system sanctuary sites. Several molecular aberrations, including somatic mutation of MYD88, CD79B, and upregulation of NF-kB, PDL-1, and PDL-2, are thought to contribute to the pathogenesis and poor prognosis of PTL. However, additional biomarkers are needed that may improve the prognosis and help understand the PTL biology and lead to new therapeutic targets. RNA from diagnostic tissue biopsies of the PTL-ABC subtype and matched nodal DLBCL-ABC subtype patients was evaluated by mRNA and miRNA expression. Screening of 730 essential oncogenic genes was performed, and their epigenetic connections were examined using the nCounter PAN-cancer pathway, and Human miRNA assays with the nCounter System (NanoString Technologies). PTL and nodal DLBCL patients were comparable in age, gender, and putative cell of origin (p > 0.05). Wilms tumor 1 (WT1) expression in PTL exceeded that in nodal DLBCL (>6-fold; p = 0.01, FDR <0.01) and WT1 associated pathway genes THBS4, PTPN5, PLA2G2A, and IFNA17 were upregulated in PTL (>2.0-fold, p < 0.01, FDR <0.01). Additionally, miRNAs targeting WT1 (hsa15a-5p, hsa-miR-16-5p, has-miR-361-5p, has-miR-27b-3p, has-miR-199a-5p, has-miR-199b-5p, has-miR-132-3p, and hsa-miR-128-3p) showed higher expression in PTL compared to nodal DLBCL (≥2.0-fold; FDR 0.01). Lower expression of BMP7, LAMB3, GAS1, MMP7, and LAMC2 (>2.0-fold, p < 0.01) was observed in PTL compared to nodal DLBCL. This research revealed higher WT1 expression in PTL relative to nodal DLBCL, suggesting that a specific miRNA subset may target WT1 expression and impact the PI3k/Akt pathway in PTL. Further investigation is needed to explore WT1's biological role in PTL and its potential as a therapeutic target.

Detection distribution of CNVs of SNX29 in three goat breeds and their associations with growth traits

As a member of the SNX family, the goat sorting nexin 29 (SNX29) is initially identified as a myogenesis gene. Therefore, this study aimed to examine the polymorphism in the SNX29 gene and its association with growth traits. In this study, we used an online platform to predict the structures of the SNX29 protein and used quantitative real-time PCR to detect potential copy number variation (CNV) in Shaanbei white cashmere (SBWC) goats (n = 541), Guizhou black (GB) goats (n = 48), and Nubian (NB) goats (n = 39). The results showed that goat SNX29 protein belonged to non-secretory protein. Then, five CNVs were detected, and their association with growth traits was analyzed. In SBWC goats, CNV1, CNV3, CNV4, and CNV5 were associated with chest width and body length (P < 0.05). Among them, the CNV1 individuals with gain and loss genotypes were superior to those individuals with a median genotype, but CNV4 and CNV5 of individuals with the median genotype were superior to those with the loss and gain genotypes. In addition, individuals with the gain genotype had superior growth traits in CNV3. In brief, this study suggests that the CNV of SNX29 can be used as a molecular marker in goat breeding.

A novel SMARCA2-CREM fusion expending the molecular spectrum of salivary gland hyalinazing clear cell carcinoma beyond the FET genes

Hyalinizing clear cell carcinoma (HCCC) is a rare salivary gland carcinoma with a generally indolent behavior, characterized by recurrent chromosomal translocation involving EWSR1 (22q12.2) leading to two fusion genes EWSR1::ATF1 or EWSR1::CREM. We report one case of HCCC with a novel SMARCA2::CREM fusion, identified by targeted RNA next generation sequencing by LD-RT-PCR, which has until now never been described in salivary glands. The exon 4 of SMARCA2 is fused to exon 5 of CREM. This fusion has been described previously in only one tumor, a central nervous system tumor (intracranial mesenchymal tumor) but not in other FET::CREB fused tumors. This fusion was confirmed by CREM break-apart FISH and reverse transcriptase polymerase chain reaction (RT-PCR). The tumor cells showed retained expression of INI1, SMARCA2, and SMARCA4 by immunohistochemistry. We compare its clinical, histopathological, immunophenotypic, genetic features with those previously described in HCCC, FET::CREB fusion-positive. Our results added data suggesting that different histomolecular tumor subtypes seem to be included within the terminology "HCCC, FET::CREB fusion-positive," and that further series of cases are needed to better characterize them.

A Novel Approach: Combining Prognostic Models and Network Pharmacology to Target Breast Cancer Necroptosis-Associated Genes

Breast cancer (BC) accounts for the highest proportion of the all cancers among women, and necroptosis is recognized as a form of caspase-independent programmed cell death. We created prognostic signatures using univariate survival analysis, and lasso regression, to assess immune microenvironments between subgroups. We then used network pharmacology to bind our drugs to target differentially expressed genes (DEGs). A signature comprising a set of necroptosis-related genes was established to predict patient outcomes based on median risk scores. Those above and below the median were classified as high-risk group (HRG) and low-risk group (LRG), respectively. Patients at high risk had lower overall survival, and poorer predicted tumor, nodes, and metastases stages (TNM). The novel prognostic signature can effectively predict the prognosis of breast cancer patients docking of β,β-dimethyl acryloyl shikonin (DMAS) to possible targets to cure breast cancer. We found that all current prognostic models do not offer suitable treatment options. In additional, by docking drugs DMAS that have been initially validated in our laboratory to treat breast cancer. We hope that this novel approach could contribute to cancer research.

