Treatment of advanced extranodal NK/T cell lymphoma, nasal-type and aggressive NK-cell leukemia

EBV associated T- and NK-cell lymphoproliferative diseases: A comprehensive overview of clinical manifestations and novel therapeutic insights

EBV is a ubiquitous virus that infects nearly all people around the world. Most infected people are asymptomatic and do not show serious sequelae, while others may develop Epstein-Barr virus (EBV)-positive T and NK-cell lymphoproliferations characterised by EBV-infected T or NK cells. These disorders are more common in Asian and Latin American people, suggesting genetic predisposition as a contributing factor. The revised WHO classification classifies the lymphoproliferative diseases as: extranodal NK/T-cell lymphoma nasal type (ENKTL), aggressive NK-cell leukemia (ANKL), primary EBV-positive nodal T or NK cell lymphoma (NNKTL), systemic EBV-positive T-cell lymphoproliferative disease of childhood (STCLC), systemic chronic active EBV infection (sys CAEBV), hydroa-vacciniforme (HV) and severe mosquito bite allergy (SMBA). Recent advances in the molecular pathogenesis of these diseases have led to the development of new therapeutic strategies. Due to the infrequency of the diseases and broad clinicopathological overlap, the diagnosis and classification are challenging for both clinicians and pathologists. In this article, we aim to review the recent pathological findings which can be helpful for designing new drugs, clinical presentations and differential diagnoses, and suggested therapeutic interventions to provide a better understanding of these rare disorders.

Primary adrenal extranodal NK/T-cell lymphoma: A case report and literature review

A 37-year-old man was admitted to our department following the detection of bulky tumors in his bilateral adrenal glands. A biopsy resulted in the diagnosis of extranodal NK/T cell lymphoma, nasal type (ENKL). After debulking by chemotherapy, allogeneic hematopoietic stem cell transplantation (alloHCT) was performed. Relapses in the liver and adrenal glands were identified 2 months post alloHCT, for which temporary administration of l-asparaginase resulted in complete metabolic response. However, multiple relapses in the central nervous system and lethal lymphomatous meningitis successively developed. Primary adrenal ENKL could tend to present as bulky lesion and follow an aggressive clinical course.

Extranasal extranodal NK/T-cell lymphoma associated with systemic lupus erythematosus

Increased incidence of lymphoproliferative disorders is reported in patients with autoimmune diseases, majority of which have a B-cell phenotype and are pathogenetically associated with the reactivation of Epstein-Barr virus (EBV). However, EBV-associated T/NK-cell lymphoma has hardly been reported. We present the case of a 68-year-old-woman, who had been diagnosed with systemic lupus erythematosus (SLE) 28 years back and was treated with various immunosuppressive agents including steroids, cyclophosphamide, and tacrolimus. She presented with a progressively worsening swelling of the right thigh for the last few months. Radiological examination revealed an intramuscular bulky tumor without any other lesions and the biopsy results led to a diagnosis of extranodal NK/T-cell lymphoma, nasal type (ENKL). Concurrent chemoradiotherapy resulted in a complete response, which has been sustained for more than 2 years without requiring additional therapy. After the initiation of chemotherapy, SLE did not worsen with the administration of low-dose corticosteroids. To the best of our knowledge, this is the first case report of a localized extranasal ENKL developing in a patient with SLE.

NK-Cell Lymphomas

NK-cell malignancies are rare aggressive diseases associated with poor clinical outcome. There is a significant geographic variation in their incidence. At least a part of the reason for that is the fact that Epstein-Barr virus plays an important role in pathogenesis, and importantly, the plasma viral titer reflects disease burden and response to therapy. Extranodal NK/T-cell lymphoma, nasal type (ENKL), is the most common disease subtype in NK-cell malignancies. Conventional anthracycline-based chemotherapy was historically used for ENKL, only to produce dismal outcome. More recently, concurrent chemoradiation therapy for early-stage disease and non-anthracycline-based L-asparaginase containing chemotherapy have been studied, showing improved clinical response and survival, with long-term survival rates of 60-70% and 50-60%, respectively. Stem cell transplant can provide long-term disease control in recurrent or refractory disease settings, but the role of frontline use of such approach is yet to be determined. Several novel therapeutic approaches have shown promising results, and enrollment to clinical trials is the essential key to improve the treatment outcome in the future.

