Allogeneic haematopoietic SCT for natural killer/T-cell lymphoma: a multicentre analysis from the Asia Lymphoma Study Group

Pulmonary extranodal NK/T-cell lymphoma: A clinicopathological analysis of five patients

Objective

Our goal was to investigate the clinicopathological features of extranodal natural killer (NK)/T-cell lymphoma (ENKTL).

Material and Methods

A total of five newly identified (5 biopsy samples) untreated cases of pulmonary ENKTL were collected between January 2016 and January 2024. The clinical characteristic pathology features on hematoxylin-eosin-staining sections, immunohistochemistry stating, treatment responses, and prognoses were retrospectively analyzed.

Results

Among the five patients, four were male and one was female, and their ages varied between 48 and 63 years. All five patients were initially diagnosed with stage IV disease. Histological examination revealed either scattered or localized clusters of highly pleomorphic tumor lymphocytes associated with necrosis and a significant presence of inflammatory cells. Most tumor cells expressed cluster of differentiation (CD)3, T-cell intracellular antigen-1, and granzyme B, whereas there was an absence of CD20, CD79a, or CD5 expression. The expression of CD56 was detected in four out of the five patients. Only two patients were tested for programmed cell death ligand 1, with one out of two patients exhibiting positivity (Tumor Proportion Score (TPS) 80%). The Ki-67 proliferation index varied from 40% to 90%. All patients tested positive for Epstein- Barr virus-encoded ribonucleic acid (RNA) (EBER) through fluorescence in situ hybridization (FISH). Five of the patients died during follow-up. Four of these patients underwent standard chemotherapy, with survival durations ranging from 3 to 24 months. One patient received only supportive treatment, resulting in a survival time of 1 month.

Conclusion

Pulmonary ENKTL is an uncommon, aggressive cancer associated with a bleak prognosis. The likelihood of misdiagnosis is high because of the presence of necrotic lesions and various cell types. Accurate diagnosis relies heavily on immunohistochemistry and EBER FISH. The aim of our study was to facilitate improved diagnosis of pulmonary ENKTL and to identify treatment strategies for affected individuals.

An evaluation of sugemalimab for the treatment of relapsed or refractory extranodal natural killer T-cell lymphoma

INTRODUCTION

Relapsed or refractory extranodal natural killer/T-cell lymphoma (R/R ENKTL) is a rare and aggressive subtype arising from natural killer or cytotoxic T-cells, predominantly affecting the nasal cavity and paranasal sinuses, lacking a standardized therapeutic approach. Sugemalimab, a fully human, full-length anti-PD-L1 immunoglobulin G4 (IgG4) monoclonal antibody (mAb), has been investigated in a Single-Arm, Multicenter, Phase II Study (GEMSTONE-201). The results demonstrated significant efficacy, favorable tolerability, and manageable adverse reactions of sugemalimab in R/R ENKTL. This study summarizes and compares the efficacy and safety profile of sugemalimab with several other PD-1/PD-L1 inhibitors in R/R ENKTL patients.

AREA COVERED

We included a Phase II study (GEMSTONE-201) of sugemalimab in R/R ENKTL.

EXPERT OPINION

The clinical trials have demonstrated superior efficacy of sugemalimab, evidenced by a complete response rate (CRR) of 35.9% and an overall response rate (ORR) of 44.9%. In comparison with other immune checkpoint inhibitors (ICIs), sugemalimab shows a notably higher CRR. Additionally, sugemalimab exhibits a manageable safety profile. Further evaluation of sugemalimab is required based on its efficacy and safety in real-world patient populations. Should sugemalimab be included in medical insurance in the future, it could potentially benefit a larger number of patients with R/R ENKTL.

Anti-PD-1 antibody (Tislelizumab) combined with gemcitabine and oxaliplatin for extranodal NK/T-cell lymphoma failing asparaginase: A multicenter phase II trial

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTCL) is almost always fatal after the failure of asparaginase. This phase II study aimed to investigate the efficacy and safety of tislelizumab combined with gemcitabine and oxaliplatin (Tisle-GemOx) in patients with ENKTCL failing asparaginase.

METHODS

Eligible patients received Tisle-GemOx as initial induction for 6-8 cycles at 21-day intervals. Responders continued tislelizumab maintenance every two months for two years. The primary endpoint was the best complete response rate (CRR).

