Prognostic significance of T-cell or cytotoxic molecules phenotype in classical Hodgkin's lymphoma: a clinicopathologic study

ASTCT and USCLC Clinical Practice Recommendations for Allogeneic Stem Cell Transplant in Mycosis Fungoides and Sézary Syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of cutaneous T-cell lymphoma (CTCL). While MF generally follows an indolent course, a subset of patients will experience progressive and/or treatment-refractory disease. Sézary syndrome is an aggressive CTCL associated with high morbidity and mortality secondary to immune compromise and opportunistic infection. Although allogeneic hematopoietic cell transplant (allo-HCT) is currently the only available potentially curative treatment modality for MF/SS and is included in NCCN and ASTCT treatment guidelines, there is no published guidance regarding referral criteria, timing and allo-HCT approach to help guide clinicians caring for these patients. Delphi survey of 32 specialists in dermatology (n = 9), transplant hematology/oncology (n = 10), non-transplant hematology/oncology (n = 8), and radiation oncology (n = 5) from across the United States. Consensus required agreement of ≥75% of participants. Sixteen consensus statements were generated on four topics: (1) criteria for referral for consideration for allo-HCT, (2) allo-HCT preparative regimens and procedures (3) disease status at the time of allo-HCT, and (4) multidisciplinary management in the pre- and post-transplant settings. These clinical practice guidelines provide a framework for decision-making regarding allo-HCT for MF/SS and highlight areas for future prospective investigation.

Aggressive Mediastinal Lymphomas

The mediastinum contains essentially all major intrathoracic organs except for the lungs. A variety of both benign and malignant tumors can involve the mediastinum, of which lymphoma is the most common malignancy. Compared to secondary mediastinal involvement by systemic lymphomas, primary mediastinal lymphomas are less common with several specific entities that are mainly confined to mediastinal lymph nodes, and/or thymus. This review will summarize the clinical, histologic, immunophenotypic and molecular genetic features of the most common and most aggressive primary mediastinal lymphomas as well as provide suggested immunohistochemistry panels and differential diagnoses.

Epstein-Barr virus-based prognostic model in nodular sclerosis classic Hodgkin lymphoma

The role of Epstein-Barr virus (EBV) in lymphoma cells of nodular sclerosis classic Hodgkin lymphoma (NScHL) is controversial. Our aim was to explore this and establish a clinically feasible model for risk stratification. We interrogated data from 542 consecutive subjects with NScHL receiving ABVD therapy and demonstrated EBV-infection in their lymphoma cells with EBV-encoded small RNAs (EBERs) in situ hybridization. Subjects were divided into training and validation datasets. As data from the training dataset suggested EBERs-positivity was the only independent prognostic factor for both progression-free survival (PFS) and overall survival (OS), we developed corresponding prognostic models based on it. Our models showed excellent performance in both training and validation cohort. These data indicate the close association of EBV infection and the outcomes of persons with NScHL receiving ABVD. Additionally, our newly developed models should help physicians estimate prognosis and select individualized therapy.

T-cell receptor gamma gene rearrangement analysis of classic Hodgkin lymphoma using a BIOMED-2 assay: a paraffin-embedded tissue analysis of one hundred cases

In the new WHO classifications of haematolymphoid tumours (WHO-HAEM5), classic Hodgkin lymphoma (cHL) is categorized into B-cell lymphoid proliferations and lymphomas. Although the majority of Hodgkin Reed-Sternberg (HRS) cells are of germinal center B-cell origin with some defects of B-cell transcription factors, they rarely express T-cell antigens or cytotoxic molecules. Clonality analyses on cHL samples using BIOMED-2 have been reported by several groups; however, those studies were only focused on Ig regions, including IgH, Ig-kappa, and Ig-lambda, and TCR-γ clonality analysis of cHL has not yet been explored. Here, we investigated TCR-γ gene rearrangement for one hundred cases using a PCR-based method. Four of one hundred (4%) cases showed TCR-γ clonal peaks. Of these, three were at an advanced stage and one patient died of the disease. To clarify whether HRS cells showed T-cell clonality or not, we performed PCR analysis using DNAs of microdissected HRS cells. Three samples showed identical clonal peaks with bulk specimens. Our results indicate that cHL is a heterogeneous disease of mainly B-cell and rarely T-cell origin with a special phenotype. Further molecular studies are warranted.

Initial Diagnosis of Classic Hodgkin Lymphoma With Skin Biopsy: A Rare Case and Review of Diagnostic Considerations

ABSTRACT

Classic Hodgkin lymphoma (CHL) is a B-cell-derived lymphoma that classically displays a bimodal age distribution. CHL typically involves the mediastinum, lymph nodes, and other visceral organs. CHL is characterized histologically by the presence of a relatively paucicellular neoplastic cell population composed of large atypical cells (including Hodgkin and Reed-Sternberg forms) in a reactive mixed inflammatory background, often with prominent necrosis. CHL rarely occurs in the skin, and the associated mixed inflammatory infiltrate or necrotic appearance can create diagnostic uncertainty. Herein, we report the case of a 31-year-old man presenting with a painful dendritic rash of the anterior chest wall with axillary lymphadenopathy. After multiple nondiagnostic biopsies that revealed largely necrotic material, a chest wall skin biopsy was obtained. The skin biopsy was diagnostic of CHL, based on the presence of large atypical dermal cells, including Hodgkin and Reed-Sternberg forms, which expressed CD15, CD30 and Fascin, in a typical mixed inflammatory and necrotic background. Through the lens of this case, we discuss the characteristics and mechanisms of skin involvement of CHL, and the histopathologic and immunohistochemical pitfalls when considering the rare diagnosis of CHL in the skin.

Diagnostic approach for classic Hodgkin lymphoma in small samples with an emphasis on PD-L1 expression and EBV harboring in tumor cells: a brief review from morphology to biology

Classic Hodgkin lymphoma (CHL) was first described in 1832 by Thomas Hodgkin, and is characterized by a small number of Hodgkin and Reed-Sternberg cells in a rich inflammatory background. However, even in this modern era, due to the histological and biological overlap with CHL and other B-cell malignancies, including mediastinal grey zone lymphoma and other lymphomas accompanied by "Hodgkinoid cells", their discrimination is challenging and sometimes impossible. The complexity and ambiguity of the boundaries of CHL and its related diseases make the definition of CHL unresolved. Our group has studied the significance of PD-L1 expression and infection of Epstein-Barr virus (EBV) in the diagnosis of CHL, emphasizing their pathological role, clinical significance, and high reproducibility even in daily clinical practice. In this review, we summarize the diagnostic strategy of CHL and its histological lookalikes based on neoplastic PD-L1 expression and infection of EBV, and attempt a reappraisal of the definition of CHL.

The prognostic value of Epstein-Barr virus infection in Hodgkin lymphoma: A systematic review and meta-analysis

INTRODUCTION

Epstein-Barr virus (EBV) contributes significantly to the development and occurrence of B-cell lymphomas. However, the association between EBV infection status and clinical outcomes in Hodgkin lymphoma (HL) patients has long been controversial. Therefore, we aimed to estimate the prognostic significance of EBV infection in HL survival.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library for relevant cohort studies from the date of their inception to February 20, 2022. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS), Failure-free survival (FFS), Progression-free survival (PFS), Event-free survival (EFS) and disease-specific survival (DSS) were extracted from the studies or calculated. Subgroup analyses were conducted independently on the five survival outcomes to investigate the source of heterogeneity.