Peripheral T-cell Lymphomas: Updates in Allogeneic Hematopoietic Stem Cell Transplantation

Objective:

Peripheral T-cell lymphomas (PTCLs) confer dismal prognosis and no consensus has been established on the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to its rarity and heterogeneity. The purpose was to review key points of allo-HSCT for PTCLs, including indication, times of transplantation, conditioning regimen, graft versus host disease prophylaxis, and treatment of relapse.

Data Sources:

A comprehensive search in PubMed and Cochrane up to February 28, 2018, with the keywords “Peripheral”, “T”, “Lymphoma”, and “Transplantation” was done.

Study Selection:

Relevant articles including HSCT for PTCLs were carefully reviewed.

Results:

Promising data have been reported from advances in transplant technology and more and more PTCLs patients with poor prognosis could benefit from allo-HSCT.

Conclusion:

Allo-HSCT is a useful choice for patients with refractory/relapsed PTCLs or high-risk new diagnosed PTCLs.

Hematopoietic Stem Cell Transplantation for the Treatment of Epstein-Barr Virus-Associated T- or NK-Cell Lymphoproliferative Diseases and Associated Disorders

Chronic active Epstein-Barr virus infection (CAEBV) is a prototype of EBV-associated T- and/or NK-cell (EBV⁺ T/NK-cell) lymphoproliferative disorders. Most subtypes of these are lethal. We established a unified treatment strategy composed of step 1 (immunochemotherapy: steroids, cyclosporine A, and etoposide), step 2 (multi-drug block chemotherapy), and step 3 (allogeneic hematopoietic stem cell transplantation; HSCT) for CAEBV and its related diseases. Allogeneic HSCT is the only cure for CAEBV with few exceptions. Primary-EBV infection-associated hemophagocytic lymphohistiocytosis (primary-EBV HLH) is also an EBV⁺ T/NK-cell lymphoproliferation. The nature of EBV⁺ T/NK cells in CAEBV and those in primary-EBV HLH differ. In primary-EBV HLH, most patients need step 1 only and some require step 2 for the successful induction of apoptosis in EBV-infected T cells; however, some exceptional patients require HSCT. We herein present our single institutional experience of CAEBV and primary-EBV HLH, together with that of post-transplant EBV⁺ T/NK-cell lymphoproliferative disease. We also discuss some practical points on HCST with a review of the literature.

CD56-Negative Aggressive NK Cell Leukemia Relapsing as Multiple Cranial Nerve Palsies: Case Report and Literature Review

Background

Aggressive natural killer cell leukemia (ANKL) is extremely rare and habitually manifests as a systemic disease with multiorgan failure that rapidly evolves to death. The neoplastic natural killer (NK) cells usually harbor the Epstein-Barr virus (EBV) with a latent viral infection pattern type II; they often have a cytoplasmic CD3ε⁺ and surface CD3⁻, CD2⁺, and CD56⁺ immunophenotype, and they show complex genetic abnormalities affecting multiple tumor suppressor genes and oncogenes. We present a rare case of CD56-negative ANKL and review the clinical and laboratorial criteria for the diagnosis, as well as the available therapies.

Case Presentation

A European 36-year-old male presented with acute onset fever, pallor, weakness, and jaundice. He had hepatosplenomegaly, severe pancytopenia, hepatic cytolysis, and very high serum lactic dehydrogenase levels. The bone marrow studies resulted in the diagnosis of an EBV-positive, CD56-negative ANKL. The patient failed to respond to gemcitabine and cisplatin-based polychemotherapy, dying three months later with leukemic meningitis and multiple cranial nerves palsies.

Conclusions

The diagnosis of ANKL is difficult and requires both clinical suspicion and an extensive laboratorial approach. Absence of CD56 expression on the neoplastic NK cells may impose difficulties in the diagnosis, which requires morphological, immunophenotypic, histopathological, immunohistochemical, cytogenetic, and molecular studies.

Integrated genomic analysis identifies deregulated JAK/STAT-MYC-biosynthesis axis in aggressive NK-cell leukemia

