Epstein-Barr virus infection, drug resistance and prognosis in Korean T- and NK-cell lymphomas

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

What Effect Does Epstein-Barr Virus Have on Extranodal Natural Killer/T-Cell Lymphoma Prognosis? A Review of 153 Reported Cases

The primary aim of this review is to identify the relationship between Epstein-Barr virus (EBV) and prognosis in extranodal natural killer/T-cell lymphoma (ENKTL). Additionally, a literature review of ENKTL was carried out. The investigators designed and implemented a 21-year literature review using the online databases PubMed and Google Scholar. The total number of cases analyzed was 153 (64 case reports; one comparative study; one systematic review). Information related to ENKTL from July 1999 to February 2021 was included in the study. Study variables included: patient demographics, tumor classification, screening modalities, tumor characteristics, symptomatology, treatment, and prognosis. The average age at diagnosis was 50.9 years (range: 4-90 years). Patients of Asian ethnicity were most commonly affected, and there was a 1.6:1 male to female ratio. ENKTL was most frequently detected in the head and neck region, and 53.1% of cases metastasized. Of all head and neck cases, the nose was the most affected location. Immunohistochemistry positivity included: EBV (32.0%), CD2 (96.6%), CD3ϵ (81.7%), CD43 (91.7%), CD56 (86.4%), Granzyme (97.1%), Perforin (90.9%), TIA-1 (97.8%), p53 (33.3%). The most frequently employed single treatment modality was chemotherapy alone, and 34.2% of patients expired within five years of diagnosis. The average follow-up period was 16.51 months (range: 0.25-66 months). EBV was significantly associated with metastatic ENKTL (χ² = 4.36; CV = 3.84; p = 0.037). We found no association between EBV and ENKTL prognosis (χ² = 17.2; CV = 21.0; p = 0.14).

Extranodal NK/T-cell lymphoma, nasal type without evidence of EBV infection

Extranodal natural killer/T cell lymphoma-nasal type (EN-NK/T-NT) is extremely rare in Western countries; however, it is the most common subtype of peripheral T cell lymphoma in China. Despite this, there are a limited number of clinicopathological research studies on Epstein-Barr virus (EBV)-negative EN-NK/T-NTs. EBV-negative EN-NK/T-NT is a rare disease type, which has not been fully investigated. If other diagnostic criteria are met, such as the lesions being located predominantly in the upper aerodigestive tract, the presence of angiocentricity or angioinvasion, necrosis and expression of NK/T-cell phenotype, EN-NK/T-NT may be diagnosed, even if EBV is negative. In the present study, 99 cases of EN-NK/T-NTs were analyzed retrospectively, among which seven cases were EBV-negative EN-NK/T-NTs and selected for further investigation. In addition, the present study reviewed previously published research into EN-NK/T-NT, highlighting that EBV-negative EN-NK/T-NT is rare and that its geographical distribution is mainly in countries in Asia, Central America and South America. Patients with EBV-negative EN-NK/T-NT were all of Chinese ethnicity, with a median age of 32 years and primarily female. Furthermore, these patients shared similar clinicopathological characteristics (such as the tumor occurring mainly in the upper aerodigestive tract, the presence of vascular destruction, necrosis and cytotoxic phenotypes) to patients with EBV-positive EN-NK/T-NT. Immunohistochemistry and molecular analysis results indicated that tumor cells were primarily of NK or cytotoxic T origin; however, EBV-encoded small RNAs were not detected in any of these cases. Among the immunochemistry markers, T-bet was statistical significantly different between EBV-positive and -negative cases. Fluorescence in situ hybridization was also performed in two EBV-negative cases, including one case with a co-deletion of 6q21 and PR/SET domain 1 genes. There was only available follow-up data in 3/5 patients who survived for 37–113 months (median, 40 months). As EN-NK/T-NT can be diagnosed, even when EBV is negative, awareness of this subtype may prevent misdiagnosis or delayed diagnosis.