Testicular Diffuse Large B-Cell Lymphoma-Clinical, Molecular, and Immunological Features

Simple Summary

Testicular diffuse large B-cell lymphoma (T-DLBCL) is a rare and aggressive lymphoma entity that mainly affects elderly men. It has a high relapse rate with especially the relapses of the central nervous system associating with dismal outcome. T-DLBCL has a unique biology with distinct genetic characteristics and clinical presentation, and the increasing knowledge on the tumor microenvironment of T-DLBCL highlights the significance of the host immunity and immune escape in this rare lymphoma, presenting in an immune-privileged site of the testis. This review provides an update on the latest progress made in T-DLBCL research and summarizes the clinical perspectives in T-DLBCL.

Abstract

Primary testicular lymphoma is a rare lymphoma entity, yet it is the most common testicular malignancy among elderly men. The majority of the cases represent non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL) with aggressive clinical behavior and a relatively high relapse rate. Due to the rareness of the disease, no randomized clinical trials have been conducted and the currently recognized standard of care is based on retrospective analyses and few phase II trials. During recent years, the tumor microenvironment (TME) and tumor-related immunity have been the focus of many tumor biology studies, and the emergence of targeted therapies and checkpoint inhibitors has significantly modulated the field of cancer therapies. Testicular DLBCL (T-DLBCL) is presented in an immune-privileged site of the testis, and the roles of NF-κB pathway signaling, 9p24.1 aberrations, and tumor-infiltrating immune cells, especially immune checkpoint expressing lymphocytes and macrophages, seem to be unique compared to other lymphoma entities. Preliminary data on the use of immune checkpoint inhibitors in the treatment of T-DLBCL are promising and more studies are ongoing.

SMARCA2-NR4A3 is a novel fusion gene of extraskeletal myxoid chondrosarcoma identified by RNA next-generation sequencing

Extraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma of uncertain differentiation, characterized by recurrent chromosomal translocation involving NR4A3 (9q22.33) in more than 90% of cases. Five fusion partners for NR4A3 have been described including: EWSR1 (22q12.2), TAF15 (17q12), FUS (16p11.2), TCF12 (15q21), and TFG (3q12.2). This report describes a patient with an EMC at the dorsum of the right foot. The tumor showed a cord-like and reticular pattern in a background of myxoid matrix. The tumor cells demonstrated an epithelioid morphology with prominent nucleoli. The tumor cells were positive for synaptophysin, GFAP, with focal positivity for CD117, S100, Cam5.2, and NSE, and negative for AE1/3, desmin, and SMA. An RNA next-generation sequencing test showed a SMARCA2-NR4A3 gene fusion which has not been previously reported. The exon 3 of SMARCA2 was fused to exon 3 of NR4A3. This fusion was confirmed by NR4A3 break-apart FISH, although both SMARCA2 (9p24.3) and NR4A3 (9q22.33) are located on chromosome 9. The tumor cells showed retained expression of INI1 and SMARCA2 by immunohistochemistry.

Immune-Checkpoint Inhibitors in B-Cell Lymphoma

Simple Summary

Immune-based treatment strategies, which include immune checkpoint inhibition, have recently become a new frontier for the treatment of B-cell-derived lymphoma. Whereas checkpoint inhibition has given oncologists and patients hope in specific lymphoma subtypes like Hodgkin lymphoma, other entities do not benefit from such promising agents. Understanding the factors that determine the efficacy and safety of checkpoint inhibition in different lymphoma subtypes can lead to improved therapeutic strategies, including combinations with various chemotherapies, biologics and/or different immunologic agents with manageable safety profiles.

Abstract

For years, immunotherapy has been considered a viable and attractive treatment option for patients with cancer. Among the immunotherapy arsenal, the targeting of intratumoral immune cells by immune-checkpoint inhibitory agents has recently revolutionised the treatment of several subtypes of tumours. These approaches, aimed at restoring an effective antitumour immunity, rapidly reached the market thanks to the simultaneous identification of inhibitory signals that dampen an effective antitumor response in a large variety of neoplastic cells and the clinical development of monoclonal antibodies targeting checkpoint receptors. Leading therapies in solid tumours are mainly focused on the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) pathways. These approaches have found a promising testing ground in both Hodgkin lymphoma and non-Hodgkin lymphoma, mainly because, in these diseases, the malignant cells interact with the immune system and commonly provide signals that regulate immune function. Although several trials have already demonstrated evidence of therapeutic activity with some checkpoint inhibitors in lymphoma, many of the immunologic lessons learned from solid tumours may not directly translate to lymphoid malignancies. In this sense, the mechanisms of effective antitumor responses are different between the different lymphoma subtypes, while the reasons for this substantial difference remain partially unknown. This review will discuss the current advances of immune-checkpoint blockade therapies in B-cell lymphoma and build a projection of how the field may evolve in the near future. In particular, we will analyse the current strategies being evaluated both preclinically and clinically, with the aim of fostering the use of immune-checkpoint inhibitors in lymphoma, including combination approaches with chemotherapeutics, biological agents and/or different immunologic therapies.