RESULTS

As of September 2023, 32 patients were enrolled in our study. Among the 30 efficacy-evaluable patients, the best CRR was 60 %, meeting the primary efficacy endpoint. With a median follow-up of 22.6 months, the median progression-free survival (PFS) was 7.4 months and the 1-year PFS rate was 46.4 %. Subgroup analyses showed that shorter PFS was associated with previous lines of chemotherapy ≥ 2 (P = 0.034) and concomitant hemophagocytic lymphohistiocytosis (P = 0.040). Pseudo-progression was observed in three patients (10 %). The most common grade ≥ 3 toxicities were lymphopenia (25 %) and anemia (15.6 %).

CONCLUSIONS

Tisle-GemOx exhibits promising anti-tumor activity and manageable toxicities as a salvage therapy for ENKTCL failing asparaginase. Further long-term follow-up is necessary to evaluate the durability of the response with tislelizumab maintenance in this patient population.

Long-term survival and clinical implications of allogeneic stem cell transplantation in relapse/refractory lymphoma: A 20-year Singapore experience

Introduction

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a curative option for relapse/refractory (R/R) lymphomas that have failed autologous transplantation or for high-risk lymphomas in the upfront setting. We conducted a retrospective analysis on consecutive lymphoma patients who underwent allo-HSCT over a 20-year period (2003- 2022) at Singapore General Hospital and National University Hospital Singapore.

Method

A total of 121 patients were included in the study. Median age was 41 years. Diagnoses include Hodgkin lymphoma (HL, 15%), B-cell non- Hodgkin lymphoma (B-NHL, 34%), T-cell non-Hodgkin lymphoma (T-NHL, 31%) and natural killer T-cell lymphoma (NKTL, 20%). Moreover, 27% of patients had prior auto-haematopoietic stem cell transplanta-tion (auto-HSCT), and 84% received reduced intensity conditioning (RIC). Donor types were matched sibling donor (45%), matched unrelated donor (29%), haploidentical donor (19%) and cord blood (CB, 7%).

Results

After median follow-up of 56 months, estimated 4-year progression-free survival (PFS) and overall survival (OS) for all patients were 38% and 45%, respectively. Non-relapse mortality (NRM) was 15% at day 100 and 24% at 1 year. On univariate analysis, complete remission status at transplant and RIC confers superior OS. On multivariate analysis, HL was associated with superior OS compared to NHL, whereas matched unrelated donor transplant was associated with significantly inferior OS compared to matched sibling donor.

Conclusion

Long-term curative durability was observed with allo-HSCT for patients with relapsed/ refractory lymphomas. This real-world data serves as a valuable historical benchmark for future studies on lymphomas in Singapore and the Asia Pacific region.

The role of auto-HSCT in extranodal natural killer/T cell lymphoma

Objectives

Autologous hematopoietic stem cell transplantation (auto-HSCT) is considered optional consolidation therapy especially for relapsed/refractory extranodal NK/T-cell lymphoma (ENKL), but its applications to newly diagnosed advanced-stage ENKL is currently limited.

Methods

We collected 51 cases of newly diagnosed advanced-stage ENKL patients, including 26 with auto-HSCT and 25 with chemotherapy rather than HSCT, from our hospital between 2014/01 and 2023/12. We summarized the patients' characteristics, conducted survival analysis of the 51 cases, and analyzed the potential benefits of auto-HSCT to ENKL patients.

Results

It shows that after a median follow-up time of 39 months, the estimated 5-year overall survival (OS) of the 51 newly diagnosed advanced-stage ENKL patients is 73.4%, and their estimated 5-year progression-free survival (PFS) is 73.4%. For patients receiving auto-HSCT, the 5-year OS (91.7%) and PFS (91.0%) are significantly different from those of patients receiving chemotherapy without HSCT (OS 53.3%, PFS 54.5%) (p < 0.05). Univariate and multivariate analysis results suggest that only the l-asparaginase usage in chemotherapy showed significant impact on the OS, and none of concerned factors showed significant impact on the PFS.

Conclusions

Auto-HSCT is indeed an option to newly diagnosed advanced-stage ENKL, but further studies are still required for more strict disease management.