RESULTS

A total of 42 qualified studies involving 9570 patients were identified in our meta-analysis. There was an association between EBV positivity and significantly poorer OS (HR=1.443, 95% CI: 1.250-1.666) and DSS (HR=2.312, 95% CI: 1.799-2.972). However, the presence of EBV in HL showed no effect on FFS, PFS or EFS. In subgroup analyses of OS, DSS and FFS stratified by age groups, EBV positivity was associated with poorer prognosis in elderly patients. Meanwhile, in children and adolescents with EBV-positive HL, we also observed a trend toward a better prognosis, though the results were not statistically significant.

CONCLUSIONS

EBV-positive status is associated with poor OS and DSS in HL patients. EBV infection should therefore be considered a valuable prognostic marker and risk-stratifying factor in HL, especially in older patients.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022328708.

An Update on the Pathology and Molecular Features of Hodgkin Lymphoma

Simple Summary

Hodgkin lymphomas (HLs) include two main types, classic HL (CHL) and nodular lymphocyte predominant HL (NLPHL). Recent molecular findings in HLs have contributed to dramatic changes in the treatment and identification of tumor characteristics. For example, PD-1/PD-L1 blockade and brentuximab vedotin, an anti-CD30 antibody bearing a cytotoxic compound, are now widely used in patients with CHL. Biological continuity between NLPHL and T-cell/histiocyte-rich large B-cell lymphoma has been highlighted. An era of novel therapeutics for HL has begun. The aim of this paper is to review the morphologic, immunophenotypic, and molecular features of CHL and NLPHL, which must be understood for the development of novel therapeutics.

Abstract

Hodgkin lymphomas (HLs) are lymphoid neoplasms derived from B cells and consist histologically of large neoplastic cells known as Hodgkin and Reed–Sternberg cells and abundant reactive bystander cells. HLs include two main types, classic HL (CHL) and nodular lymphocyte predominant HL (NLPHL). Recent molecular analyses have revealed that an immune evasion mechanism, particularly the PD-1/PD-L1 pathway, plays a key role in the development of CHL. Other highlighted key pathways in CHL are NF-κB and JAK/STAT. These advances have dramatically changed the treatment for CHL, particularly relapsed/refractory CHL. For example, PD-1 inhibitors are now widely used in relapsed/refractory CHL. Compared with CHL, NLPHL is more characterized by preserved B cell features. Overlapping morphological and molecular features between NLPHL and T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) have been reported, and biological continuity between these two entities has been highlighted. Some THRLBCLs are considered to represent progression from NLPHLs. With considerable new understanding becoming available from molecular studies in HLs, therapies and classification of HLs are continually evolving. This paper offers a summary of and update on the pathological and molecular features of HLs for a better understanding of the diseases.

The Prognostic Significance of PD1 and PDL1 Gene Expression in Lung Cancer: A Meta-Analysis

Background

Immune checkpoint blockade therapy represents an extraordinary advance in lung cancer treatment. It is important to determine the expression of immune checkpoint genes, such as programmed cell death 1 (PD1) and programmed cell death-ligand 1 (PDL1), to develop immunotherapeutic strategies. The aim of this study was to explore the association between PD1 and PDL1 gene expression and prognoses and outcomes in lung cancer.

Methods

This meta-analysis analyzed 1,251 patients from eight different microarray gene expression datasets and were evaluated for their prognostic implications and verified using another independent research.

Results

The mean expression levels of PDL1 in adenocarcinoma (AD) and squamous cell carcinoma (SC) were significantly higher in patients who died than in patients who did not. There was a trend toward incremental increases in PD1 and PDL1 expression significantly decreasing the risk of relapse and death among AD patients (HR = 0.69; 95% CI = 0.53 ~ 0.91; HR = 0.68; 95% CI = 0.54 ~ 0.84, respectively) and SC patients (HR = 0.53; 95% CI = 0.32 ~ 0.89; HR = 0.78; 95% CI = 0.57 ~ 1.00 respectively), as early-stage patients in this study were more likely to have high expression of both PD1 and PDL1 than late-stage patients (P-trend < 0.05). In contrast, late-stage SC patients expressing one or more of the genes at a high level had a significantly elevated risk of relapse (HR = 1.51; 95% CI = 1.07 ~ 2.11) and death (HR = 1.41; 95% CI = 1.08 ~ 1.84). This result was consistent with the validation data set.

Conclusion

These findings indicate that high expression of PD1 and PDL1 is associated with superior outcome in early-stage lung cancer but an adverse outcome in late-stage lung cancer. The expression levels of PD1 and PDL1 individually or jointly are potential prognostic factors for predicting patient outcomes in lung cancer.

Clinicopathological features of syncytial variant nodular sclerosis Hodgkin lymphoma

The syncytial variant of nodular sclerosis Hodgkin lymphoma (SV-NSHL) is uncommon, and its clinicopathological features have not been well analyzed. In this study, we collected 142 cases of SV-NSHL. There were 76 (53.5%) males and 66 (46.5%) females with a median age of 28 years (range, 12-78); 59.9% were younger than 30 years. Patients usually presented with a mediastinal mass (97.6%) and often with bulky (35.7%) and advanced stage disease (3 or 4) (39.7%). Follow-up showed that 61.1% of patients developed relapse after standard therapy. Morphologically, the neoplasms were composed of sheets or large clusters of pleomorphic neoplastic cells with a cohesive appearance that were frequently associated with necrosis. Neutrophils and eosinophils were frequent in the background, whereas small lymphocytes were decreased. Immunohistochemical analysis showed that the following markers were frequently positive: CD30 (100%), MUM1/IRF4 (96%), PAX5 (95%), PD-L1 (91%), and CD15 (80%). CD45 was negative in all cases. Epstein-Barr virus-encoded small RNA (EBER) was detected in 19% of cases. In this cohort, age above 30 years (P = .0430), presence of B-type symptoms (P = .0394), elevated serum lactate dehydrogenase level (P = .0004), and disease relapse (P = .0108) were associated with a poorer overall survival. In contrast, patients with EBER-positive neoplasms had a better survival (P = .0418). Compared with a control group of non-SV-NSHL patients, patients with SV-NSHL were associated with a poorer overall survival (P = .011). These data suggest that SV morphology is associated with a poorer prognosis in patients treated with traditional standard-of-care therapy for classic Hodgkin lymphoma.

Latent Epstein-Barr virus infection status and prognosis in patients with newly diagnosed Hodgkin lymphoma in Southeast China: a single-center retrospective study

PURPOSE

This study aimed to investigate the latent Epstein-Barr virus (EBV) infection status of patients with newly diagnosed Hodgkin lymphoma (HL) and to discuss the relationship between tumor cell EBV status and the prognosis of HL patients.

PATIENTS AND METHODS

A total of 134 previously untreated HL patients were analyzed in the study. Epstein-Barr virus encoded RNAs (EBERs) in situ hybridization was performed to detect the EBV status of tumor cells.

RESULTS

EBV positive status correlated with sex (p=0.046) and the proportion of extranodal lesions(p=0.037). There was no obvious correlation between EBV status and overall survival (OS) or failure-free survival (FFS) in all cases, but in cases over 50 years old, EBV positive group had an inferior 5-year FFS compared with EBV negative group (38.5%±13.5% vs 90.9%±8.7%, p=0.012). In FFS multivariate analysis of this age subgroup, EBV positive status was associated with significantly inferior survival (HR, 10.10; 95% CI, 1.26-81.08; p=0.030).

CONCLUSION

This study demonstrates positive tumor cell EBV status is an unfavorable prognostic factor in elder HL patients.