PD-1/PD-L1 Pathway and Its Blockade in Patients with Classic Hodgkin Lymphoma and Non-Hodgkin Large-Cell Lymphomas

PURPOSE OF REVIEW

Programmed cell death protein-1 (PD-1) is currently the most extensively studied inhibitory checkpoint molecule. Many malignant neoplasms express the PD-1 ligands, PD-L1, and/or PD-L2, which bind to PD-1 on T cells and induce T cell "exhaustion." By doing so, the malignant cells escape from an antitumor immune response (immune evasion). Blockade of the PD-1/PD-L1 pathway releases T cells from the inhibitory effects exerted by tumor cells and restores a T cell-mediated antitumor immune response. Here, we focus on understanding the immune biology of the PD-1/PD-L1 pathway in large-cell lymphomas, including classic Hodgkin lymphoma (CHL), diffuse large B cell lymphoma (DLBCL), and anaplastic large-cell lymphoma (ALCL), and the current status of PD-1 blockade immunotherapy in treating patients with these lymphomas.

RECENT FINDINGS

PD-1/PD-L1 pathway and PD-1 inhibitors have been widely tested in patients with a variety of lymphomas. Nivolumab and pembrolizumab have been approved by the U.S. Food and Drug Administration for treating patients with some types of relapsed or refractory (R/R) lymphomas. The highest response rate has been achieved in patients with CHL, due to a high frequency of genetic alterations of 9p24.1 and high expression of PD-1 ligands. The frequency of alterations of chromosome 9p24.1 and expression of PD-L1/PD-L1 in DLBCL (except some specific subtypes) is low; therefore, it is not recommended to treat unselected DLBCL patients with PD-1 inhibitors. Studies have shown a high frequency of PD-L1 expression in ALCL, especially in anaplastic lymphoma kinase (ALK)+ type. Several cases reports have described a dramatic and durable response to PD-1 blockade in patients with R/R ALCL, suggesting that patients with R/R ALCL may be potential candidates for PD-1 blockade immunotherapy. Understanding the immune biology of lymphoid neoplasms has helped us identify the specific lymphoma types that are vulnerable to PD-1 inhibitors, such as CHL, and specific subtypes of DLBCL. However, our knowledge of many other lymphomas, including ALCL, in this area is still very limited and the future of PD-1 inhibitors in treating those lymphomas remains unclear.

Current Clinical Applications and Future Perspectives of Immune Checkpoint Inhibitors in Non-Hodgkin Lymphoma

Cancer cells escape immune recognition by exploiting the programmed cell-death protein 1 (PD-1)/programmed cell-death 1 ligand 1 (PD-L1) immune checkpoint axis. Immune checkpoint inhibitors that target PD-1/PD-L1 unleash the properties of effector T cells that are licensed to kill cancer cells. Immune checkpoint blockade has dramatically changed the treatment landscape of many cancers. Following the cancer paradigm, preliminary results of clinical trials in lymphoma have demonstrated that immune checkpoint inhibitors induce remarkable responses in specific subtypes, most notably classical Hodgkin lymphoma and primary mediastinal B-cell lymphoma, while in other subtypes, the results vary considerably, from promising to disappointing. Lymphomas that respond to immune checkpoint inhibitors tend to exhibit tumor cells that reside in a T-cell-rich immune microenvironment and display constitutive transcriptional upregulation of genes that facilitate innate immune resistance, such as structural variations of the PD-L1 locus, collectively referred to as T-cell-inflamed lymphomas, while those lacking such characteristics are referred to as noninflamed lymphomas. This distinction is not necessarily a sine qua non of response to immune checkpoint inhibitors, but rather a framework to move the field forward with a more rational approach. In this article, we provide insights on our current understanding of the biological mechanisms of immune checkpoint evasion in specific subtypes of B-cell and T-cell non-Hodgkin lymphomas and summarize the clinical experience of using inhibitors that target immune checkpoints in these subtypes. We also discuss the phenomenon of hyperprogression in T-cell lymphomas, related to the use of such inhibitors when T cells themselves are the target cells, and consider future approaches to refine clinical trials with immune checkpoint inhibitors in non-Hodgkin lymphomas.

Adverse prognostic impact of regulatory T-cells in testicular diffuse large B-cell lymphoma

OBJECTIVES

Testicular diffuse large B-cell lymphoma (T-DLBCL) is a rare and aggressive extranodal lymphoma. We have previously shown that high content of tumor-infiltrating lymphocytes (TILs) and PD-1 expressing TILs associate with better survival in T-DLBCL. In this study, we have further characterized distinct TIL subtypes and their proportions in association with patient demographics and survival.

METHODS

We used multiplex immunohistochemistry to characterize TIL phenotypes, including cytotoxic T-cells (CTLs; CD8⁺ , OX40⁺ , Granzyme B⁺ , Ki-67⁺ , LAG-3⁺ , TIM-3⁺ , PD-1⁺ ), CD4⁺ T-cells (CD3⁺ , CD4⁺ , TIM-3⁺ , LAG-3⁺ ), regulatory T-cells (Tregs; CD3⁺ , CD4⁺ , FoxP3⁺ ), and T helper 1 cells (Th1; CD3⁺ , CD4⁺ , T-bet⁺ ) in 79 T-DLBCLs, and correlated the findings with patient demographics and outcome.

RESULTS

We observed a substantial variation in TIL phenotypes between the patients. The most prominent CD8⁺ TILs were Ki-67⁺ and TIM-3⁺ CTLs, whereas the most prominent CD4⁺ TILs were FoxP3⁺ Tregs. Despite the overall favorable prognostic impact of high TIL content, we found a subpopulation of T-bet⁺ FoxP3⁺ Tregs that had a significant adverse impact on survival. Lower content of CTLs with activated or exhausted phenotypes correlated with aggressive clinical features.