Establishment of ganglioside GD2-expressing extranodal NK/T-cell lymphoma cell line with scRNA-seq analysis

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKL), is characterized by Epstein-Barr virus infection and poor prognosis. We established a novel cell line, ENKL-J1, from bone marrow cells of an ENKL patient. We found that ENKL-J1 cells express the ganglioside GD2 (GD2) and that GD2-directed chimeric antigen receptor T cells exhibit cytotoxicity against ENKL-J1 cells, indicating that GD2 would be a suitable target of GD2-expressing ENKL cells. Targeted next-generation sequencing revealed TP53 and TET2 variants in ENKL-J1 cells. Furthermore, single-cell RNA sequencing in ENKL-J1 cells showed high gene-expression levels in the oncogenic signaling pathways JAK-STAT, NF-κB, and MAPK. Genes related to multidrug resistance (ABCC1), tumor suppression (ATG5, CRYBG1, FOXO3, TP53, MGA), anti-apoptosis (BCL2, BCL2L1), immune checkpoints (CD274, CD47), and epigenetic regulation (DDX3X, EZH2, HDAC2/3) also were expressed at high levels. The molecular targeting agents eprenetapopt, tazemetostat, and vorinostat efficiently induced apoptosis in ENKL-J1 cells in vitro. Furthermore, GD2-directed chimeric antigen receptor T cells showed cytotoxicity against ENKL-J1 cells in vivo. These findings not only contribute to understanding the molecular and genomic characteristics of ENKL; they also suggest new treatment options for patients with advanced or relapsed ENKL.

Few and far between: clinical management of rare extranodal subtypes of mature T-cell and NK-cell lymphomas

While all peripheral T-cell lymphomas are uncommon, certain subtypes are truly rare, with less than a few hundred cases per year in the USA. There are often no dedicated clinical trials in these rare subtypes, and data are generally limited to case reports and retrospective case series. Therefore, clinical management is often based on this limited literature and extrapolation of data from the more common, nodal T-cell lymphomas in conjunction with personal experience. Nevertheless, thanks to tremendous pre-clinical efforts to understand these rare diseases, an increasing appreciation of the biological changes that underlie these entities is forming. In this review, we attempt to summarize the relevant literature regarding the initial management of certain rare subtypes, specifically subcutaneous panniculitis-like T-cell lymphoma, hepatosplenic T-cell lymphoma, intestinal T-cell lymphomas, and extranodal NK/T-cell lymphoma. While unequivocally established approaches in these diseases do not exist, we make cautious efforts to provide our approaches to clinical management when possible.

"Sandwich" protocol based on modified SMILE regimen for children with newly extranodal NK/T cell lymphoma, nasal type: a single-arm, single-center clinical study

Extranodal NK/T-cell lymphoma, nasal type (ENKTL), which is a rare form of mature T/NK cell lymphoma in children, currently lacks a standardized first-line treatment approach. However, a treatment protocol known as the "sandwich" regimen has been used in children newly diagnosed with ENKTL. This protocol combines the administration of methotrexate, ifosfamide, etoposide, pegaspargase, and dexamethasone (referred to as SMILE) with the addition of radiotherapy (RT). From September 2017 to December 2020, a total of five patients were included in the study, consisting of three males and two females. The median age of onset was 10.6 years (range, 9.8 to 14.0 years). Among the patients, four had nasal/nasopharyngeal disease at stage II, while one patient had extra nasal disease involving the skin at stage IV. The median EBV-DNA level in plasma was 1.68 × 103 copies/ml (range, 0.44 to 21.1 × 103copies/ml). All the patients had good overall response after 2 cycles of chemotherapy and radiotherapy, including 4 of the patients who had a complete response and 1 of the patients with partial remission. The patient with stage IV received allogeneic hematopoietic stem cell transplantation after the EBV-DNA level was elevated again during treatment. One patient in the low-risk group experienced grade 4 oral mucositis, while no other severe complications or treatment-related deaths were observed. The median follow-up period was 22 months (range, 5 to 57 months). All five patients successfully completed their treatment, with four patients achieving event-free survival, and one patient was lost to follow-up. The median OS time and EFS time was 33 months (range: 18-57 months) and 20 months (range: 5-47 months), respectively. The sandwich protocol has demonstrated a high response rate, good tolerance to chemotherapy, and no treatment-related fatalities. However, further confirmation is necessary through additional clinical studies involving larger sample sizes. Clinical trial registration number: Due to modified SMILE regimens with sandwiched radiotherapy yielded promising outcomes in children ENKTL, we have carried out a phase II multicenter clinical trial (ChiCTR220005954) for children ENKTL in China to further verify the efficacy and safety.