Aggressive NK-cell leukemia (ANKL) is a rare form of NK cell neoplasm that is more prevalent among people from Asia and Central and South America. Patients usually die within days to months, even after receiving prompt therapeutic management. Here we performed the first comprehensive study of ANKL by integrating whole genome, transcriptome and targeted sequencing, cytokine array as well as functional assays. Mutations in the JAK-STAT pathway were identified in 48% (14/29) of ANKL patients, while the extracellular STAT3 stimulator IL10 was elevated by an average of 56-fold (P < 0.0001) in the plasma of all patients examined. Additional frequently mutated genes included TP53 (34%), TET2 (28%), CREBBP (21%) and MLL2 (21%). Patient NK leukemia cells showed prominent activation of STAT3 phosphorylation, MYC expression and transcriptional activities in multiple metabolic pathways. Functionally, STAT3 activation and MYC expression were critical for the proliferation and survival of ANKL cells. STAT signaling regulated the MYC transcription program, and both STAT signaling and MYC transcription were required to maintain the activation of nucleotide synthesis and glycolysis. Collectively, the JAK-STAT pathway represents a major target for genomic alterations and IL10 stimulation in ANKL. This newly discovered JAK/STAT-MYC-biosynthesis axis may provide opportunities for the development of novel therapeutic strategies in treating this subtype of leukemia.

Resveratrol inhibits Extranodal NK/T cell lymphoma through activation of DNA damage response pathway

Background

Extranodal NK/T cell lymphoma (NKTCL) is a highly aggressive non-Hodgkin lymphoma with poor prognosis. Resveratrol (RSV, 3,5,4′-trihydroxystilbene), a natural nontoxic phenolic compound found in the skin of grapes and some other spermatophytes, performs multiple bioactivities, such as antioxidant activity, anti-aging activity, reduction of cardiovascular disease risk and anticarcinogenic effect. Here we report the anti-tumor effect of RSV in NKTCL cell lines SNT-8, SNK-10 and SNT-16.

Results

RSV inhibited NKTCL cell proliferation in a dose- and time-dependent manner and arrested cell cycle at S phase. It induced NKTCL cells apoptosis through mitochondrial pathway, shown as down-regulation of MCl-1 and survivin, up-regulation of Bax and Bad, and activation of caspase-9 and caspase-3. In addition, we found that RSV suppressed the phosphorylation level of AKT and Stat3, and activated DNA damage response (DDR) pathway directly or through up-regulation of Zta of Epstein-Barr virus (EBV). Furthermore, using KU55933 as the inhibitor of pATM, we verified that DDR played an important role in RSV inducing NKTCL apoptosis. RSV also showed synergistic effect on activating DDR pathway in combination with etoposide or ionizing radiation, which resulted in cell proliferation inhibition and apoptosis.

Conclusions

Our results provide in vitro evidence that RSV produces anti-tumor effect by activating DDR pathway in an ATM/Chk2/p53 dependent manner. So we suggest that RSV may be worthy for further study as an anti-tumor drug for NKTCL treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0601-6) contains supplementary material, which is available to authorized users.

Extranodal NK/T Cell Lymphoma, Nasal Type (ENKTL-NT): An Update on Epidemiology, Clinical Presentation, and Natural History in North American and European Cases

PURPOSE OF REVIEW

Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT) is an aggressive extranodal non-Hodgkin lymphoma most commonly occurring in East Asia and Latin America but with increasing incidence in the United States. Data on epidemiology, disease presentation, and outcome for European and North American ("Western") cases are very limited. We review published landmark clinical studies on ENKTL-NT in the West and report in detail recent data, including our institutional experience.

RECENT FINDINGS

We highlight key observations in its epidemiology, natural history, and trends in clinical management. In the USA, ENKTL-NT is more common among Asian Pacific Islanders (API) and Hispanics compared to non-Hispanic whites. Published studies indicate less heterogeneity in clinical presentation in Western ENKTL-NT compared to Asian patients. While there is variation in age at diagnosis, presence of antecedent lymphoproliferative disorders, and outcomes among racial/ethnic groups, the universal association of ENKTL-NT with EBV and the poor response of this neoplasm to anthracycline-based therapy is consistent across all geographic areas. Data on epidemiology, disease presentation, and clinical outcomes in mature T cell and NK cell (T/NK cell) neoplasms, including ENKTL-NT, in Europe and North America are very limited. As the classification and diagnostic characterization of the currently recognized T/NK cell lymphoma disease entities continue to evolve, gaps and inconsistencies in data reporting across different studies are being recognized. Despite these limitations, several studies from the USA suggest that the incidence of ENKTL-NT is higher in Asian Pacific Islanders (API) and non-white Hispanics and that outcomes may be worse in non-whites. However, the universal association of ENKTL-NT with Epstein-Barr virus (EBV) across all ethnic groups suggests a common pathogenesis. Given the overlap between the entities included in the category of T/NK cell neoplasms, there is a need to further define biological and clinical differences that may affect diagnosis, treatment, and outcome.