CONCLUSIONS

Our results demonstrate significant variation in TIL phenotypes and emphasize the adverse prognostic impact of Tregs in T-DLBCL.

Novel markers in pediatric-type follicular lymphoma

The aim of this study was to review the histopathological, phenotypic, and molecular characteristics of pediatric-type follicular lymphoma (PTFL) and to assess the diagnostic value of novel immunohistochemical markers in distinguishing PTFL from follicular hyperplasia (FH). A total of 13 nodal PTFLs were investigated using immunohistochemistry, fluorescence in situ hybridization (FISH), and PCR and were compared with a further 20 reactive lymph nodes showing FH. Morphologically, PTFL cases exhibited a follicular growth pattern with irregular lymphoid follicles in which the germinal centers were composed of numerous blastoid cells showing a starry-sky appearance. Immunohistochemistry highlighted preserved CD10 (13/13) and BCL6 (13/13) staining, CD20 (13/13) positivity, a K light chain predominance (7/13), and partial BCL2 expression in 6/13 cases (using antibodies 124, E17, and SP66). The germinal center (GC)–associated markers stathmin and LLT-1 were positive in most of the cases (12/13 and 12/13, respectively). Interestingly, FOXP-1 was uniformly positive in PTFL (12/13 cases) in contrast to reactive GCs in FH, where only a few isolated positive cells were observed. FISH revealed no evidence of BCL2, BCL6, or MYC rearrangements in the examined cases. By PCR, clonal immunoglobulin gene rearrangements were detected in 100% of the tested PTFL cases. Our study confirmed the unique morphological and immunophenotypic features of PTFL and suggests that FOXP-1 can represent a novel useful diagnostic marker in the differential diagnosis between PTFL and FH.

Pembrolizumab for the treatment of diffuse large B-cell lymphoma

Introduction: Pembrolizumab is a novel monoclonal antibody that targets the interaction between programmed cell death protein 1 (PD-1) and its ligand (PD-L1). Pembrolizumab has shown significant clinical efficacy in Hodgkin Lymphoma (HL), but results in non Hodgkin Lymphoma (NHL) are mixed. Some NHL subtypes, which share certain genetic features with HL, such as alterations in chromosome 9p24.1 and expression of PD-L1, have shown promising responses in early phase trials. Areas covered: In this review, we provide an overview of pembrolizumab as a compound, and present the available clinical efficacy and safety data in the treatment of diffuse large B cell lymphomas. Expert opinion: Current early phase data suggest that single agent pembrolizumab in NHL demonstrates both efficacy and a favorable safety profile. However, it is anticipated that future treatment strategies will be biomarker-driven and incorporate pembrolizumab into combination therapies with chemotherapy and/or immunotherapy agents.

Sanctuary site central nervous system relapse-refractory DLBCL responding to nivolumab and lenalidomide

Despite improvement in survival in diffuse large B-cell lymphoma (DLBCL) with the introduction of rituximab, central nervous system (CNS) relapse continues to represent a clinical challenge. In diffuse large B-cell lymphoma (DLBCL), the incidence of CNS relapse is only ∼5% in unselected cohorts. Immunotherapy is the treatment that either boosts the patient's own immune system or uses man-made versions of the normal parts of the immune system to kill lymphoma cells or slow their growth. We are presenting a thirty-eight year old man who, presented with neck nodes, axillary nodes, altered sensorium, abnormal body movements, unconsciousness, weight loss and, fever, with a past history of DLBCL in May 2008, treated with 6 cycles of CHOP and completed in November 2008. After 9 years in April 2018, the patient developed similar symptoms and treated with salvage chemotherapy with R-DHAP which was completed in September 2018. Post-treatment PET-CT showed partial metabolic response and we started external beam radiotherapy to initial bulky disease. After completion of radiotherapy, the patient was very reluctant for any type of therapy and went home. After one month he presented to us with persistent vomiting, abnormal body movements and, altered sensorium. On examination, his Glasgow Coma Scale (GCS) was E2V3M2 and he was admitted in Intensive Care Unit. The patient was managed with mannitol, dexamethasone, antiepileptics, antibiotics and other supportive care medicines. His brain magnetic resonance imaging (MRI) was showing multiple heterogeneously enhancing lesions with surrounding vasogenic oedema and his cerebrospinal fluid analysis was positive for malignant cells. He was managed with triple intrathecal chemotherapy with methotrexate 12 mg, Cytarabine 50 mg, and Hydrocortisone 50 mg along with other supportive care medicines, and after 4-5 days he regained consciousness and he was able to talk and understand verbal commands. In view of improvement in general condition and performance status, we started biweekly triple intra-thecal therapy, and Inj. Nivolumab 3 mg per kg q 2 weekly. From the second cycle, we started Lenalidomide 10 mg once a day for 21 days with 7 days gap along with 2 weekly nivolumab and biweekly triple IT chemotherapy. After one month his CSF analysis was negative for malignant cells. Now he is on regular treatment with weekly IT chemotherapy, 2 weekly nivolumab and 3 weeks on and one week off lenalidomide. After 2 months of treatment, his MRI Brain was showing. At the time of submission of this article, he has completed the fifth cycle of immunotherapy and two cycles of lenalidomide. He was able to manage his daily ADL and able to walk with a stick. The patient tolerated immunotherapy, triple IT therapy and lenalidomide very well without much intolerable side effects. Therefore, we concluded that nivolumab and lenalidomide was well tolerated and exhibited antitumor activity in extensively pretreated patients with relapsed or refractory sanctuary site CNS B- cell lymphomas. Additional studies of Nivolumab and lenalidomide in these diseases are ongoing.