Epstein-Barr virus-negative extranodal "true" natural killer-cell lymphoma harbouring a KDM6A mutation

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an extranodal aggressive T or NK-cell lymphoma that is characteristically associated with Epstein-Barr virus (EBV) infection and cytotoxic tissue-destructive features. Although ENKTL is described as a distinct entity according to the 2008 WHO classification, a considerable complexity is associated with the differential diagnosis of other T-cell lymphomas with respect to tumour cell origins, locations, and the presence of EBV infection, as well as molecular and cytogenetic abnormalities. Here, we report a rare case of EBV-negative ENKTL, where the absence of EBV in the true NK-lineage cells was confirmed by extensive phenotypic and genotypic analyses. Furthermore, using the next-generation sequencing approach, we identified mutations in the tumour suppressor genes KDM6A and TP53. The clinicopathological characteristics were almost similar to those of EBV-positive ENKTL, except for the absence of EBV and histologically apparent angioinvasiveness. This is the first reported ENKTL case with mutations in the KDM6A gene. KDM6A is one of the histone-modifying genes that are mutated in many human diseases including haematological cancers. Epigenetic regulation of gene expression has recently been demonstrated in ENKTL, and a similar pathway is thought to play an oncogenic role in EBV-negative ENKTL. Our report shows the extent of comprehensive examination required before making a definitive diagnosis for NK- and T-cell neoplasms and broadens the therapeutic options for potential targets.

The significance of combining radiotherapy with chemotherapy for early stage extranodal natural killer/T-cell lymphoma, nasal type: a systematic review and meta-analysis

Abstract Radiotherapy is regarded as a primary treatment for early stage extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL). However, whether combined modality treatment (CMT) comprising radiotherapy and chemotherapy is necessary remains controversial. A systematic review and meta-analysis of studies was performed to evaluate the significance of combining radiotherapy with chemotherapy for early stage ENKTL. Comparison of CMT and radiotherapy alone (RT) showed no significant difference by the measurement of complete response (CR) (odds ratio [OR] 1.07; 95% confidence interval [CI] 0.73-1.58; p = 0.73), 5-year overall survival rate (OS) (HR 0.73; 95% CI 0.45-1.19; p = 0.21) and progression-free survival rate (PFS) (HR 0.76; 95% CI 0.50-1.17; p = 0.21). Additional chemotherapy did not decrease systemic failure (OR 1.52; 95% CI 0.97-2.40; p = 0.07), as well as locoregional failure (OR 0.94; 95% CI 0.52-1.73; p = 0.85). The results may support the assertion that the combination of radiotherapy with chemotherapy cannot improve treatment outcomes, but rather it increases adverse effects and financial costs. However, these results should be interpreted with caution.

Impact of dexamethasone, etoposide, ifosfamide and carboplatin as concurrent chemoradiotherapy agents for nasal natural killer/T-cell lymphoma

The nasal type of extranodal natural killer (NK)/T-cell lymphoma (NKTCL) is a rare aggressive lymphoma with poor prognosis. The reported 5-year overall survival for patients with localized nasal NKTCL treated with cyclophosphamide, hydroxydaunorubicin, oncovin and prednisone (CHOP) is <50%. Dexamethasone, etoposide, ifosfamide and carboplatin (DeVIC) chemotherapy was designed as a salvage chemotherapeutic regimen for aggressive lymphoma, comprising multidrug resistance (MDR) non-related agents and etoposide, which is considered to be effective against nasal NKTCL. An experimental chemoradiotherapy (CRT) is currently being designed using DeVIC as the concurrent chemotherapeutic regimen for nasal NKTCL. The aim of this study was to examine the initial outcome of this treatment and evaluate its effectiveness and feasibility. Six patients (age range, 29–82 years; median age, 68 years) were treated with CRT using DeVIC between April, 2004 and February, 2010. The median follow-up was 56 months (range, 11–80 months). All patients were administered 3–6 cycles of full-dose DeVIC regimen. The chemotherapy was administered concurrently with radiotherapy (RT) and was repeated every 3 weeks. RT was performed using 4-MV X-ray and the prescription dose was 46–50 Gy/23–25 fx (median, 50 Gy). After treatment, all patients were followed up at our hospital. A complete remission was achieved in 5 patients (83%) at 1 month after treatment. The 5-year overall survival and disease-free survival rates were 100%. No severe adverse effect (grade ≥3) was reported. In conclusion, the initial results of the experimental CRT with DeVIC for this type of aggressive lymphoma were very encouraging. Further investigation is required on concurrent CRT with 50 Gy/25 fx and 3 cycles of DeVIC comprising non-MDR agents and etoposide for nasal NKTCL.