Dose-dense brentuximab vedotin plus ifosfamide, carboplatin, and etoposide for second-line treatment of relapsed or refractory classical Hodgkin lymphoma: a single centre, phase 1/2 study

BACKGROUND

Relapsed or refractory classical Hodgkin lymphoma could be treated with multiagent salvage chemotherapy followed by autologous haematopoietic stem-cell transplantation. The aim of this study is to establish the safety and activity of dose-dense brentuximab vedotin combined with ifosfamide, carboplatin, and etoposide (BV-ICE) chemotherapy in second-line treatment of classical Hodgkin lymphoma.

METHODS

We conducted a single-arm, open-label, phase 1/2 study of dose-dense BV-ICE at the Seattle Cancer Care Alliance, University of Washington (Seattle, WA, USA). Eligibility criteria were age 18 years or older; diagnosis of first relapse, primary refractory classical Hodgkin lymphoma after one previous line of therapy; measurable disease of at least 1 cm in the longest axis, CT of chest, abdomen, and pelvis with PET within the past 28 days; Eastern Cooperative Oncology Group performance status of 0-1; and adequate organ function. A 3 + 3 dose escalation study was done for the phase 1 part of the trial to establish the maximum tolerated dose to be used for the phase 2 study. Brentuximab vedotin was delivered on days 1 and 8 at either 1·2 mg/kg (dose level 1) or 1·5 mg/kg (dose level 2) intravenously (capped at 150 mg) with standard dosing of ICE on days 1-3 (ifosfamide 5 g/m² plus mesna 5 g/m² intravenously over 24 h on day 2, carboplatin area under the curve 5 on day 2 in one intravenous injection, and etoposide 100 mg/m² on days 1-3 in one intravenous injection per day) for two 21-day cycles. The primary endpoint was to establish the recommended phase 2 dose (phase 1 part) and complete response rate after two cycles, with a prespecified target of 78% (phase 2 part). Safety analysis was done in all enrolled participants and the primary activity analysis was done in all patients with evaluable response data. This study is registered with ClinicalTrials.gov (NCT02227199); enrolment and study treatment are complete.

FINDINGS

Between Oct 16, 2014, and Feb 10, 2020, we enrolled 45 patients with a median age of 31 years (IQR 28-45). The recommended phase 2 dose of brentuximab vedotin was established to be 1·5 mg/kg. After a median follow-up of 3·1 years (IQR 1·7-4·1), 32 (74%; 95% CI 58·8-86·5) of 43 evaluable patients had complete responses after two cycles of treatment. Grade 3-4 haematological toxic effects were common, including neutropenia (33 [73%]), anaemia (six [13%]), and thrombocytopenia (36 [80%]). The most common grade 3-4 non-haematological toxic effects were febrile neutropenia (four [9%]), sepsis (six [13%]), increased alanine aminotransferase (five [11%]), hyperglycaemia (three [7%]), pulmonary embolism (two [4%]), and increased aspartate aminotransferase (two [4%]). There was one (2%) on-treatment death due to multisystem organ failure that was considered treatment related. Serious adverse events occurred in 13 (29%) patients.

INTERPRETATION

Our data suggest that dose-dense BV-ICE is a rapidly administered and active salvage regimen for patients with relapsed or refractory classical Hodgkin lymphoma despite a complete response in this trial lower than the prespecified phase 2 target. Although cross-trial comparisons should be made with caution, activity results seem to be similar to previously presented brentuximab vedotin chemotherapy salvage combinations delivered over much longer durations and can be considered in young (<60 years), transplantation-eligible patients for second-line therapy.

FUNDING

Seagen, Lymphoma Research Foundation, National Institutes of Health/National Cancer Institute, and generous philanthropic donations to the University of Washington from numerous individuals and families in support of lymphoma research.

Syncytial variant of nodular sclerosis Hodgkin lymphoma: an under-emphasized variant

Syncytial variant nodular sclerosis Hodgkin lymphoma (HL) is a variant that was described over 40 years ago but has received relatively little attention in the literature. Earlier studies emphasized the predominance of Hodgkin (also known as lacunar) and Reed-Sternberg (HRS) cells in this variant. Here we emphasize that the HRS cells in syncytial variant nodular sclerosis HL have a cohesive appearance, form confluent sheets, and have an immunophenotype typical of classic HL. Cases of syncytial variant nodular sclerosis HL are also commonly associated with necrosis and granulocytes in the background. Patients with syncytial variant nodular sclerosis HL tend to be young adults who present with lymphadenopathy (most often cervical) and/or a mediastinal mass. The few studies of syncytial variant nodular sclerosis HL available in the literature have suggested that this variant is associated with a higher frequency of B-type symptoms and advanced-stage disease, and one study has suggested that patients have a shorter progression-free survival than patients with typical nodular sclerosis HL. However, currently patients with syncytial variant nodular sclerosis HL are treated similarly to patients with typical nodular sclerosis HL. The large number of neoplastic cells in syncytial variant nodular sclerosis HL cases presents a diagnostic challenge, and the differential diagnosis includes non-Hodgkin lymphomas, other types of classic HL, gray zone lymphoma, thymoma and metastatic neoplasms to the mediastinum including germ cell tumors, carcinomas, and melanoma.

Granzyme B in Inflammatory Diseases: Apoptosis, Inflammation, Extracellular Matrix Remodeling, Epithelial-to-Mesenchymal Transition and Fibrosis

Inflammation is strictly interconnected to anti-inflammatory mechanisms to maintain tissue homeostasis. The disruption of immune homeostasis can lead to acute and chronic inflammatory diseases, as cardiovascular, pulmonary, metabolic diseases and cancer. The knowledge of the mechanisms involved in the development and progression of these pathological conditions is important to find effective therapies. Granzyme B (GrB) is a serine protease produced by a variety of immune, non-immune and tumor cells. Apoptotic intracellular and multiple extracellular functions of GrB have been recently identified. Its capability of cleaving extracellular matrix (ECM) components, cytokines, cell receptors and clotting proteins, revealed GrB as a potential multifunctional pro-inflammatory molecule with the capability of contributing to the pathogenesis of different inflammatory conditions, including inflammaging, acute and chronic inflammatory diseases and cancer. Here we give an overview of recent data concerning GrB activity on multiple targets, potentially allowing this enzyme to regulate a wide range of crucial biological processes that play a role in the development, progression and/or severity of inflammatory diseases. We focus our attention on the promotion by GrB of perforin-dependent and perforin-independent (anoikis) apoptosis, inflammation derived by the activation of some cytokines belonging to the IL-1 cytokine family, ECM remodeling, epithelial-to-mesenchymal transition (EMT) and fibrosis. A greater comprehension of the pathophysiological consequences of GrB-mediated multiple activities may favor the design of new therapies aim to inhibit different inflammatory pathological conditions such as inflammaging and age-related diseases, EMT and organ fibrosis.

Secretome analysis reveals upregulated granzyme B in human androgen-repressed prostate cancer cells with mesenchymal and invasive phenotype

Epithelial-mesenchymal transition (EMT) is a critical early step in cancer metastasis and a complex process that involves multiple factors. In this study, we used proteomics approaches to investigate the secreted proteins (secretome) of paired human androgen-repressed prostate cancer (ARCaP) cell lines, representing the epithelial (ARCaP-E) and mesenchymal (ARCaP-M) phenotypes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses showed high levels of proteins involved in bone remodeling and extracellular matrix degradation in the ARCaP-M cells, consistent with the bone metastasis phenotype. Furthermore, LC-MS/MS showed a significantly higher level of the serine protease granzyme B (GZMB) in ARCaP-M conditioned media (CM) compared to that of ARCaP-E. Using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) to detect mRNA and Western blot to detect protein expression, we further demonstrated that the GZMB gene was expressed by ARCaP-M and the protein was secreted extracellularly. ARCaP-M cells with GZMB gene knockdown using small interfering RNA (siRNA) have markedly reduced invasiveness as demonstrated by the Matrigel invasion assay in comparison with the scrambled siRNA negative control. This study reports that GZMB secretion by mesenchymal-like androgen-repressed human prostate cancer cells promotes invasion, suggesting a possible extracellular role for GZMB in addition to its classic role in immune cell-mediated cytotoxicity.