Prevalence of PDL1 Amplification and Preliminary Response to Immune Checkpoint Blockade in Solid Tumors

Importance

Copy number alterations in programmed cell death ligand 1 (PDL1 or CD274), programmed cell death 1 ligand 2 (PDCD1LG2 or PDL2), and Janus kinase 2 (JAK2) genes (chromosome 9p24.1) characterize Hodgkin lymphoma, resulting in high response rates to programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) blockade. The prevalence and utility of PDL1 amplification as a response biomarker to PD-1/PD-L1 blockade are unknown in other tumors.

Objectives

To examine the prevalence of PDL1 amplification and its utility as a response biomarker to PD-1/PD-L1 blockade in solid tumors.

Design, Setting, and Participants

This retrospective study (October 1, 2012, to October 1, 2017) used a deidentified tumor database from a commercial company and annotated clinical records from a subset of patients treated at a university tertiary referral center. The study analyzed 118 187 tumors from the deidentified database, including a clinically annotated subgroup of 2039 malignant tumors.

Interventions

Comprehensive genomic profiling was performed on all samples to determine PDL1 amplification, microsatellite instability, and tumor mutational burden (TMB). A subset of patients was treated with PD-1/PD-L1 blockade.

Main Outcomes and Measures

The prevalence of PDL1 amplification was determined among 118 187 patient samples that underwent next-generation sequencing. Solid tumors treated with checkpoint blockade were evaluated for response and progression-free survival (PFS).

Results

Of the 118 187 deidentified tumor samples, PDL1 amplifications were identified in 843 (0.7%), including more than 100 types of solid tumors. Most PDL1-amplified tumors (84.8%) had a low to intermediate TMB. PDL1 amplification did not always correlate with high-positive PD-L1 expression by immunohistochemical analysis. Six of 9 patients (66.7%) from 1 center with PDL1-amplified solid tumors had objective responses after checkpoint blockade administration. The median PFS among all treated patients was 15.2 months. Responders included 1 patient with glioblastoma (PFS, ≥5.2 months), 2 patients with head and neck squamous cell cancer (PFS, ≥9 and 15.2 months), 2 patients with metastatic basal cell cancer (PFS, 3.8 and ≥24.1 months), and 1 patient with urothelial cancer (PFS, ≥17.8 months).

Conclusions and Relevance

The results of this study suggest that PDL1 amplification occurs in a small subset of malignant tumors. Additional large-scale, prospective studies of PDL1-amplified cancers are warranted to confirm the responses to checkpoint blockade described herein, even in the absence of microsatellite instability, high PD-L1 expression, and a high TMB.

PD-L1+ tumor-associated macrophages and PD-1+ tumor-infiltrating lymphocytes predict survival in primary testicular lymphoma

Primary testicular lymphoma is a rare and aggressive lymphoid malignancy, most often representing diffuse large B-cell lymphoma histologically. Tumor-associated macrophages and tumor-infiltrating lymphocytes have been associated with survival in diffuse large B-cell lymphoma, but their prognostic impact in primary testicular lymphoma is unknown. Here, we aimed to identify macrophages, their immunophenotypes and association with lymphocytes, and translate the findings into survival of patients with primary testicular lymphoma. We collected clinical data and tumor tissue from 74 primary testicular lymphoma patients, and used multiplex immunohistochemistry and digital image analysis to examine macrophage markers (CD68, CD163, and c-Maf), T-cell markers (CD3, CD4, and CD8), B-cell marker (CD20), and three checkpoint molecules (PD-L1, PD-L2, and PD-1). We demonstrate that a large proportion of macrophages (median 41%, range 0.08–99%) and lymphoma cells (median 34%, range 0.1–100%) express PD-L1. The quantity of PD-L1⁺ CD68⁺ macrophages correlates positively with the amount of PD-1⁺ lymphocytes, and a high proportion of either PD-L1⁺ CD68⁺ macrophages or PD-1⁺ CD4⁺ and PD-1⁺ CD8⁺ T cells translates into favorable survival. In contrast, the number of PD-L1⁺lymphoma cells or PD-L1⁻ macrophages do not associate with outcome. In multivariate analyses with IPI, PD-L1⁺ CD68⁺ macrophage and PD-1⁺ lymphocyte contents remain as independent prognostic factors for survival. In conclusion, high PD-L1⁺ CD68⁺ macrophage and PD-1⁺ lymphocyte contents predict favorable survival in patients with primary testicular lymphoma. The findings implicate that the tumor microenvironment and PD-1 – PD-L1 pathway have a significant role in regulating treatment outcome. They also bring new insights to the targeted thera py of primary testicular lymphoma.

Hide or defend, the two strategies of lymphoma immune evasion: potential implications for immunotherapy

Evading immune eradication is a prerequisite for neoplastic progression and one of the hallmarks of cancer. Here, we review the different immune escape strategies of lymphoma and classify them into two main mechanisms. First, lymphoma cells may “hide” to become invisible to the immune system. This can be achieved by losing or downregulating MHC and/or molecules involved in antigen presentation (including antigen processing machinery and adhesion molecules), thereby preventing their recognition by the immune system. Second, lymphoma cells may “defend” themselves to become resistant to immune eradication. This can be achieved in several ways: by becoming resistant to apoptosis, by expressing inhibitory ligands that deactivate immune cells and/or by inducing an immunosuppressive (humoral and cellular) microenvironment. These immune escape mechanisms may have therapeutic implications. Their identification may be used to guide “personalized immunotherapy” for lymphoma.