Prognostic significance of EBV latent membrane protein 1 expression in lymphomas: evidence from 15 studies

Background

Epstein-Barr virus (EBV) infection has been associated with lymphoma development. EBV latent membrane protein 1 (LMP1) is essential for EBV-mediated transformation and progression of different human cells, including lymphocytes. This meta-analysis investigated LMP1 expression with prognosis of patients with lymphoma.

Methods

The electronic databases of PubMed, Embase, and Chinese Biomedicine Databases were searched. There were 15 published studies available for a random effects model analysis. Quality assessment was performed using the Newcastle-Ottawa Quality Assessment Scale for cohort studies. A funnel plot was used to investigate publication bias, and sources of heterogeneity were identified by meta-regression analysis. The combined hazard ratios (HR) and their corresponding 95% confidence intervals of LMP1 expression were calculated by comparison to the overall survival.

Results

Overall, there was no statistical significance found between LMP1 expression and survival of lymphoma patients (HR 1.25 [95% CI, 0.92–1.68]). In subgroup analyses, LMP1 expression was associated with survival in patients with non-Hodgkin lymphoma (NHL) (HR  = 1.84, 95% CI: 1.02–3.34), but not with survival of patients with Hodgkin disease (HD) (HR  =  1.03, 95% CI: 0.74–1.44). In addition, significant heterogeneity was present and the meta-regression revealed that the outcome of analysis was mainly influenced by the cutoff value.

Conclusions

This meta-analysis demonstrated that LMP1 expression appears to be an unfavorable prognostic factor for overall survival of NHL patients. The data suggested that EBV infection and LMP1 expression may be an important factor for NHL development or progression.

Primary cutaneous Epstein-Barr virus-associated T-cell lymphoproliferative disorder-2 cases with unusual, prolonged clinical course

Hydroa vacciniforme-like lymphoma and extranodal-type natural killer (NK)/T-cell lymphoma are prototypes of Epstein-Barr virus (EBV)-associated cutaneous T- or NK-cell lymphomas. Hydroa vacciniforme-like lymphoma with systemic spread and extranodal-type NK/T-cell lymphoma are characterized by aggressive clinical course. We describe 2 patients with primary cutaneous EBV-associated T-cell lymphomas who did not satisfy the criteria for well-defined entities and showed unusual, prolonged clinical course. They presented with skin ulcerations and mass lesions confined to the extremities without systemic involvement. Skin biopsies demonstrated dense superficial and deep perivascular and periappendageal lymphoid infiltrates expressing CD3 and CD8, but not CD56. The EBV genomes were found within the tumor cells, and monoclonal T-cell receptor gene rearrangement was present. We suggest that these cases represent a peculiar subtype of EBV+ cutaneous T-cell lymphoma, with a tendency to localize in the skin of the extremities and has an indolent clinical course.