PD-L1 expression on tumor or stromal cells of nodal cytotoxic T-cell lymphoma: A clinicopathological study of 50 cases

Inhibitors of programmed cell-death 1 (PD-1) and programmed cell-death ligand 1 (PD-L1) have revolutionized cancer therapy. Nodal cytotoxic T-cell lymphoma (CTL) is characterized by a poorer prognosis compared to nodal non-CTLs. Here we investigated PD-L1 expression in 50 nodal CTL patients, with and without EBV association (25 of each). We identified seven patients (14%) with neoplastic PD-L1 (nPD-L1) expression on tumor cells, including three males and four females, with a median age of 66 years. One of the seven cases was TCRαβ type, three were TCRγδ type and three were TCR-silent type. Six of the seven cases exhibited a lethal clinical course despite multi-agent chemotherapy, of whom four patients died within one year of diagnosis. Morphological findings were uniform, with six cases showing centroblastoid appearance. Among nPD-L1+ cases, two of three examined had structural variations of PD-L1 disrupting 3'-UTR region. Notably, all of the TCRγδ-type nodal CTL cases showed nPD-L1 or miPD-L1 positivity (3 and 10 cases, respectively). TCRγδ-type cases comprised 42% of nPD-L1+ cases (P = 0.043 vs. PD-L1- ), and 35% of miPD-L1+ cases (P = 0.037 vs. PD-L1- ). The results indicate that PD-L1+ nodal CTL cases, especially of the TCRγδ type, are potential candidates for anti-PD-1/PD-L1 therapies.

Histology of pediatric classic Hodgkin lymphoma: From diagnosis to prognostic stratification

AIMS

Classic Hodgkin lymphoma (cHL) is a common malignancy of the pediatric age. Although clinical-radiological features are routinely used for disease risk stratification, the role of tumor histology has yet to be defined. This study aimed to characterize the clinical-pathological features of a large cohort of pediatric cHL specifically investigating the relevance of tumor histology for the prognostic stratification of patients.

METHODS AND RESULTS

The study considered 96 clinically annotated cases of pediatric cHL treated according to the AIEOP-LH2004 protocol. The following histological parameters were considered: (i) cHL variant; (ii) grade of nodular sclerosis (NS); (iii) staining for Bcl2 and p53, and expression of B-cell (BCA) and T-cell antigens (TCA) by Hodgkin/Reed-Sternberg cells. The study population consisted of 51 males and 45 females (median age: 13.6 years) with five-year overall and progression-free survival of 94% and 81%, respectively. Most cases featured NS morphology (96%) with a prevalence of NS1 over NS2 grades. Two NS2 variants were recognized (sarcomatous/syncytial and fibrohistiocytic). A consistent subset of cases disclosed positivity for BCA (34%), TCA (26%), p53 (13%), and Bcl2 (19%). Clinical-pathological correlations showed a more aggressive clinical course for NS2 over NS1 cases. The NS2 fibrohistiocytic variant was associated with the worst outcome. No other histological features correlated with prognosis.

CONCLUSIONS

Pediatric cHL is a clinically and histologically heterogeneous neoplasm. The majority of cases disclose NS morphology and aberrant phenotypes are frequently encountered. In the pediatric population, NS grading and NS2 subtyping bear significant prognostic impact.

Relapse or refractory Hodgkin lymphoma: determining risk of relapse or progression after autologous stem-cell transplantation

The treatment of classic Hodgkin lymphoma (HL) is a success in onco-hematology. Despite the high cure rate of HL with initial therapy, 5-10% of patients are primary refractory and 10-20% will eventually relapse. The standard treatment for these patients is salvage chemotherapy and autologous stem cell transplantation (ASCT). Only about half of these patients will benefit from this procedure. The prognosis of relapsed refractory (rr) HL has improved with the introduction of effective drugs. With these options available, identification of reliable risk factors is important to guide treatment over the course of disease. Different variables including performance status, anemia, B symptoms, laboratory abnormalities, treatment intensity before ASCT, response to therapy, and duration of remission, have been analyzed to determine risk for progression-free survival (PFS) and overall survival (OS) after ASCT. This review will discuss the publications analyzing these factors, the validated risk scores useful to identify patients at high risk of progression after ASCT, and will describe future perspectives.

Diagnosis of Hodgkin lymphoma in the modern era

The Hodgkin lymphomas are a family of unique lymphoma subtypes, in which the nature of the neoplastic cell was enigmatic for many years. Much of the mystery has been solved, with all forms now considered to be of B-cell origin, in most cases of germinal centre derivation. Today we recognize Hodgkin lymphoma as an eponym that encompasses multiple entities. One of the unifying themes is the major contribution from the tumour microenvironment. Both the character of the neoplastic cells and the nature of the immune environment are critical to accurate diagnosis. Moreover, an understanding of the molecular alterations that characterize both the neoplastic cells and their microenvironment have led to therapeutic advances, targeting both neoplastic and reactive components. Other conditions may foster a similar inflammatory milieu and lead to lymphoproliferations that mimic the Hodgkin lymphomas. In this review we provide an update on the diagnostic features of the various subtypes and include additional information relevant for prognostic evaluation and investigation of potential therapeutic targets. Additionally, we also discuss those conditions that often cause confusion in diagnosis and need to be distinguished from the Hodgkin lymphomas.

Classical Hodgkin Lymphoma With Aberrant CD8 Expression: A Clinicopathologic Study of Five Cases

Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (CHL) are of B-cell origin. In a small number of CHL cases, the tumor cells can express T-cell antigens. CD8 expression in this setting is extremely rare. We identified 5 cases of CHL with aberrant CD8 expression from our database. The patients included 3 men and 2 women with a median age of 33 years (range = 20-59 years). All the patients initially presented with lymphadenopathy and variable number of RS cells. Two cases were classified as mixed cellularity type that showed prominent vascular proliferation mimicking peripheral T-cell lymphoma. Two cases represented nodular sclerosis type. The tumor cells in all cases were positive for CD8 and negative for CD2, CD3, CD4, and CD7 and carried germline T-cell receptor genes. Molecular studies revealed T-cell receptor genes to be in germline configuration in 4 cases with available information. Given the morphologic overlap with peripheral T-cell lymphoma and the rarity of this type of CHL, identifying more cases will help our better understanding of this entity.

Prognostic value of programmed cell death protein 1 expression on CD8+ T lymphocytes in pancreatic cancer

Pancreatic cancer is one of the most aggressive malignancies and has a highly immunosuppressive tumour microenvironment. Immune checkpoint blockade has led to remarkable and durable objective responses in a number of malignancies and antibody-based strategies targeting programmed cell death protein 1 (PD-1) are showing promise where traditional modalities of surgery, radiotherapy, and chemotherapy have failed. In this study, we examined the clinical value of PD-1 protein expression by CD8+ peripheral T lymphocytes or tumour-infiltrating T lymphocytes (TILs) in pancreatic ductal adenocarcinoma (PDAC). Expression of PD-1 protein on CD8+ TILs correlated with overall survival and clinicopathological characteristics such as clinical stage, N classification, and M classification. Similar findings were observed for the expression of PD-1 protein on peripheral CD8+ T cells, whereas its expression on peripheral CD4+ T cells showed no significance. Comparison of the levels of PD-1 protein expressed by peripheral CD8+ T cells before and 4 weeks after surgery indicated that preoperative and postoperative status of peripheral PD-1 expression was unchanged. Our findings showed that PD-1 protein expressed by peripheral or tumour-infiltrated CD8+ T cells was a promising biomarker for diagnosis and prognosis in PDAC and might help guide future immunotherapies.