Secondary CNS relapse in diffuse large B-cell lymphoma: defining high-risk patients and optimization of prophylaxis strategies

Despite improvement in survival in diffuse large B-cell lymphoma (DLBCL) with the introduction of rituximab, central nervous system (CNS) relapse continues to represent a clinical challenge. A number of studies have evaluated clinical risk factors in an attempt to identify high-risk patients to direct CNS staging investigations and consider prophylaxis strategies. The CNS International Prognostic Index is a robust and reproducible risk model that can identity patients at high risk of CNS relapse, but its specificity remains limited. Studies are emerging of biomarkers that predict CNS relapse that can be integrated with clinical risk models to better identify high-risk patients for CNS-directed prophylaxis strategies. Because CNS parenchymal disease is the predominant compartment, prophylaxis should include deeply penetrant drugs such as high-dose methotrexate. However, this has been associated with toxicity and has limited use in older patients. Novel therapies are being tested in primary CNS lymphoma with encouraging results and may represent rational strategies to be further explored in the prophylaxis setting.

Genetic landscape and deregulated pathways in B-cell lymphoid malignancies

With the introduction of next-generation sequencing, the genetic landscape of the complex group of B-cell lymphoid malignancies has rapidly been unravelled in recent years. This has provided important information about recurrent genetic events and identified key pathways deregulated in each lymphoma subtype. In parallel, there has been intense search and development of novel types of targeted therapy that 'hit' central mechanisms in lymphoma pathobiology, such as BTK, PI3K or BCL2 inhibitors. In this review, we will outline the current view of the genetic landscape of selected entities: follicular lymphoma, diffuse large B-cell lymphoma, mantle cell lymphoma, chronic lymphocytic leukaemia and marginal zone lymphoma. We will detail recurrent alterations affecting important signalling pathways, that is the B-cell receptor/NF-κB pathway, NOTCH signalling, JAK-STAT signalling, p53/DNA damage response, apoptosis and cell cycle regulation, as well as other perhaps unexpected cellular processes, such as immune regulation, cell migration, epigenetic regulation and RNA processing. Whilst many of these pathways/processes are commonly altered in different lymphoid tumors, albeit at varying frequencies, others are preferentially targeted in selected B-cell malignancies. Some of these genetic lesions are either involved in disease ontogeny or linked to the evolution of each disease and/or specific clinicobiological features, and some of them have been demonstrated to have prognostic and even predictive impact. Future work is especially needed to understand the therapy-resistant disease, particularly in patients treated with targeted therapy, and to identify novel targets and therapeutic strategies in order to realize true precision medicine in this clinically heterogeneous patient group.

Role of the tumor microenvironment in mature B-cell lymphoid malignancies

The tumor microenvironment is the cellular and molecular environment in which the tumor exists and with which it continuously interacts. In B-cell lymphomas, this microenvironment is intriguing in that it plays critical roles in the regulation of tumor cell survival and proliferation, fostering immune escape as well as the development of treatment resistance. The purpose of this review is to summarize the proceedings of the Second Annual Summit on the Immune Microenvironment in Hematologic Malignancies that took place on September 11-12, 2014 in Dublin, Ireland. We provide a timely overview of the composition and biological relevance of the cellular and molecular microenvironment interface and discuss the role of interactions between the microenvironment and neoplastic cells in a variety of B-cell lymphomas. In addition, we focus on various novel therapeutic strategies that target the tumor microenvironment, including agents that modulate B-cell receptor pathways and immune-checkpoints, chimeric antigen receptor T cells and immunomodulatory agents.

Mechanisms of Immune Tolerance in Leukemia and Lymphoma

The mechanisms through which immune responses are generated against solid cancers are well characterized and knowledge of the immune evasion pathways exploited by these malignancies has grown considerably. However, for hematological cancers, which develop and disseminate quite differently than solid tumors, the pathways that regulate immune activation or tolerance are less clear. Growing evidence suggests that, while numerous immune escape pathways are shared between hematological and solid malignancies, several unique pathways are exploited by leukemia and lymphoma. Below we discuss immune evasion mechanisms in leukemia and lymphoma, highlighting key differences from solid tumors. A more complete characterization of the mechanisms of immune tolerance in hematological malignancies is critical to inform the development of future immunotherapeutic approaches.

[Immune-checkpoint and hemopathies]

Immune-checkpoint inhibitors represent potent new therapies for most lymphomas, particularly for refractory diseases. Contrasting with solid tumors the majority of lymphoma are sensitive to conventional therapies and immunotherapies such as anti-CD20 or anti-CD30. But relapsing lymphoma or refractory disease have a very poor prognosis and new drugs are mandatory. Immune-checkpoint inhibitors targeting CTLA4, PD-1 et PD-L1 demonstrated efficiency with prolonged survivals even after bone marrow allograft for aggressive disease. Lymphomas differ from solid tumors as tumor cells belong to the immune compartment and therefore molecules targeting immune cells may act on both immune environment and tumor cells. Furthermore, PD-L1 expression in most lymphomas is related to tumor cell molecular alterations such as PD-L1 gene amplification or mutation. PD-L1 protein expression on tumor cells and immune cells, particularly it frequency and distribution vary according to different lymphoma subtype and it may help to assess diagnosis as it may predict therapeutical response.