Risk stratification in extranodal natural killer/T-cell lymphoma

Extranodal natural killer/T-cell lymphoma (ENKL), a subtype of natural killer/T-cell malignancies, is a rare subset of lymphomas with significant biological and clinical heterogeneity. The prognosis of ENKL is variable and therapeutic approaches are not well established. The optimal dose, combination, and sequence of radiotherapy and chemotherapy are evolving, as is the role of stem cell transplantation. Radiotherapy is an essential component of therapy for early-stage disease. The clinical course of advanced disease is highly aggressive, with frequent chemotherapy resistance and a poor prognosis. For relapsed disease, asparaginase-based regimens have provided encouraging results and are currently under investigation in the frontline setting. Our article discusses the key aspects of biology, pathogenesis and clinical presentation that contribute to the heterogeneity, and proposes a stratified approach to the treatment of ENKL based on clinical, pathologic and biologic risk factors. Although considerable advances have been made in our understanding of the biology and prognosis of this lymphoma, it remains critical that all patients with a diagnosis of ENKL are enrolled and treated in clinical trials so that optimal therapies can be identified.

Extranodal natural killer/T-cell lymphoma: current concepts in biology and treatment

Natural killer/T-cell (NK/T) lymphomas represent a group of rare tumors of NK and NK-T cells. The World Health Organization classifies NK-cell tumors into three types, extranodal NK/T-cell lymphomas (ENKL, nasal and non-nasal), NK-cell leukemias, and a blastic variant (CD4-positive, CD56-positive hematodermic neoplasms). We focus our review to the current concepts in biology and treatment of ENKL. Though considerable advances have been made in our understanding of NK-cell biology, malignant transformation including the role of Epstein-Barr virus, and prognosis, the rare nature of ENKL and its heterogeneity limit the ability to standardize therapy. Radiotherapy is fundamental to treatment of early-stage disease with a role for chemoradiotherapy among high-risk patients. The clinical course of advanced disease is highly aggressive with frequent chemotherapy resistance and a poor prognosis. Therapeutic approaches to advanced-stage or relapsed and refractory disease, including the appropriate sequence of chemotherapy, combined modality therapy, and stem cell transplantation is not well-established. International and multicenter clinical trials are needed for this rare and aggressive disease.

A randomized phase II study of CEOP with or without semustine as induction chemotherapy in patients with stage IE/IIE extranodal NK/T-cell lymphoma, nasal type in the upper aerodigestive tract

PURPOSE

In this randomized phase II study, we evaluated the efficacy of semustine added to CEOP regimen as induction chemotherapy in patients with stage I(E)/II(E) extranodal NK/T-cell lymphoma, nasal type in the upper aerodigestive tract.

PATIENTS AND METHODS

Seventy-five eligible patients were randomized to receive either CEOP or CEOP plus semustine followed by involved-field radiotherapy.

RESULTS

The overall response rate of induction chemotherapy was 57.9% in CEOP arm compared with 62.2% in CEOP plus semustine arm (P=0.71). With a median follow-up of 30.1 months, 2-year overall survival was 73.3% and 62.2%, respectively (P=0.37). Toxicities in both arms were comparable and manageable. Through univariate and multivariate analysis, PS of 2, Stage II(E) and elevated LDH level were identified to be adverse prognostic factors. A new prognostic index categorized three groups of patients (low risk, no adverse factors; intermediate risk, one factor; and high risk, 2 or 3 factors) with highly significant difference of prognosis. Two-year overall survival was 87.5%, 60.6% and 30%, respectively (P=0.0002).

CONCLUSIONS

The addition of semustine to CEOP regimen was not associated with improved efficacy. More effective treatment needs to be explored in patients with intermediate or high risk.

Low frequency of Epstein Barr virus association and high frequency of p53 overexpression in an Argentinean pediatric T-cell lymphoma series