Clinicopathologic Characterization of Aggressive Natural Killer Cell Leukemia Involving Different Tissue Sites

Aggressive natural killer cell leukemia (ANKL) is a rare disease with an extremely aggressive clinical course. The etiology of ANKL is unclear with few genetic/epigenetic aberrations described to date. Moreover, misdiagnosis of ANKL is a frequent problem. Clinicopathologic characteristics of 35 retrospective cases of ANKL were investigated with the aim of improving diagnosis and to find the genetic/epigenetic aberrations associated with ANKL etiology. Because of the relatively low number of leukemic cells in the peripheral blood and bone marrow, diagnosis of ANKL can be missed; therefore, it is important to perform biopsy on solid tissues, if necessary. We describe the pathology of ANKL in the lymph nodes, bone marrow, spleen, liver, and skin, with focus on diagnosis and differentiated diagnosis. We observed young male predominance in our cohort, and the clinical course was more aggressive than reported previously. Low lactate dehydrogenase (<712 IU/L), chemotherapy or L-asparaginase administration were found to be associated with more favorable outcomes. SH2 domains of STAT5B and STAT3 also were screened for the presence of activating mutations. Moreover, CpG island methylation status of HACE1, a candidate tumor-suppressor gene, was determined in ANKL samples. We observed activating STAT5B mutations (1/5) and hypermethylation of HACE1 (3/4) in ANKL cases, suggesting that these aberrations may contribute to ANKL pathogenesis.

Allogeneic Hematopoietic Cell Transplantation for Aggressive NK Cell Leukemia. A Center for International Blood and Marrow Transplant Research Analysis

Aggressive NK cell leukemia (ANKL) is an exceedingly rare form of leukemia and carries a poor prognosis, with a median survival of only 2 months. Using the Center for International Blood and Marrow Transplant Research database, we evaluated outcomes of allogeneic hematopoietic cell transplantation (alloHCT) in patients with ANKL. Twenty-one patients with a centrally confirmed diagnosis of ANKL were included. Median patient age was 42 years and 15 patients (71%) were Caucasian. Fourteen patients (67%) were in complete remission (CR) at the time of alloHCT, and 5 patients had active disease. Median follow-up of survivors was 25 months (range, 12 to 116). The 2-year estimates of nonrelapse mortality, relapse/progression, progression-free (PFS), and overall survival (OS) were 21%, 59%, 20%, and 24%, respectively. The 2-year PFS of patients in CR at the time of alloHCT was significantly better than that of patients with active disease at transplantation (30% versus 0%; P = .001). The 2-year OS in similar order was 38% versus 0% (P < .001). In conclusion, this registry analysis that included majority non-Asian patient population shows that alloHCT can provide durable disease control in a subset of ANKL patients. Achieving CR before transplantation appears to be a prerequisite for successful transplantation outcomes.

Gene expression analysis of hypersensitivity to mosquito bite, chronic active EBV infection and NK/T-lymphoma/leukemia

The human herpes virus, Epstein-Barr virus (EBV), is a known oncogenic virus and plays important roles in life-threatening T/NK-cell lymphoproliferative disorders (T/NK-cell LPD) such as hypersensitivity to mosquito bite (HMB), chronic active EBV infection (CAEBV), and NK/T-cell lymphoma/leukemia. During the clinical courses of HMB and CAEBV, patients frequently develop malignant lymphomas and the diseases passively progress sequentially. In the present study, gene expression of CD16^(-)CD56⁽⁺⁾-, EBV⁽⁺⁾ HMB, CAEBV, NK-lymphoma, and NK-leukemia cell lines, which were established from patients, was analyzed using oligonucleotide microarrays and compared to that of CD56^brightCD16^dim/- NK cells from healthy donors. Principal components analysis showed that CAEBV and NK-lymphoma cells were relatively closely located, indicating that they had similar expression profiles. Unsupervised hierarchal clustering analyses of microarray data and gene ontology analysis revealed specific gene clusters and identified several candidate genes responsible for disease that can be used to discriminate each category of NK-LPD and NK-cell lymphoma/leukemia.

Clinical Features, Pathogenesis, and Treatment of Large Granular Lymphocyte Leukemias

Large granular lymphocytes (LGLs) are large lymphocytes with azurophilic granules in their cytoplasm. LGLs are either natural killer (NK) cells or T lymphocytes. Expansions of the LGLs in the peripheral blood are seen in various conditions, including three clonal disorders: T-cell LGL (T-LGL) leukemia, chronic lymphoproliferative disorders of NK cells (CLPD-NK), and aggressive NK-cell leukemia (ANKL). However, the monoclonal and polyclonal expansion of LGLs has been associated with many other conditions. The present article describes these LGL disorders, with special emphasis on the clinical features, pathogenesis, and treatments of the three above-mentioned clonal disorders.