Expression of TIA1 and PAX5 in Classical Hodgkin Lymphoma at Initial Diagnosis May Predict Clinical Outcome

Although the expression of T-cell antigens and proteins associated with tumor-infiltrating T-lymphocytes (TILs), regulatory T cells (T-regs), and B-cell development have been evaluated in classical Hodgkin lymphoma (cHL), few studies correlate these proteins' expression patterns with clinical outcome. The purpose of this study was to evaluate proteins expressed in the Reed-Sternberg cells (RSCs) and TILs of cHLs at initial diagnosis to determine their prognostic significance. The expression of 12 proteins in RSCs and TILs from 88 diagnostic cHL biopsies was quantitated and correlated to overall survival (OS) and progression-free survival (PFS). CD2, CD3, CD4, CD5, CD7, CD25, PD1, TIA1, MUM1, and ZAP70 expression in RSCs did not correlate with OS or PFS, nor did programmed death 1 (PD1) expression in TILs. High numbers of TIA1-positive TILs (≥50%) correlated with OS (P=0.027), but not PFS (P=0.993) in univariate analysis. Expression of CD2, CD3, CD4, CD5, and/or TIA1 (6%) in RSCs was associated with lymphocyte-rich/mixed-cellularity subtype (P=0.032). High International Prognostic Score (IPS; P=0.036), and high stage (P=0.046) were independent predictors of worse PFS in univariate analysis. Low IPS (P=0.003) and nodular sclerosing subtype (P=0.022) were associated with better OS in univariate analysis. Only the IPS predicted OS in multivariate (P=0.009) analysis. High TIA1+ TILs correlated with worse clinical outcomes for cHLs, as did PAX5-RSCs (P=0.024), although only 2/74 cases were shown to be negative for this marker, suggesting that the tumor microenvironment and a transcription factor crucial for B-cell development are critical biological determinants of the disease course.

Establishment and characterization of a novel Hodgkin lymphoma cell line, AM-HLH, carrying the Epstein-Barr virus genome integrated into the host chromosome

We describe the establishment and characterization of a cell line, AM-HLH, obtained from a patient with Epstein-Barr virus-positive (EBV⁺ ) nodular sclerosis-type Hodgkin lymphoma (HL). The cells were positive for CD2 and CD30 and negative for CD15. The immunoglobulin heavy- and κ light-chain genes were rearranged. The karyotype was of the triploid range. Southern blotting using the EBV terminal repeat probe detected 3 hybridizing bands that were identical to those of the parental HL material. The cells expressed EBV-encoded RNAs as well as latent genes (EBNA1, EBNA2, LMP1, and LMP2A) and lytic genes (BZLF1 and BALF2). Fluorescence in situ hybridization (FISH) with the cosmid pJB8 clone containing a fragment of EBV DNA as a probe revealed multiple hybridization signals at a marker chromosome. Additional FISH using whole chromosome painting and centromere probes in combination with multicolor FISH determined that multiple EBV copies were clustered within the chromosome 20 materials of the marker chromosome. Culture supernatants of AM-HLH contained IL-10 as measured by the bead-based immunoassay. It is possible that an integrated EBV genome and cellular genes on chromosome 20 were coamplified, leading to the enhanced expression of genes involved in cell growth control. The AM-HLH cell line will be useful to clarify the role of cytokines in the development of EBV⁺ HL.

Tumor-Infiltrating Macrophages in Post-Transplant, Relapsed Classical Hodgkin Lymphoma Are Donor-Derived

Tumor-associated inflammatory cells in classical Hodgkin lymphoma (CHL) typically outnumber the neoplastic Hodgkin/Reed-Sternberg (H/RS) cells. The composition of the inflammatory infiltrate, particularly the fraction of macrophages, has been associated with clinical behavior. Emerging work from animal models demonstrates that most tissue macrophages are maintained by a process of self-renewal under physiologic circumstances and certain inflammatory states, but the contribution from circulating monocytes may be increased in some disease states. This raises the question of the source of macrophages involved in human disease, particularly that of CHL. Patients with relapsed CHL following allogeneic bone marrow transplant (BMT) provide a unique opportunity to begin to address this issue. We identified 4 such patients in our archives. Through molecular chimerism and/or XY FISH studies, we demonstrated the DNA content in the post-BMT recurrent CHL was predominantly donor-derived, while the H/RS cells were derived from the patient. Where possible to evaluate, the cellular composition of the inflammatory infiltrate, including the percentage of macrophages, was similar to that of the original tumor. Our findings suggest that the H/RS cells themselves define the inflammatory environment. In addition, our results demonstrate that tumor-associated macrophages in CHL are predominantly derived from circulating monocytes rather than resident tissue macrophages. Given the association between tumor microenvironment and disease progression, a better understanding of macrophage recruitment to CHL may open new strategies for therapeutic intervention.

Epitelial-to-mesenchimal transition and invasion are upmodulated by tumor-expressed granzyme B and inhibited by docosahexaenoic acid in human colorectal cancer cells

BACKGROUND

Granzyme B (GrB) is a serine protease, traditionally known as expressed by cytotoxic lymphocytes to induce target cell apoptosis. However, it is emerging that GrB, being also produced by a variety of normal and neoplastic cells and potentially acting on multiple targets, might represent a powerful regulator of a wide range of fundamental biological processes. We have previously shown that GrB is expressed in urothelial carcinoma tissues and its expression is associated to both pathological tumor spreading and EMT. We have also shown that docosahexaenoic acid (DHA), a dietary ω-3 polyunsaturated fatty acid with anti-tumor activity, while inhibiting urothelial and pancreatic carcinoma cell invasion also inhibited their GrB expression in vitro. In this study, we characterized a panel of colorectal carcinoma (CRC) cells, with different invasive capabilities, for GrB expression and for the contribution of GrB to their EMT and invasive phenotype. In addition, we investigated the effect of DHA on CRC cell-associated GrB expression, EMT and invasion.

METHODS

The expression levels of GrB and EMT-related markers were evaluated by Western blotting. GrB knockdown was performed by Stealth RNAi small interfering RNA silencing and ectopic GrB expression by transfection of human GrB vector. Cell invasion was determined by the BioCoat Matrigel invasion chamber test.

RESULTS

GrB was produced in 57.1% CRC cell lines and 100% CRC-derived Cancer Stem Cells. Although GrB was constitutive expressed in both invasive and noninvasive CRC cells, GrB depletion in invasive CRC cells downmodulated their invasion in vitro, suggesting a contribution of GrB to CRC invasiveness. GrB loss or gain of function downmodulated or upmodulated EMT, respectively, according to the analysis of cancer cell expression of three EMT biomarkers (Snail1, E-cadherin, N-cadherin). Moreover, TGF-β1-driven EMT was associated to the enhancement of GrB expression in CRC cell lines, and GrB depletion led to downmodulation of TGF-β1-driven EMT. In addition, DHA inhibited GrB expression, EMT and invasion in CRC cells in vitro.

CONCLUSIONS

These findings present a novel role for GrB as upmodulator of EMT in CRC cells. Moreover, these results support the use of DHA, a dietary compound without toxic effects, as adjuvant in CRC therapy.