T-cell non-Hodgkin's lymphomas (NHLs) represent 10% to 15% of all diagnosed lymphomas in Western countries. Various geographic frequencies of T-cell NHL have been documented, in part reflecting increased exposure to pathogenic factors such as Epstein-Barr virus (EBV). Our aims were to assess EBV and p53 expression in Argentine pediatric T-cell lymphoma and to correlate them with patients' survival. Epstein-Barr encoded RNAs (EBERs) in situ hybridization and LMP1 and p53 immunohistochemical staining were performed on formalin-fixed paraffin-embedded lymph node biopsies from 25 pediatric T-lymphoma patients. In 17 of 25 samples good-quality DNA was obtained, and EBER polymerase chain reaction was assessed to confirm in situ hybridization and immunohistochemical results. Epstein-Barr virus expression was found in 8.0% of cases. p53-positive staining was distributed in 92% of pediatric cases. Kaplan-Meier survival analysis showed that neither EBV nor p53 expression was statistically significantly associated with event-free survival. Our data showed a low frequency of EBV association with pediatric T-cell lymphoma. It seems that p53 plays an important role in proliferation in our studied population, since it is overexpressed in 92% of T-cell lymphoma cases.

Immunohistochemical expression of multidrug resistance proteins in mature T/NK-cell lymphomas

Multidrug resistance (MDR) is defined as resistance of tumor cells to a wide spectrum of structurally and functionally unrelated drugs. One of the most important mechanisms in mediating MDR is that involving cellular drug efflux transporters. Drug resistance is a common and formidable obstacle to therapy in mature T/NK-cell lymphomas and the MDR phenotype is thought to be one of the contributing mechanisms. In this study we assessed the immunohistochemical expression of P-gp (P-glycoprotein), MRP-1 (multidrug resistance associated protein 1), BCRP (breast cancer resistance protein) and LRP (lung resistance protein) in 45 mature T/NK-cell lymphomas diagnosed at our hospital. We detected P-gp expression in 31% (13/42), MRP-1 expression in 74% (31/42), BCRP in 78% (32/41) and LRP in 59% (26/44) of the cases. These findings show that our T/NK-cell lymphoma cases display high frequency of MDR protein expression.

Immunohistochemical expression and clinical significance of P-glycoprotein in previously untreated extranodal NK/T-cell lymphoma, nasal type

Overexpression of P-glycoprotein (P-gp) has been identified by a variety of methods in NK cells and NK malignancies. The aim of this study was to determine the clinical significance of P-gp in previously untreated extranodal NK/T-cell lymphoma, nasal type. Tumor specimens from 30 patients initially treated with CHOP or CHOP-based chemotherapy were examined by immunohistochemistry using JSB-1, a monoclonal antibody recognizing the intracellular epitope of P-gp molecule. Twenty cases (67%) were positive for P-gp expression. The complete response rate achieved in P-gp positive patients was significantly lower than in P-gp negative ones (20% vs. 60%, P = 0.045). With a median follow-up of 25 months, the 2-year progression-free survival (PFS) and overall survival (OS) rates for all patients were 66 and 69%, respectively. Compared with both PFS and OS rates of P-gp positive patients, those of P-gp negative patients showed a trend of benefit that did not reach statistical significance for borderline P values (PFS: 90% vs. 54%, P = 0.1057; OS: 90% vs. 61%, P = 0.2028). Our results suggest that P-gp expression is related with poor treatment outcomes of extranodal NK/T-cell lymphoma, nasal type.

Allogeneic hematopoietic stem cell transplantation for Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disease in Japan

Epstein-Barr virus (EBV)-associated T/NK-cell lymphoproliferative disease (LPD) has been linked to several different disorders. Its prognosis is generally poor and a treatment strategy has yet to be established. There are reports, however, that hematopoietic stem cell transplantation (HSCT) can cure this disease. To clarify the current situation regarding allogeneic hematopoietic stem cell transplantation (allo-HSCT) for EBV-associated T/NK-LPD, a nationwide survey was performed in Japan. Data for 74 patients were collected. There were 42 cases of chronic active EBV infection (CAEBV), 10 cases of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), and 22 cases of EBV-associated lymphoma/leukemia (EBV-lymphoma/leukemia). Of those with CAEBV, 54% had the EBV-infected T-cell type and 59% with EBV-lymphoma/leukemia had the EBV-infected NK-cell type. Most patients with EBV-HLH and EBV-lymphoma/leukemia received allo-HSCT within 1 year after onset compared to only 14% of patients with CAEBV. The event-free survival (EFS) rate following allo-HSCT was 0.561 +/- 0.086 for CAEBV, 0.614 +/- 0.186 for EBV-HLH, and 0.309 +/- 0.107 for EBV-lymphoma/leukemia. The EFS of allo-HSCT with conventional conditioning was 0.488 +/- 0.074 and with reduced-intensity conditioning was 0.563 +/- 0.124. Thus, in a substantial number of cases, EBV-associated T/NK-LPD can be cured by either allogeneic conventional stem cell transplantation or reduced-intensity stem cell transplantation.