Clinical features and treatment outcome of Epstein-Barr virus-positive nodal T-cell lymphoma

The classification of mature NK-/T-cell lymphoma mainly originating from the T-cell lineage with predominantly nodal involvement and Epstein-Barr virus (EBV) positivity in a majority of tumor cells is unresolved. We analyzed the clinical features and treatment outcomes of such patients. Five patients with EBV-positive nodal T-cell lymphoma were surveyed during follow-up period. The median age was 53 years (range 33-88 years), and all patients showed nodal involvement. The patients mostly presented advanced clinical features, such as stage III or IV disease, elevated lactate dehydrogenase, and hemophagocytosis. Four patients received cyclophosphamide-containing chemotherapy at the time of diagnosis. However, three patients (75 %) showed disease progression during the early cycles of initial treatment. The median overall survival was 1.5 months (95 % CI 0.0-3.4 months). Patients with EBV-positive nodal T-cell lymphoma mainly show lymph node involvement, but also show aggressive clinical features and poor treatment outcomes, such as aggressive NK-cell leukemia. Therefore, we should consider EBV-positive nodal T-cell lymphoma to be a unique disease entity distinct from peripheral T-cell lymphoma not otherwise specified.

L-asparaginase-based regimens followed by allogeneic hematopoietic stem cell transplantation improve outcomes in aggressive natural killer cell leukemia

Aggressive nature killer cell leukemia (ANKL) is a mature NK-T cell lymphoma with worse prognosis, but optimal treatment is unclear. Therefore, we analyzed the efficacy of l-asparaginase-based regimens for ANKL patients. Twenty-one patients who received dexamethasone, methotrexate, ifosfamide, l-asparaginase, and etoposide (SMILE) or etoposide, ifosfamide, dexamethasone, and l-asparaginase (VIDL) chemotherapy at Samsung Medical Center were selected. The overall response rate for all patients was 33 % (7/21); 38 % (5/13) in SMILE and 40 % (2/5) in VIDL, respectively. The median progression-free survival was 3.9 months (95 % CI 0.0–8.1 months) and median overall survival was 7.0 months (95 % CI 2.3–11.7 months). Treatment response (P = 0.001), hematopoietic stem cell transplantation (HSCT) (P = 0.007) and negative conversion of Epstein-Barr virus (EBV) DNA titer after treatment (P = 0.004) were significantly associated with survival. Thus, l-asparaginase-based regimens followed by allogeneic HSCT seem to improve the outcome for ANKL patients.

Long complete remission achieved with the combination therapy of Cisplatin and gemcitabine in a patient with aggressive natural killer cell leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare and often lethal lymphoproliferative disorder. Patients may present with constitutional symptoms, jaundice, skin infiltration, lymphadenopathy, and hepatosplenomegaly. ANKL can progress quickly to multiorgan failure and survival is usually measured in weeks. Although a rapid and accurate diagnosis is critical, unfortunately there is no hallmark diagnostic marker of ANKL. We report a case of a 48-year-old male who was able to obtain a complete remission following cisplatin-based chemotherapy. We describe the details of the chemotherapy regimens used and a literature review of the treatment of ANKL.

Spontaneous Hepatic Rupture Associated With Epstein-Barr Virus Negative Aggressive Natural Killer Cell Leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare subtype of large granular lymphocyte (LGL) leukemia, which typically presents in young adults of Asian descent. It is an aggressive disease, characterized initially by fever, pancytopenia and hepatosplenomegaly, which rapidly progresses to organ failure and death over the course of months. Spontaneous hemorrhagic complications have been reported to occur in ANKL in a handful of case reports, including lethal intestinal and cerebral hemorrhage as well as splenic rupture. Here, we present a case of a 49-year-old man with Epstein-Barr virus (EBV)-negative ANKL who developed fatal spontaneous hepatic rupture approximately 4 months after initial diagnosis. To the best of our knowledge, this is first reported case of hepatic rupture associated with ANKL.