From mice to humans: developments in cancer immunoediting

Cancer immunoediting explains the dual role by which the immune system can both suppress and/or promote tumor growth. Although cancer immunoediting was first demonstrated using mouse models of cancer, strong evidence that it occurs in human cancers is now accumulating. In particular, the importance of CD8+ T cells in cancer immunoediting has been shown, and more broadly in those tumors with an adaptive immune resistance phenotype. This Review describes the characteristics of the adaptive immune resistance tumor microenvironment and discusses data obtained in mouse and human settings. The role of other immune cells and factors influencing the effector function of tumor-specific CD8+ T cells is covered. We also discuss the temporal occurrence of cancer immunoediting in metastases and whether it differs from immunoediting in the primary tumor of origin.

Prognostic significance of CD20 expression and Epstein-Barr virus (EBV) association in classical Hodgkin lymphoma in Japan: a clinicopathologic study

To investigate the clinicopathological significance of CD20 expression and Epstein-Barr virus (EBV) association in Hodgkin and Reed-Sterberg cells of classical Hodgkin lymphoma (CHL), CD20 expression and EBV positivity (by EBER in situ hybridization) were investigated in 389 CHL patients in Japan. They included 74 CD20-positive cases (19%) and 315 CD20-negative cases (81%). CD20-positive cases showed significantly older age at onset (P = 0.018) and higher association with EBV (P = 0.002). Multivariate analysis identified EBV-positivity (but not CD20-positivity), presence of B symptoms, thrombocytopenia, elevated serum lactate dehydrogenase and performance status >1 as poor prognostic factors for overall survival (OS). We constructed a new prognostic model with these five factors classifying patients into three groups: low risk, 0-1 adverse factor; intermediate risk, 2-3 factors; high risk, 4-5 factors. This prognostic model could stratify the prognosis of CHL patients (P < 0.0001). For 144 patients (58%) classified into the low-risk group, the 5-year OS was 91%. For 92 patients (37%) in the intermediate group, the 5-year OS was 66%; for 11 patients (5%) in the high-risk group, the 5-year OS was 36%. In conclusion, EBV is identified as an independent poor prognostic factor for CHL patients. Therefore, examination of EBV association in CHL is recommended as routine pathologic practice especially in countries where EBV infection prevails.

A Multi-Component Model of Hodgkin's Lymphoma

Hodgkin’s lymphoma is an example for a tumor with an extremely tight interaction of tumor cells with cells from the tumor micro-environment. These so-called bystander cells are not inert but interact actively with the tumor cells. Some of these cells support tumor growth by delivery of co-stimulating and anti-apoptotic signals (“helper cells”). Other cells (“killer cells”) are involved in the anti-tumor immune response which is obviously not efficient enough for tumor elimination. The activity of both helper cells and killer cells is regulated by additional cells in the stroma (“regulatory cells”). The dynamic behavior of such multi-component systems is difficult to predict. In the present paper we propose a model that can be used for simulation of essential features of this system. In this model, tumor growth depends on (i) presence of few cancer stem cells, (ii) co-stimulation of cancer cells by the tumor stroma, (iii) activity of regulatory cells that suppress killer cells without suppression of helper cells. The success of cytotoxic/cytostatic therapy in this model varies depending on the therapy-related toxicity for each of the cell populations. The model also allows the analysis of immunotherapeutic interventions. Under certain conditions, paradox enhancement of tumor growth can occur after therapeutic intervention. The model might be useful for the design of new treatment strategies for Hodgkin’s lymphoma and other tumors with prominent tumor-stroma interaction.

Primary nodular lymphocyte-predominant Hodgkin lymphoma of uterine cervix mimicking leiomyoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) accounts for about 5% of all Hodgkin lymphomas and predominantly involves peripheral lymph nodes. Primary NLPHL of uterine cervix is very rare. Here, we report cervical NLPHL with CD21 expression in a 43-year-old woman, who presented with abnormal vaginal bleeding for 1 year.

Lymphomagenesis in Hodgkin lymphoma

Hodgkin lymphoma (HL) accounts for approximately 0.6% of all new cancer cases, 10% of all lymphomas in the USA, leading to an approximate 9000 new cases per year. It is very unique in that the neoplastic Hodgkin and Reed-Sternberg (HRS) cells of classical HL account for only 1% of the tumor tissue in most cases, with various inflammatory cells including B-cells, T-cells, mast cells, macrophages, eosinophils, neutrophils, and plasma cells comprising the tumor microenvironment. Recent research has identified germinal center B-cells to be the cellular origin of HRS cells. Various transcription factor dysregulation in these neoplastic cells that explains for the loss of B-cell phenotype as well as acquisition of survival and anti-apoptotic features of HRS cells has been identified. Aberrant activation of nuclear factor-kappa B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), and phosphoinositide 3-kinase (PI3K) pathways play a central role in HL pathogenesis. Both intrinsic genetic mechanisms as well as extrinsic signals have been identified to account for the constitutive activation of these pathways. The extrinsic factors that regulate the activation of transcription pathways in HRS cells have also been studied in detail. Cytokines and chemokines produced both by the HRS cells as well as cells of the microenvironment of HL work in an autocrine and/or paracrine manner to promote survival of HRS cells as well as providing mechanisms for immune escape from the body's antitumor immunity. The understanding of various mechanisms involved in the lymphomagenesis of HL including the importance of its microenvironment has gained much interest in the use of these microenvironmental features as prognostic markers as well as potential treatment targets. In this article, we will review the pathogenesis of HL starting with the cellular origin of neoplastic cells and the mechanisms supporting its pathogenesis, especially focusing on the microenvironment of HL and its associated cytokines.

Anaplastic large cell lymphomas: ALK positive, ALK negative, and primary cutaneous

Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.

A novel immunomodulatory molecularly targeted strategy for refractory Hodgkin's lymphoma

Although Hodgkin's lymphoma (HL) was one of the first human cancers to be cured by chemotherapy, no new agents other than brentuximab vedotin (Adcetris®, CD 30 directed antibody drug conjugate) have received US Food and Drug Administration (FDA) approval for HL since 1977. Subsets of young adult patients with HL continue to relapse, even after stem cell transplantation, warranting new approaches. Against this background, we report a dramatic response in a young patient with advanced HL refractory to the standard treatment who responded to the combination of a pan-histone deacetylase inhibitor (vorinostat, suberoylanilide hydroxamic acid, SAHA) and mammalian target of rapamycin (mTOR) inhibitor therapy (sirolimus,rapamume). In-depth immunohistochemical and morphoproteomic analyses of this exceptional responder to targeted therapy have yielded potential insights into the biology of advanced HL. The PI3K/AKT/mTOR pathway is a commonly activated pathway in multiple tumor types including HL. The patient was treated using therapy based on mechanistic in vitro data demonstrating that combined histone deacetylase (HDAC) and mTOR inhibition act together on this pathway, resulting in inhibition of reciprocal feedback networks, leading to better anti-proliferative activity. The in vivo response signature from this patient's tissue sample sheds light on immune dysregulation in HL. We describe the response signature achieved from targeting immune dysregulation in addition to targeting the key oncogenic PI3K/AKT/mTOR pathway. We also expand on the role of rapamycin analogs in oncology. This study supports a role for an immune-type pathogenesis that is amenable to immune modulating targeted therapy in refractory HL.

SIGNIFICANCE

We report an exceptional responder to molecularly targeted and immune modulator therapy in advanced Hodgkin's lymphoma. The morphoproteomic/morphometric findings in this "unusual responder" patient's relapsed HL that correlate best, as a response signature with the subsequent clinical remission following rapamycin (sirolimus) and vorinostat (SAHA) therapies, center on an immune dysregulation involving an imbalance between effector and functional T regulatory cells in addition to targeting the mTOR pathway. This underscores the need for an approach illustrated in our study--namely of focusing on pathogenetic mechanisms and combinatorial therapies that target both the pathogenesis and adaptive responses to contemplated therapies.