Efficacy and safety of PD-1 inhibitor alone or combined with chemotherapy in patients with relapsed or refractory extranodal natural Killer/T cell lymphoma: A retrospective study

Extranodal natural killer/T cell lymphoma (ENKTL) patients typically face a grim prognosis after relapse or progression following asparaginase-based chemotherapy. Currently, programmed cell death protein-1 (PD-1) immune checkpoint blockade has shown promising efficacy as an optimal regimen for relapsed or refractory ENKTL (rrENKTL) patients. This study retrospectively investigated the efficacy, safety, and factors influencing the survival of 26 rrENKTL patients who underwent monoclonal antibody treatment using PD-1 (Sintilimab or Camrelizumab) alone or combined with chemotherapy from January 2018 to February 2022. The disease control rate was 73.1%, and the objective response rate was 50.0%. 15.4% of the patients achieved complete remission, and 34.6% achieved partial remission (PR). After a median follow-up of 12 (range 3-47) months, the median progression-free survival (PFS) and overall survival (OS) were 6.5 and 13.3 months. The 1-year PFS and OS rate were 23.1% and 53.8%. 96.2% of patients experienced at least one adverse event and 26.9% experienced grade 1-2 immune-related adverse events. PD-1 inhibitor improved rrENKTL patient survival, and the AEs were controlled. We also observed that the prognostic index for NK cell lymphoma including Epstein-Barr virus (EBV) (PINK-E) and the nomogram-revised risk indexz for ENKTL patients could help identify a potentially unfavorable prognosis in this era of immunotherapy. More attention should be paid to the presence of EBV after anti-PD-1 immunotherapy, as it more accurately indicates a poor prognosis.

Allogeneic hematopoietic stem cell transplantation for NK/T-cell lymphoma: an international collaborative analysis

Natural killer/T-cell lymphomas (NKTCL) represent rare and aggressive lymphoid malignancies. Patients (pts) with relapsed/refractory disease after Asparaginase (ASPA)-based chemotherapy have a dismal prognosis. To better define the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT), we conducted a retrospective analysis of data shared with the European Society for Blood and Marrow Transplantation (EBMT) and cooperating Asian centers. We identified 135 pts who received allo-HSCT between 2010 and 2020. Median age was 43.4 years at allo-HSCT, 68.1% were male. Ninety-seven pts (71.9 %) were European, 38 pts (28.1%) Asian. High Prognostic Index for NKTCL (PINK) scores were reported for 44.4%; 76.3% had >1 treatment, 20.7% previous auto-HSCT, and 74.1% ASPA-containing regimens prior to allo-HSCT. Most (79.3%) pts were transplanted in CR/PR. With a median follow-up of 4.8 years, 3-year progression-free(PFS) and overall survival were 48.6% (95%-CI:39.5-57%) and 55.6% (95%-CI:46.5-63.8%). Non-relapse mortality at 1 year was 14.8% (95%-CI:9.3-21.5%) and 1-year relapse incidence 29.6% (95%-CI:21.9-37.6%). In multivariate analyses, shorter time interval (0-12 months) between diagnosis and allo-HSCT [HR = 2.12 (95%-CI:1.03-4.34); P = 0.04] and transplantation not in CR/PR [HR = 2.20 (95%-CI:0.98-4.95); P = 0.056] reduced PFS. Programmed cell death protein 1(PD-1/PD-L1) treatment before HSCT neither increased GVHD nor impacted survival. We demonstrate that allo-HSCT can achieve long-term survival in approximately half of pts allografted for NKTCL.

Treatment of extranodal NK/T-cell lymphoma: From past to future

Extranodal NK/T-cell lymphoma (ENKTCL) is the most common subtype of T/NK-cell lymphoma in Asia and Latin America, but very rare in North American and Europe. Patient survival has improved significantly over the past two decades. However, standard treatment has not yet been established, although dozens of prospective trials have been conducted. To help understand how the treatment of ENKTCL has evolved in the past and what trends lie ahead, we have comprehensively reviewed the treatment of this aggressive malignancy, with a particular focus on neglected or unanswered issues, such as the optimal staging method, the best partner of asparaginase (Asp), the individualized administration of Asp, the preferred sequence of CT and RT and so on. Overall, the 5-year overall survival (OS) of patients with Ann Arbor stage I/II disease increased from < 50% in the early 20th century to > 80% in recent years, and the median OS of patients with Ann Arbor stage III/IV disease increased from < 1 year to more than 3 years. The improvement in patient survival is largely attributable to advances in radiation technology and the introduction of Asp and anti-PD-1/PD-L1 immunotherapy into practice. Radiotherapy is essential for patients with early-stage disease, while Asp-based chemotherapy (CT) and PD-1/PD-L1 inhibitors significantly improved the prognosis of patients with advanced-stage disease. ENKTCL management is trending toward simpler regimens, less toxicity, and higher efficacy. Novel drugs, such as manufactured T cells, monoclonal antibodies, and small molecule inhibitors, are being intensively investigated. Based on the fact that ENKTCL is highly resistant to cytotoxic drugs except Asp, and aggressive CT leads to higher toxicity rather than better outcomes, we recommend it is unnecessary to expend additional resources to compare different combinations of Asp with cytotoxic agents. Instead, more efforts should be made to optimize the use of Asp and immunotherapy to maximize efficacy and minimize toxicity, explore ways to overcome resistance to Asp and immunotherapy, identify novel treatment targets, and define subpopulations who may benefit more from specific treatments.