Interobserver variation in classifying lymphomas among hematopathologists

Background

Lymphomas are common malignancies that have various subtypes with many overlapping histologic, immunophenotypic and genetic features. Therefore, discordance in classifying lymphoma among pathologists may be encountered. But this issue is not well characterized. We conducted the present study to demonstrate discordances among Thai hematopathologists as well as to highlight common arguing points for classifying lymphomas.

Methods

The 117 lymphoma cases were randomly retrieved and individually reviewed by 7 hematopathologists, members of the “Thai Hematopathologist Group,” without knowing the original diagnoses. The consensus diagnoses were given from a discussion by all members. In each case, the diagnosis from each participant was compared with the consensus diagnosis and classified into 4 categories as follow: 1) concordance, 2) minor discordance, 3) major discordance and 4) serious discordance.

Results

There were approximately 11% discordances between original and consensus diagnoses. The average discordances among all pathologists according to minor, major and serious discordances were 10%, 3.5% and 0.3%, respectively. Diffuse large B-cell lymphoma had the least discordance (7%). Small biopsies had been found to increase discordances in some lymphoma subtypes.

Conclusions

The present study reveals some degrees of interobserver variation in classifying of lymphoma by using the 2008 WHO classification among hematopathologists. Some types of lymphomas on small biopsies were found to have a significant higher discordance rate. This study also described some common diagnostic discordances regarded as potential pitfalls in classifying lymphomas.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_162

Series of extranodal natural killer/T-cell lymphoma, nasal type, with periorbital involvement

PURPOSE

To describe the clinical presentation, diagnosis and treatment of periorbital extranodal natural killer/T-cell lymphoma, nasal type.

METHODS

Case series of three patients with periorbital involvement of extranodal natural killer/T-cell lymphoma, nasal type, of whom clinical data, orbital imaging and immunohistochemical analysis were collected. For the purpose of this study, all histopathological and immunohistochemical slides were re-examined.

RESULTS

All patients presented with painless eyelid swelling and a history of sinonasal disease, of whom one with bilateral panuveitis, not responding to systemic antibiotics. Extraocular muscle involvement was present in 2 cases upon presentation and in 1 case later on. Initial paranasal and orbital biopsies were negative in 2 patients, with only the second orbital biopsy leading to the diagnosis. Natural killer/T-cell and cytotoxic markers were present in all cases, as well as Epstein-Barr virus encoded RNA in situ hybridization. The patients died respectively 5, 9 and 35 months from diagnosis despite treatment with chemotherapy and radiotherapy.

CONCLUSION

Extranodal natural killer/T-cell lymphoma, nasal type, should be suspected in a painless periorbital cellulitis with chronic sinusitis, not responding to conventional therapy. A high index of suspicion is necessary in biopsies showing angiodestruction and necrosis. Epstein-Barr virus encoded RNA in situ hybridization and expert hematopathologist consultation is necessary to decrease the delay in diagnosis.

Prognostic impact of beta-2 microglobulin in patients with extranodal natural killer/T cell lymphoma

Although serum beta-2 microglobulin (B2M) has been suggested as an independent prognostic factor for several lymphoproliferative diseases, it has rarely been investigated in extranodal natural killer/T cell lymphoma (ENKTL). From a prospectively collected database, 145 patients with ENKTL were identified. Among them, a total of 101 patients were included in the analysis, with exclusion of patients without baseline serum B2M level and those did not receive anticancer therapy. Serum B2M (<3.0 vs. ≥3.0 mg/L) was analyzed for association with overall survival (OS). Seventy-nine (78 %) patients had nasal ENKTL, and 22 (22 %) had extranasal ENKTL. In overall patients, median OS was 26.7 months (95 % confidence interval (CI), not assessable), with a median follow-up of 32.4 months (range, 0.9-155.2 months). While median OS was not reached in patients with nasal ENKTL, extranasal ENKTL group had median OS of 5.1 months (95 % CI, 1.2-8.9 months; p < 0.001). Baseline serum B2M was significantly associated with OS in patients with nasal ENKTL (p < 0.001). This was consistent in limited (stages I and II) nasal ENKTL (p = 0.002) and disseminated (stages III and IV) nasal ENKTL (p = 0.02). However, there was no difference of OS in extranasal ENKTL patients (p = 0.69). In multivariate analysis including other prognostic factors, elevated serum B2M was significantly associated with poor OS (hazard ratio (HR) = 3.8, 95 % CI 1.7-8.2, p = 0.001, in a model including Korean Prognostic Index, and HR = 3.6, 95 % CI 1.6-8.2, p = 0.002, in a model including International Prognostic Index). In patients with nasal ENKTL, baseline serum B2M is a powerful prognostic factor. The prognostic value of B2M was independent of previously established prognostic models. Further investigations are necessary to validate the role of B2M in ENKTL.