Expression of granzyme B sensitizes ALK+ ALCL tumour cells to apoptosis-inducing drugs

Background

The serine protease Granzyme B (GzB) is primarily expressed by cytotoxic T lymphocytes and natural killer cells, and functions in allowing these cells to induce apoptosis in virally-infected or transformed cells. Cancers of both lymphoid and non-lymphoid origin also express GzB, and in some cases this expression has been linked to pathogenesis or sensitizing tumour cells to cell death. For example, GzB expression in urothelial carcinoma was implicated in promoting tumour cell invasion, whereas its expression in nasal-type NK/T lymphomas was found to correlate with increased apoptosis. GzB expression is also a hallmark of the non-Hodgkin lymphoma, anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL). Given the fact that ALK+ ALCL exhibits high levels of apoptosis and is typically responsive to conventional chemotherapy, we examined whether GzB expression might play a role in sensitizing ALK+ ALCL tumour cells to apoptosis.

Methods

ALK+ ALCL cell lines stably expressing GzB or non-targeting (control) shRNA were generated and apoptosis was examined by anti-PARP western blotting and terminal deoxynucleotidyl transferase dUTP nick end labelling. Both spontaneous apoptosis and apoptosis in response to treatment with staurosporine or doxorubicin were investigated. In order to assess whether additional granzymes might be important in promoting cell death in ALK+ ALCL, we examined whether other human granzymes were expressed in ALK+ ALCL cell lines using reverse-transcriptase PCR and western blotting.

Results

Expression of several GzB shRNAs in multiple ALK+ ALCL cell lines resulted in a significant decrease in GzB levels and activity. While spontaneous apoptosis was similar in ALK+ ALCL cell lines expressing either GzB or control shRNA, GzB shRNA-expressing cells were less sensitive to staurosporine or doxorubicin-induced apoptosis as evidenced by reduced PARP cleavage and decreased DNA fragmentation. Furthermore, we found that GzB is the only granzyme that is expressed at significant levels in ALK+ ALCL cell lines.

Conclusions

Our findings are the first to demonstrate that GzB expression sensitizes ALK+ ALCL cell lines to drug-induced apoptosis. This suggests that GzB expression may be a factor contributing to the favourable response of this lymphoma to treatment.

Peripheral T-cell lymphomas of follicular T-helper cell derivation with Hodgkin/Reed-Sternberg cells of B-cell lineage: both EBV-positive and EBV-negative variants exist

Peripheral T-cell lymphomas (PTCLs) are functionally and morphologically complex. Epstein-Barr virus (EBV)-positive B cells have been reported in angioimmunoblastic T-cell lymphoma (AITL) and other PTCLs and may mimic Hodgkin/Reed-Sternberg (HRS) cells, but EBV-negative HRS-like B cells have not been described. We wished to assess the nature of the PTCL associated with HRS-like cells and to determine whether EBV-negative HRS-like cells may be seen. We identified 57 PTCL cases reported as containing HRS-like cells. These included 32 AITL, 19 PTCL, not otherwise specified (NOS), 3 PTCL-NOS, follicular variant, 1 PTCL-NOS, T-zone variant, and 2 adult T-cell leukemia/lymphoma cases. All patients were adults with a median age of 63 and presented with lymphadenopathy. The male:female ratio was 31:26 (1.2:1). Clonal TRG rearrangement was detected in 46/53 cases. Six of 38 cases had a concomitant clonal immunoglobulin gene rearrangement. In 52/57 cases the HRS cells were positive for EBV. Five cases, 3 classified as AITL and 2 as PTCL-NOS, follicular variant, contained HRS-like cells negative for EBV. All PTCLs with EBV-negative HRS cells had a T follicular helper cell immunophenotype. The neoplastic T cells expressed CD3, CD4, and PD-1 and formed rosettes around the HRS-like cells. The HRS-like cells were positive for CD20 (variable intensity), PAX5, CD30, and CD15 (4/5). We conclude that both EBV-positive and EBV-negative HRS-like B cells may occur in the background of PTCL; caution is needed to avoid misdiagnosis as classical Hodgkin lymphoma. The close interaction between the HRS-like cells and the rosetting PD-1-positive T cells suggests a possible pathogenetic role in this phenomenon and provides new insights into the abnormal B-cell proliferations that occur in the context of TFH malignancies.

Classical Hodgkin lymphoma, lymphocyte depleted type: clinicopathological analysis and prognostic comparison with other types of classical Hodgkin lymphoma

The lymphocyte-depleted type (LD) is a morphological subtype of classical Hodgkin lymphoma (CHL), but its rarity and heterogeneous morphological character makes a definite clinicopathological identification difficult. To characterize this disease, LD cases were compared with other types of CHL. From 1982 to 2006, we collected 310 CHL cases. Among them, 29 cases were diagnosed as LD. We could additionally analyze clinical data of 157 CHL cases (including 28 LD cases) and the immunophenotype of 150 CHL cases (including 28 LD cases). We compared clinicopathological data between LD cases and other types of CHL cases and determined prognostic factors by univariate and multivariate analysis. LD showed a more progressive disease stage (stage 3/4, 64%) than other types of CHL (stage 3/4, 30%; P<0.001), more frequent B symptoms (89% vs. 40%; P<0.001) and extranodal invasion (50% vs. 11%; P<0.001), older age (median: 66 vs. 33; P<0.001), higher serum soluble interleukin 2 receptor levels (median: 8240U/ml vs. 1705U/ml; P<0.001), and much poorer prognosis regardless of the international prognostic score (IPS) (five-year overall survival: 29% vs. 86%; P<0.001). The morphological subtype of LD represented an independent prognostic factor as did age and IPS by multivariate analysis. Immunohistochemistry showed that the characteristics of Hodgkin and Reed-Sternberg (HRS) cells of LD are basically not different from those of other types of CHL in terms of CD30, CD15, and chemokine receptors, except for high-level EB-virus infection (72% vs. 41%; P=0.002). LD should be distinguished from other types of classical Hodgkin lymphoma because of its definitive clinicopathological characters.

Aberrant T-cell antigen expression in classical Hodgkin lymphoma is associated with decreased event-free survival and overall survival

Hodgkin/Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL) rarely express T-cell-associated antigens (TCA), but the clinical significance of this finding is uncertain. Fifty cHLs expressing any TCA on the HRS cells (TCA-cHL) were identified in two cohorts (National Cancer Institute, n = 38; Basel, n = 12). Diagnostic pathology data were examined in all cases with additional T-cell receptor γ rearrangements (TRG@) polymerase chain reaction (PCR) in a subset of cases. The outcome data were compared with a cohort of cHLs negative for TCA (n = 272). Primary end points examined were event-free survival (EFS) and overall survival (OS). The median age in the TCA-cHL group was 40 years (range, 10-85 years). Seventy percent presented in low stage (stage I/II) at presentation with nodular sclerosis (NS) histology predominating in 80% of cases. Among the TCA, CD4 and CD2 were most commonly expressed, seen in 80.4% and 77.4% of cases, respectively. TRG@ PCR was negative for clonal rearrangements in 29 of 31 cases. During a median follow up of 113 months, TCA expression predicted shorter OS (adjusted hazard ratio [HRadj] = 3.32 [95% confidence interval (CI): 1.61, 6.84]; P = .001) and EFS (HRadj = 2.55 [95% CI: 1.45, 4.49]; P = .001). TCA-cHL often display NS histology, lack T-cell genotype, and are independently associated with significantly shorter OS and EFS compared with TCA-negative cHLs.