Dithiocarbamates and viral IL-10 collaborate in the immortalization and evasion of immune response in EBV-infected human B lymphocytes

Epstein-Barr virus (EBV) is implicated in the development of a number of human malignancies including several subtypes of non-Hodgkin lymphoma (NHL) [G. Pallesen, S.J. Hamilton-Dutoit, X. Zhou, The association of Epstein-Barr virus (EBV) with T cell lymphoproliferations and Hodgkin's disease: two new developments in the EBV Field, Adv. Cancer Res. 62 (1993) 179-239]. Lymphoproliferative disease and NHL occurring in severely immunosuppressed individuals almost always involve EBV and have been extensively studied and modeled in vitro. EBV has also been causally associated with some cases of NHL occurring in otherwise immunocompetent individuals. However, a direct role for EBV in the pathogenesis of neoplasms developing in the presence of an otherwise competent immune system has not been established. We investigated potential interactions between dithiocarbamates (DTC), an important class of thiono-sulfur compounds, and EBV leading to immortalization of human B lymphocytes and evasion of cell-mediated immune response in culture. Primary lymphocyte cultures employing wild-type and recombinant EBV mutants were used to assess the respective roles of DTC and viral genes in lymphocyte transformation and survival. Pretreatment of EBV-infected human B lymphocytes with DTC directly enhanced transformation in the absence of T cells (5 nM) and independently increased survival of transformed cells in the presence of competent autologous T cells (10 nM). Both DTC-induced transformation and immortalization of EBV-infected B lymphocytes were dependent on the expression of viral IL-10. These results provide a biological basis for studying collaborations between chemical and virus that alter lymphocyte biology, and provide a rationale for further molecular epidemiology studies to better understand the potential influence of these interactions on the development of NHL and perhaps other viral-associated malignancies.

Pathogenesis and mechanism of disease progression from hemophagocytic lymphohistiocytosis to Epstein-Barr virus-associated T-cell lymphoma: nuclear factor-kappa B pathway as a potential therapeutic target

Epstein-Barr virus (EBV) can infect T lymphocytes and manifests as hemophagocytic lymphohistiocytosis (HLH), a distinct entity of hemophagocytic syndrome (HPS) characterized by fever, hepatosplenomegaly, cytopenia, hypercytokinemia, and systemic macrophage activation with hemophagocytosis. In a substantial percentage of HLH patients, the disease may relapse or progress to T-cell lymphoma in months to years. In the present review, the authors summarize the previous studies on the pathogenesis of HLH and the potential mechanism for the progression of disease from HLH to T-cell lymphoma. The infection of T cells by EBV could activate T cells to secrete proinflammatory cytokines, particularly tumor necrosis factor-alpha (TNF-alpha), which subsequently activate macrophages. EBV latent membrane protein-1 (LMP-1) is the viral product responsible for the activation of the TNF receptor (TNFR) associated factors/nuclear factor-kappaB (NF-kappaB)/ERK pathway to enhance cytokine secretion mediated through the suppression of the SAP/SH2D1A gene. The activation of NF-kappaB will confer resistance to TNF-alpha-induced apoptosis on EBV-infected T cells through the down-regulation of TNFR-1. Consistent with in vitro observations, EBV-associated T or natural killer/T-cell lymphoma showed constitutive activation of NF-kappaB, explaining its drug resistance, hypercytokinemia, and poor prognosis. Therefore, similar to other inflammation-associated cancers, HLH provides a unique model to study the mechanism of disease progression from a benign virus-infected disorder (HLH) to T-cell lymphoma. Inhibition of the NF-kappaB signal pathway should provide a potential target for the treatment of HLH and EBV-associated T-cell lymphoma.