Pathogenesis and treatment of extranodal natural killer/T-cell lymphoma

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKL) is one of the uncommon subtypes of malignant lymphoma, and predominantly occurs in the nasal or paranasal areas and less frequently in the skin. Previously, its prognosis was poor due to the expression of P-glycoprotein, which actively exports several anticancer agents outside the lymphoma cells. However, in recent years, novel therapeutic approaches such as simultaneous chemoradiotherapy or l-asparaginase-based regimens including SMILE (steroid, methotrexate, ifosfamide, l-asparaginase, and etoposide) improved the response to therapy and survival of ENKL patients. Epstein-Barr virus (EBV) is present in lymphoma cells of almost all patients, accounting for the pathogenesis of ENKL. Fragmented EBV-DNA is released from tumor cells, and can be detected in the peripheral blood of patients. The EBV-DNA copy numbers are associated with tumor burden, and can predict the prognosis of ENKL, as well as the toxicity against chemotherapy. Based on this recent progress, ENKL is currently categorized as a lymphoma with intermediate prognosis, but the overall treatment results are not satisfactory. Further improvement of the prognosis of ENKL is therefore warranted, including the optimal use of hematopoietic stem cell transplantation (HSCT).

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.

Aggressive mature natural killer cell neoplasms: from epidemiology to diagnosis

Mature natural killer (NK) cell neoplasms are classified by the World Health Organization into NK/T cell lymphoma, nasal type (NKTCL), aggressive NK-cell leukemia (ANKCL) and chronic lymphoproliferative disorders of NK-cells, the latter being considered provisionally. NKTCL and ANKCL are rare diseases, with higher prevalence in Asia, Central and South America. Most NKTCL present extranodal, as a destructive tumor affecting the nose and upper aerodigestive tract (nasal NKTCL) or any organ or tissue (extranasal NKTCL) whereas ANKCL manifests as a systemic disease with multiorgan involvement and naturally evolutes to death in a few weeks. The histopathological hallmark of these aggressive NK-cell tumors is a polymorphic neoplastic infiltrate with angiocentricity, angiodestruction and tissue necrosis. The tumor cells have cytoplasmatic azurophilic granules and usually show a CD45(+bright), CD2(+), sCD3(-), cytCD3epsilon(+), CD56(+bright), CD16(−/+), cytotoxic granules molecules(+) phenotype. T-cell receptor genes are in germ-line configuration. Epstein-Barr virus (EBV) -encoded membrane proteins and early region EBV RNA are usually detected on lymphoma cells, with a pattern suggestive of a latent viral infection type II. Complex chromosomal abnormalities are frequent and loss of chromosomes 6q, 11q, 13q, and 17p are recurrent aberrations. The rarity of the NK-cell tumors limits our ability to standardize the procedures for the diagnosis and clinical management and efforts should be made to encourage multi-institutional registries.

Favorable outcome in a child with EBV-negative aggressive NK cell leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare malignant disorder of mature NK cells frequently associated with Epstein-Barr virus (EBV). This malignancy is typically treated with intensive remission induction chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). EBV-negative ANKL and childhood ANKL, however, are not well defined and the optimal therapeutic strategy in these cases is poorly understood. Here, we present a unique pediatric EBV-negative ANKL patient who achieved a successful treatment outcome after intensified ALL type chemotherapy without allogeneic HSCT.

Aggressive natural killer-cell leukemia with jaundice and spontaneous splenic rupture: a case report and review of the literature

Aggressive natural killer cell leukemia/lymphoma (ANKL) is a rare aggressive form of NK-cell neoplasm. We report an uncommon case of 36-year-old male who showed jaundice and spontaneous splenic rupture. The diagnosis was established by the biopsy of liver and spleen. The monomorphous medium-size neoplastic cells infiltrated into portal areas and sinus of liver as well as the cords and sinus of the spleen. Necrosis, mitotic figures and significant apoptosis could be seen easily. These neoplastic cells demonstrated a typical immunophenotype of CD3ε+, CD56+, CD16+, Granzyme B+, TIA-1+. T-cell receptor γ (TCR-γ) gene rearrangement analysis showed germline configuration and the result of in situ hybridization for Epstein-Barr virus-encoded RNA (EBER-ISH) was positive. The patient has undergone an aggressive clinical course and died of multi-organ function failure 14 days later after admission. To the best of our knowledge, this is the first case of ANKL with spontaneous splenic rupture, and we should pay more attention to recognize it.

Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition

Natural killer (NK) cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

NK/T-cell lymphomas: pathobiology, prognosis and treatment paradigm

The current World Health Organization (WHO) classification includes two types of natural killer (NK)-cell lymphomas: extranodal NK/T-cell lymphoma, nasal type (ENKL), and aggressive NK-cell leukemia (ANKL). These diseases are mostly endemic to East Asia and Latin America. The Epstein-Barr virus (EBV) is usually detected in tumor cells, suggesting that EBV plays an important role in lymphomagenesis. At the site of origin, ENKL can be divided into two major subtypes: nasal and extranasal diseases. The advanced disease presentation, highly aggressive clinical course, and poor prognosis of the latter are analogous to ANKL. It is well known that P-glycoprotein, which is a product of the multi-drug resistance (MDR1) gene, is expressed on neoplastic cells of ENKL or ANKL. This is a major cause of the refractoriness of malignant lymphoma to conventional chemotherapeutic regimens containing anthracycline. Recent studies, however, have identified that L-asparaginase-containing regimens, such as SMILE (steroid, methotrexate, ifosfamide, L-asparaginase and etoposide), are effective for ENKL. Considering the myelotoxicity of SMILE, its use in the treatment of ANKL needs some modifications, but this treatment scheme is promising in improving the prognosis of NK-cell lymphomas.

Brentuximab vedotin in systemic T-cell lymphoma

INTRODUCTION

Brentuximab vedotin is an antibody-drug conjugate which consists of the anti-CD30 monoclonal antibody cAC10 conjugated with the cytotoxic agent monomethyl auristatin E (MMAE). Brentuximab vedotin has been approved by the US Food and Drug Administration for the treatment of relapsed or refractory Hodgkin's lymphoma (HL) and anaplastic large cell lymphoma (ALCL). The efficacy of brentuximab vedotin in other CD30(+) lymphomas is currently being investigated.

AREAS COVERED

In this paper, we review the currently available treatment options for systemic peripheral T-cell lymphomas (PTCL) and the role of brentuximab vedotin in relapsed or refractory ALCL. In addition, ongoing clinical trial of brentuximab vedotin in relapsed PTCL and combination therapy with other chemotherapies for initial treatment of CD30 lymphoma will also be reviewed.

EXPERT OPINION

Brentuximab vedotin has established its role in the treatment of relapsed or refractory HL and ALCL. In the next few years, the efficacy of this agent in other CD30(+) lymphomas will be described. The safety and efficacy of several brentuximab-based combination regimens, including use as frontline chemotherapy is under investigation.

Phase II study of SMILE chemotherapy for newly diagnosed stage IV, relapsed, or refractory extranodal natural killer (NK)/T-cell lymphoma, nasal type: the NK-Cell Tumor Study Group study

PURPOSE

To explore a more effective treatment for newly diagnosed stage IV, relapsed, or refractory extranodal natural killer/T-cell lymphoma, nasal type (ENKL), we conducted a phase II study of the steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) regimen.

PATIENTS AND METHODS

Patients with newly diagnosed stage IV, relapsed, or refractory disease and a performance status of 0 to 2 were eligible. Two cycles of SMILE chemotherapy were administered as the protocol treatment. The primary end point was the overall response rate (ORR) after the protocol treatment.

RESULTS

A total of 38 eligible patients were enrolled. The median age was 47 years (range, 16 to 67 years), and the male:female ratio was 21:17. The disease status was newly diagnosed stage IV in 20 patients, first relapse in 14 patients, and primary refractory in four patients. The eligibility was revised to include lymphocyte counts of 500/μL or more because the first two patients died from infections. No treatment-related deaths were observed after the revision. The ORR and complete response rate after two cycles of SMILE chemotherapy were 79% (90% CI, 65% to 89%) and 45%, respectively. In the 28 patients who completed the protocol treatment, 19 underwent hematopoietic stem-cell transplantation. The 1-year overall survival rate was 55% (95% CI, 38% to 69%). Grade 4 neutropenia was observed in 92% of the patients. The most common grade 3 or 4 nonhematologic complication was infection (61%).

CONCLUSION

SMILE chemotherapy is an effective treatment for newly diagnosed stage IV, relapsed or refractory ENKL. Myelosuppression and infection during the treatment should be carefully managed.