CD137 is expressed in follicular dendritic cell tumors and in classical Hodgkin and T-cell lymphomas: diagnostic and therapeutic implications

CD137 (also known as 4-1BB and TNFRSF9) is a member of the tumor necrosis factor receptor superfamily. Originally identified as a costimulatory molecule expressed by activated T cells and NK cells, CD137 is also expressed by follicular dendritic cells, monocytes, mast cells, granulocytes, and endothelial cells. Anti-CD137 immunotherapy has recently shown promise as a treatment for solid tumors and lymphoid malignancies in preclinical models. We defined the expression of CD137 protein in both normal and neoplastic hematolymphoid tissue. CD137 protein is expressed by follicular dendritic cells in the germinal center and scattered paracortical T cells, but not by normal germinal-center B cells, bone marrow progenitor cells, or maturing thymocytes. CD137 protein is expressed by a select group of hematolymphoid tumors, including classical Hodgkin lymphoma, T-cell and NK/T-cell lymphomas, and follicular dendritic cells neoplasms. CD137 is a novel diagnostic marker of these tumors and suggests a possible target for tumor-directed antibody therapy.

PD-1-expressing tumor-infiltrating T cells are a favorable prognostic biomarker in HPV-associated head and neck cancer

Head and neck cancers positive for human papillomavirus (HPV) have a more favorable clinical outcome than HPV-negative cancers, but it is unknown why this is the case. We hypothesized that prognosis was affected by intrinsic features of HPV-infected tumor cells or differences in host immune response. In this study, we focused on a comparison of regulatory Foxp3(+) T cells and programmed death-1 (PD-1)(+) T cells in the microenvironment of tumors that were positive or negative for HPV, in two groups that were matched for various clinical and biologic parameters. HPV-positive head and neck cancers were more heavily infiltrated by regulatory T cells and PD-1(+) T cells and the levels of PD-1(+) cells were positively correlated with a favorable clinical outcome. In explaining this paradoxical result, we showed that these PD-1(+) T cells expressed activation markers and were functional after blockade of the PD-1-PD-L1 axis in vitro. Approximately 50% of PD-1(+) tumor-infiltrating T cells lacked Tim-3 expression and may indeed represent activated T cells. In mice, administration of a cancer vaccine increased PD-1 on T cells with concomitant tumor regression. In this setting, PD-1 blockade synergized with vaccine in eliciting antitumor efficacy. Our findings prompt a need to revisit the significance of PD-1-infiltrating T cells in cancer, where we suggest that PD-1 detection may reflect a previous immune response against tumors that might be reactivated by PD-1/PD-L1 blockade.

Plasmablastic lymphoma of the elderly: a clinicopathological comparison with age-related Epstein-Barr virus-associated B cell lymphoproliferative disorder

AIMS

Plasmablastic lymphoma (PBL) is an aggressive lymphoma with a terminally differentiated B cell phenotype; half of patients with this disease have Epstein-Barr virus (EBV) infection. The majority of PBL cases are associated with human immunodeficiency virus (HIV) infection, while the remaining HIV-negative cases were accompanied by other immunodeficiency conditions or immunosenescence in the elderly.

METHODS AND RESULTS

To characterize HIV-negative PBL of the elderly (PBL-E), we compared the clinicopathological characteristics of 10 cases of PBL-E and 124 cases with age-related EBV-associated B cell lymphoproliferative disorder (AR-EBVLPD). The 10 PBL-E (eight men, two women; median age: 68 years) were associated with a more indolent clinical behaviour and a better overall survival than AR-EBVLPD. Extranodal involvement was higher in PBL-E (50%) than AR-EBVLPD; notably, the nasal cavity was affected most frequently in PBL-E (60%). Immunoglobulin heavy chain/(IGH)/MYC translocation was detected in half of the PBL-E cases.

CONCLUSIONS

PBL-E shares some clinical features with AR-EBVLPD, such as HIV negativity, old age, and EBV infection, no known immunosuppressive condition but there are some differences such as a higher ratio of extranodal involvement and better prognosis. PBL-E is a newly recognized condition and should be distinguished from HIV-positive PBL, sharing features with AR-EBVLPD in particular, immunosenescence of the elderly.

Gene expression profiling of microdissected Hodgkin Reed-Sternberg cells correlates with treatment outcome in classical Hodgkin lymphoma

In classical Hodgkin lymphoma (CHL), 20%-30% of patients experience relapse or progressive disease after initial treatment. The pathogenesis and biology of treatment failure are still poorly understood, in part because the molecular phenotype of the rare malignant Hodgkin Reed-Sternberg (HRS) cells is difficult to study. Here we examined microdissected HRS cells from 29 CHL patients and 5 CHL-derived cell lines by gene expression profiling. We found significant overlap of HL-specific gene expression in primary HRS cells and HL cell lines, but also differences, including surface receptor signaling pathways. Using integrative analysis tools, we identified target genes with expression levels that significantly correlated with genomic copy-number changes in primary HRS cells. Furthermore, we found a macrophage-like signature in HRS cells that significantly correlated with treatment failure. CSF1R is a representative of this signature, and its expression was significantly associated with progression-free and overall survival in an independent set of 132 patients assessed by mRNA in situ hybridization. A combined score of CSF1R in situ hybridization and CD68 immunohistochemistry was an independent predictor for progression-free survival in multivariate analysis. In summary, our data reveal novel insights into the pathobiology of treatment failure and suggest CSF1R as a drug target of at-risk CHL.

The ratio of the absolute lymphocyte count to the absolute monocyte count is associated with prognosis in Hodgkin's lymphoma: correlation with tumor-associated macrophages

BACKGROUND

Although most patients with classical Hodgkin's lymphoma (cHL) have a long survival duration, the current risk stratification is imperfect. A recent study suggested a prognostic role for the peripheral blood absolute lymphocyte count/absolute monocyte count (ALC/AMC) ratio at diagnosis in cHL. It is intriguing to investigate the significance of the ALC/AMC ratio in relation to tumor-associated macrophages (TAMs), yet another prognostic factor for cHL.

METHODS

We examined the prognostic impact of the ALC, AMC, and ALC/AMC ratio in 312 cHL patients (median age, 37 years) using receiver operating characteristic curve analysis for optimal cutoff values, and compared these with TAM content.

RESULTS

The median follow-up was 65 months (range, 0.1-245 months). On univariate analysis, a low ALC/AMC ratio (<2.9) was correlated with a poorer overall survival (OS) outcome. A subgroup analysis of patients with limited-stage disease showed that the ALC/AMC ratio was significantly correlated with the OS time. Multivariate analysis showed the ALC/AMC ratio to be an independent prognostic factor for OS outcome. A Spearman correlation test of TAM content showed a negative correlation with the ALC/AMC ratio and a positive correlation with the peripheral blood macrophage percentage.

CONCLUSIONS

This study suggests that the ALC/AMC ratio may be a simple, inexpensive, and independent prognostic factor for OS outcome in patients with cHL and may have a role in the stratification of cHL patients in addition to the International Prognostic Score and TAM content.

Histone deacetylase inhibition restores cisplatin sensitivity of Hodgkin's lymphoma cells

Increasing evidence suggest that epigenetic mechanisms (e.g. histone modification by histone deacetylases) play a major role in the pathogenesis of Hodgkin's lymphoma (HL). We treated HL cell lines with the histone deacetylase inhibitor vorinostat and investigated the gene expression profile of these cells by using DNA microarrays. Vorinostat inhibited cell proliferation and induced chances in the gene expression profile of HL cells, including down regulation of interleukin-26 and CD30. Vorinostat also increased sensitivity for cisplatin. Our data suggest that the combination of vorinostat and chemotherapy might be an interesting option for patients with chemoresistant HL.