The emerging role of immune checkpoint inhibition in malignant lymphoma

To evade elimination by the host immune system, tumor cells commonly exploit physiological immune checkpoint pathways, restraining efficient anti-tumor immune cell function. Growing understanding of the complex dialog between tumor cells and their microenvironment contributed to the development of immune checkpoint inhibitors. This innovative strategy has demonstrated paradigm-shifting clinical activity in various malignancies. Antibodies targeting programmed death 1 and cytotoxic T-lymphocyte-associated protein-4 are also being investigated in lymphoid malignancies with varying levels of activity and a favorable toxicity profile. To date, evaluated only in the setting of relapsed or refractory disease, anti-programmed death 1 antibodies such as nivolumab and pembrolizumab show encouraging response rates particularly in classical Hodgkin lymphoma but also in follicular lymphoma and diffuse-large B-cell lymphoma. As the first immune checkpoint inhibitor in lymphoma, nivolumab was approved for the treatment of relapsed or refractory classical Hodgkin lymphoma by the Food and Drug Administration in May 2016. In this review, we assess the role of the pathways involved and potential rationale of checkpoint inhibition in various lymphoid malignancies. In addition to data from current clinical trials, immune-related side effects, potential limitations and future perspectives including promising combinatory approaches with immune checkpoint inhibition are discussed.

The significance of FOXP1 in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of mature B-cell lymphoma. While the majority of patients are cured with immunochemotherapy incorporating the anti-CD20 monoclonal antibody rituximab (R-CHOP), relapsed and refractory patients still have a dismal prognosis. DLBCL subtypes including an aggressive activated B-cell-like (ABC) and a more favorable prognosis germinal center-like (GCB) DLBCL have been identified by gene expression profiling and are characterized by distinct genetic abnormalities and oncogenic pathways. This identification of novel molecular targets is now enabling clinical trials to evaluate more effective personalized approaches to DLBCL therapy. The forkhead transcription factor FOXP1 is highly expressed in the ABC-DLBCL gene signature and has been extensively studied within the context of DLBCL for more than a decade. Here, we review the significance of FOXP1 in the pathogenesis of DLBCL, summarizing data supporting its utility as a prognostic and subtyping marker, its targeting by genetic aberrations, the importance of specific isoforms, and emerging data demonstrating a functional role in lymphoma biology. FOXP1 is one of the critical transcription factors whose deregulated expression makes important contributions to DLBCL pathogenesis. Thus, FOXP1 warrants further study as a potential theranostic in ABC-DLBCL.

Comprehensive characterization of programmed death ligand structural rearrangements in B-cell non-Hodgkin lymphomas

Capture sequencing reveals that PDL SRs cluster into 2 discrete breakpoint regions. PDL SRs are significantly associated with increased protein expression and limit T-cell activation.

Genetic basis of PD-L1 overexpression in diffuse large B-cell lymphomas

Translocations between PD-L1 and the IGH locus represent a genetic mechanism of PD-L1 overexpression in DLBCL. Genetic alterations in the PD-L1/PDL-2 locus are mainly associated with the non-GCB subtype of DLBCL.

Genomic alterations of the JAK2 and PDL loci occur in a broad spectrum of lymphoid malignancies

The recurrent 9p24.1 aberrations in lymphoid malignancies potentially involving four cancer-related and druggable genes (JAK2, CD274/PDL1, PDCD1LG2/PDL2, and KDM4C/JMJD2Cl) are incompletely characterized. To gain more insight into the anatomy of these abnormalities, at first we studied 9p24.1 alterations in 18 leukemia/lymphoma cases using cytogenetic and molecular techniques. The aberrations comprised structural (nine cases) and numerical (nine cases) alterations. The former lesions were heterogeneous but shared a common breakpoint region of 200 kb downstream of JAK2. The rearrangements predominantly targeted the PDL locus. We have identified five potential partner genes of PDL1/2: PHACTR4 (1p34), N4BP2 (4p14), EEF1A1 (6q13), JAK2 (9p24.1), and IGL (22q11). Interestingly, the cryptic JAK2-PDL1 rearrangement was generated by a microdeletion spanning the 3'JAK2-5'PDL1 region. JAK2 was additionally involved in a cytogenetically cryptic IGH-mediated t(9;14)(p24.1;q32) found in two patients. This rare but likely underestimated rearrangement highlights the essential role of JAK2 in B-cell neoplasms. Cases with amplification of 9p24.1 were diagnosed as primary mediastinal B-cell lymphoma (five cases) and T-cell lymphoma (four cases). The smallest amplified 9p24.1 region was restricted to the JAK2-PDL1/2-RANBP6 interval. In the next step, we screened 200 cases of classical Hodgkin lymphoma by interphase FISH and identified PDL1/2 rearrangement (CIITA- and IGH-negative) in four cases (2%), what is a novel finding. Forty (25%) cases revealed high level amplification of 9p24.1, including four cases with a selective amplification of PDL1/2. Altogether, the majority of 9p24.1 rearrangements occurring in lymphoid malignancies seem to target the programmed death-1 ligands, what potentiates the therapeutic activity of PD-1 blockade in these tumors. © 2016 Wiley Periodicals, Inc.