Extranodal NK/T-cell lymphoma, nasal type

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL), previously known as lethal midline granuloma is a distinct clinico-pathological entity associated with Epstein-Barr virus that typically causes destruction of the midface, palatal and orbital walls. In addition, ENKTCL can involve the skin, soft tissue, testes, gastrointestinal and upper respiratory tract. ENKTCL neoplastic cells express some T-cell associated antigens, most commonly CD2 and cytoplasmic CD3epsilon and, in favour of an NK-cell origin, CD56. Early stage disease may respond to radiotherapy alone, however late stage disease does not respond well to any available therapies. Overall, patients with ENKTCL have a cumulative probability of survival at 5 years ranging from 37.9% to 45.3%.

Immunohistochemical expression of multidrug resistance proteins as a predictor of poor response to chemotherapy and prognosis in patients with nodal diffuse large B-cell lymphoma

BACKGROUND/AIMS

The aim of this study was to determine whether expression of P-glycoprotein (P-gp), multidrug-resistance-related protein 1 (MRP1), and lung resistance protein (LRP) was related to the response to induction chemotherapy and prognosis in untreated diffuse large B-cell lymphoma (DLBCL).

METHODS

We assessed immunohistochemical expression of P-gp, MRP1 and LRP, using formalin-fixed and paraffin-embedded specimens of lymph node in 41 patients with DLBCL. Association between expression of these three proteins and their impact on clinical outcome and prognosis was statistically evaluated.

RESULTS

P-gp was positive in 37% of subjects, MRP1 in 63%, and LRP in 68%. The complete remission rates achieved in the group expressing these multidrug resistance (MDR) proteins was significantly lower than in the group not expressing them (20 versus 58%; p = 0.025 in P-gp, 23 versus 80%; p < 0.001 in MRP1 and 32 versus 69%, p = 0.043 in LRP, respectively). Furthermore, the patients expressing LRP had a shorter overall survival rate than those that did not (median of 26 months versus median not reached; p = 0.013).

CONCLUSIONS

These findings suggest that the three MDR proteins are important predictive factors for the clinical outcome and prognosis in patients with DLBCL.

Clinical relevance of three subtypes of primary sinonasal lymphoma characterized by immunophenotypic analysis

BACKGROUND

The purpose of this study was to investigate the clinical relevance of subtypes categorized by immunophenotypic analysis in primary sinonasal lymphomas.

METHODS

Eighty patients with localized non-Hodgkin's lymphoma involving the nasal cavity and/or paranasal sinuses were divided into three subtypes on the basis of their immunohistochemical findings: (A) B-cell lymphoma (n = 19), (B) T-cell lymphoma (n = 27), and (C) natural killer (NK)/T-cell lymphoma (n = 34). The clinicopathologic profiles, immunophenotypic data, patterns of treatment failure, and survival data among the three patient groups were retrospectively compared.