Identification of Primary Mediastinal Large B-cell Lymphoma at Nonmediastinal Sites by Gene Expression Profiling

Mediastinal involvement is considered essential for the diagnosis of primary mediastinal large B-cell lymphoma (PMBL). However, we have observed cases of diffuse large B-cell lymphoma (DLBCL) with features of PMBL but without detectable mediastinal involvement. The goal was to assess our previously established gene expression profiling (GEP) signature for PMBL in classifying these cases. In a large series of DLBCL cases, we identified 24 cases with a GEP signature of PMBL, including 9 cases with a submission diagnosis of DLBCL consistent with PMBL (G-PMBL-P) and 15 cases with a submission diagnosis of DLBCL. The pathology reviewers agreed with the diagnosis in the 9 G-PMBL-P cases. Among the other 15 DLBCL cases, 11 were considered to be PMBL or DLBCL consistent with PMBL, 3 were considered to be DLBCL, and 1 case was a gray-zone lymphoma with features intermediate between DLBCL and classical Hodgkin lymphoma. All 9 G-PMBL-P and 9 of the 15 DLBCL cases (G-PMBL-M) had demonstrated mediastinal involvement at presentation. Interestingly, 6 of the 15 DLBCL cases (G-PMBL-NM) had no clinical or radiologic evidence of mediastinal involvement. The 3 subgroups of PMBL had otherwise similar clinical characteristics, and there were no significant differences in overall survival. Genetic alterations of CIITA and PDL1/2 were detected in 26% and 40% of cases, respectively, including 1 G-PMBL-NM case with gain of PDL1/2. In conclusion, PMBL can present as a nonmediastinal tumor without evidence of mediastinal involvement, and GEP offers a more precise diagnosis of PMBL.

Genomic Alterations in CIITA Are Frequent in Primary Mediastinal Large B Cell Lymphoma and Are Associated with Diminished MHC Class II Expression

Primary mediastinal large B cell lymphoma (PMBCL) is an aggressive non-Hodgkin's lymphoma, predominantly affecting young patients. We analyzed 45 primary PMBCL tumor biopsies and 3 PMBCL-derived cell lines for the presence of genetic alterations involving the major histocompatibility complex (MHC) class II transactivator CIITA and found frequent aberrations consisting of structural genomic rearrangements, missense, nonsense, and frame-shift mutations (53% of primary tumor biopsies and all cell lines). We also detected intron 1 mutations in 47% of the cases, and detailed sequence analysis strongly suggests AID-mediated aberrant somatic hypermutation as the mutational mechanism. Furthermore, we demonstrate that genomic lesions in CIITA result in decreased protein expression and reduction of MHC class II surface expression, creating an immune privilege phenotype in PMBCL. In summary, we establish CIITA alterations as a common mechanism of immune escape through reduction of MHC class II expression in PMBCL, with potential implications for future treatments targeting microenvironment-related biology.

FOXP1 suppresses immune response signatures and MHC class II expression in activated B-cell-like diffuse large B-cell lymphomas

The FOXP1 (forkhead box P1) transcription factor is a marker of poor prognosis in diffuse large B-cell lymphoma (DLBCL). Here microarray analysis of FOXP1-silenced DLBCL cell lines identified differential regulation of immune response signatures and major histocompatibility complex class II (MHC II) genes as some of the most significant differences between germinal center B-cell (GCB)-like DLBCL with full-length FOXP1 protein expression versus activated B-cell (ABC)-like DLBCL expressing predominantly short FOXP1 isoforms. In an independent primary DLBCL microarray data set, multiple MHC II genes, including human leukocyte antigen DR alpha chain (HLA-DRA), were inversely correlated with FOXP1 transcript expression (P<0.05). FOXP1 knockdown in ABC-DLBCL cells led to increased cell-surface expression of HLA-DRA and CD74. In R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone)-treated DLBCL patients (n=150), reduced HLA-DRA (<90% frequency) expression correlated with inferior overall survival (P=0.0003) and progression-free survival (P=0.0012) and with non-GCB subtype stratified by the Hans, Choi or Visco-Young algorithms (all P<0.01). In non-GCB DLBCL cases with <90% HLA-DRA, there was an inverse correlation with the frequency (P=0.0456) and intensity (P=0.0349) of FOXP1 expression. We propose that FOXP1 represents a novel regulator of genes targeted by the class II MHC transactivator CIITA (MHC II and CD74) and therapeutically targeting the FOXP1 pathway may improve antigen presentation and immune surveillance in high-risk DLBCL patients.

Signaling pathway and dysregulation of PD1 and its ligands in lymphoid malignancies

Tumor cells evade immune destruction, at least partially, by upregulating inhibitory signals to limit effector T cell activation. Programmed death 1 (PD-1) is one of the most critical co-inhibitory molecules limiting the T-cell antitumor response. PD-1 and its ligands, PD-L1 and PD-L2, are overexpressed by various types of tumors as well as reactive cells in the tumor microenvironment. A growing body of evidence has shown the clinical efficiency and minimal toxicity of PD-1 pathway inhibitors in patients with solid tumors, but the role of these inhibitors in lymphoid malignancies is much less well studied. In this review, we analyze the pathologic role of the PD-1 pathway in most common lymphoid malignancies and we organize the clinical data from clinical trials of PD-1 pathway inhibitors. Several anti-PD-1 regimens have shown encouraging therapeutic effects in patients with relapsed or refractory Hodgkin lymphoma, follicular lymphoma, and diffuse large B-cell lymphoma. Additional progress is needed to foster an improved understanding of the role of anti-PD-1 therapy in reconstituting antitumor immunity in patients with lymphoid malignancies. Upcoming trials will explore the clinical efficiency of combining PD-1 pathway inhibitors and various agents with diverse mechanisms of action and create more therapeutic possibilities for afflicted patients.