RESULTS

The nasal cavity was the predominant site of involvement in T-cell and NK/T-cell lymphoma, whereas sinus involvement without nasal disease was common in B-cell lymphoma. Systemic B symptoms were frequently observed in NK/T-cell lymphoma. Almost all patients with NK/T-cell lymphoma showed a strong association with the Epstein-Barr virus by in situ hybridization studies. Sixty-five patients (81%) patients achieved complete remission after initial treatment, but 36 (55%) of these subsequently experienced treatment failure. Although there were no significant differences in locoregional failure rates among the patients of the three groups, distant failure was far more common in B-cell or NK/T-cell lymphoma than in T-cell lymphoma (p =.005). Most B-cell lymphoma cases showed a predilection for sites of systemic failure in the nodal and extranodal sites below the diaphragm, such as the paraaortic lymph nodes or the gastrointestinal (GI) tract, whereas patients with NK/T-cell lymphoma showed an increased risk of systemic dissemination to the skin, testes, or GI tract, including the development of hemophagocytic syndrome. The 5-year actuarial and disease-free survival rates for all patients were 57% and 51%, respectively. Of the three subtypes of primary sinonasal lymphomas, T-cell lymphoma seemed to carry the most favorable prognosis and NK/T-cell lymphoma the worst. (The 5-year actuarial survival rate was 57% for B-cell lymphoma, 80% for T-cell lymphoma, 37% for NK/T-cell lymphoma; p =.02, log-rank.) By univariate and multivariate analyses, immunophenotype was identified as the most important prognostic factor.

CONCLUSIONS

Our data indicate that the three subtypes of primary sinonasal lymphomas classified by immunohistochemical studies exhibit different clinical profiles, different patterns of failure, and different treatment outcomes. Given these observations, it is concluded that the recognition of these distinct subsets, diagnosed on the basis of immunophenotypic study, is very important and clinically relevant in predicting their potential behavior and prognosis.

Allelotyping of gastrointestinal nasal-type NK/T-cell lymphoma

Nasal-type natural killer/T-cell lymphoma (NKL) is a rare but distinct malignancy that often involves the mid-facial region and the gastrointestinal tract. This study is the first genome-wide allelotyping analysis on this rare lymphoma. We applied 382 microsatellite markers covering loci which spanned 22 autosomes to screen for allelic imbalances (AI) in six intestinal NKL. The most common chromosomal regions of allelic imbalances were found in 11p, 9q and 13q. Novel spots of allelic losses spots found at 2p21, 2q37.22, 18p11.21 and 18q12.1. In spite of presence of a few recurrent loci of imbalances, the allelotyping results show that NKL is heterogeneous.

Assessment of Epstein-Barr virus association with pediatric non-hodgkin lymphoma in immunocompetent and in immunocompromised patients in Argentina

CONTEXT

Epstein-Barr virus (EBV) has been classically associated with 3 malignancies, Burkitt lymphoma, B-cell lymphoproliferative syndromes, and nasopharyngeal carcinoma, and more recently with Hodgkin disease, T-cell lymphomas, and gastric and breast carcinomas, as well as with leiomyosarcoma and leiomyoma associated with immunosuppression.

OBJECTIVE

To compare EBV expression in Argentine tumor samples with those reported elsewhere, we analyzed EBV expression in an Argentine pediatric population with non-Hodgkin lymphoma and correlated these results with clinical course and outcome.

METHODS

We studied EBV presence by latent membrane protein-1 protein labeling by immunohistochemistry, by in situ hybridization, and by polymerase chain reaction for Epstein-Barr-encoded RNAs (EBERs) in formalin-fixed and paraffin-embedded non-Hodgkin lymphoma tissue samples (collected retrospectively) from 32 pediatric patients at Ricardo Gutiérrez Children's Hospital from 1993 to 2000.

RESULTS

Eight out of the 32 (25%) non-Hodgkin lymphoma cases showed latent membrane protein-1 and EBERs by in situ hybridization positive staining in tumor cells. Among EBERs and latent membrane protein-1-positive cases, there were 5 immunocompromised patients, with either human immunodeficiency virus infection or primary immunodeficiency. The EBERs in situ hybridization results were confirmed by EBERs polymerase chain reaction in good-quality DNA from 11 samples, with 3 proving positive and 8 negative.

CONCLUSIONS

The association of EBV with non-Hodgkin lymphoma in the Argentine pediatric population was low (25%), and this figure rose to 100% when only the immunocompromised patients subgroup was considered, confirming that the virus is probably a cofactor in the lymphomagenesis of some but not all pediatric non-Hodgkin lymphoma. So far, no differences in clinical outcome are discernible between EBV-positive and EBV-negative non-Hodgkin lymphoma patients.