Extranodal natural killer/T-cell lymphoma: An overview on pathology and clinical management

Natural killer (NK)/T-cell lymphomas arise mainly from NK-cells and occasionally T-cells, and are universally infected with Epstein Barr virus (EBV). They are uncommon lymphomas more prevalent in Asian and Central/South American populations. NK/T-cell lymphomas are clinically aggressive and predominantly extranodal. The most commonly involved sites are the nasal cavity, followed by non-nasal sites including the skin, gastrointestinal tract and testis. The diagnosis of extranodal NK/T-cell lymphoma is established with histological and immunohistochemical examination, together with the demonstration of EBV in the tumour cells. Staging by positron emission tomography computed tomography is essential to inform the optimal management. Plasma EBV DNA quantification should be performed as it serves as a marker for prognostication and treatment response. Survival outcomes of patients with early-stage disease are good following treatment with nonanthracycline based chemotherapy, together with sequential/concurrent radiotherapy. For advanced-stage disease, asparaginase-containing regimens are mostly used and allogeneic haematopoietic stem cell transplantation should be considered for those at high risk of relapse. Salvage chemotherapy is largely ineffective for relapsed/refractory disease, which has a grave prognosis. Novel therapeutic approaches including immune check-point blockade, EBV-specific cytotoxic T-cells, and monoclonal antibodies are being investigated to improve outcomes for those with high risk and relapsed/refractory disease.

How we treat NK/T-cell lymphomas

Natural killer (NK)/T-cell lymphomas are aggressive malignancies with a predilection for Asian and South American populations. Epstein-Barr virus (EBV) infection in lymphoma cells is universal. Predominantly extranodal, NK/T-cell lymphomas are divided clinically into nasal (involving the nose and upper aerodigestive tract), non-nasal (involving the skin, gastrointestinal tract, testes, and other organs), and aggressive leukaemia/lymphoma (involving the marrow and multiple organs) subtypes. Initial assessment should include imaging with positron emission tomography computed tomography (PET/CT), quantification of plasma EBV DNA as a surrogate marker of lymphoma load, and bone marrow examination with in situ hybridization for EBV-encoded small RNA. Prognostication can be based on presentation parameters (age, stage, lymph node involvement, clinical subtypes, and EBV DNA), which represent patient factors and lymphoma load; and dynamic parameters during treatment (serial plasma EBV DNA and interim/end-of-treatment PET/CT), which reflect response to therapy. Therapeutic goals are to achieve undetectable plasma EBV DNA and normal PET/CT (Deauville score ≤ 3). NK/T-cell lymphomas express the multidrug resistance phenotype, rendering anthracycline-containing regimens ineffective. Stage I/II nasal cases are treated with non-anthracycline asparaginase-based regimens plus sequential/concurrent radiotherapy. Stage III/IV nasal, and non-nasal and aggressive leukaemia/lymphoma cases are treated with asparaginase-containing regimens and consolidated by allogeneic haematopoietic stem cell transplantation (HSCT) in suitable patients. Autologous HSCT does not improve outcome. In relapsed/refractory cases, novel approaches comprise immune checkpoint blockade of PD1/PD-L1, EBV-specific cytotoxic T-cells, monoclonal antibodies, and histone deacetylase inhibitors. Future strategies may include inhibition of signalling pathways and driver mutations, and immunotherapy targeting the lymphoma and its microenvironment.

Characteristics and Outcome of Extranodal NK/T-cell Lymphoma in North America: A Retrospective Multi-Institutional Experience

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTL) is rare and clinical data from non-Asian countries are lacking. It is unclear whether outcomes and disease natural history is similar to reported Asian series. We assessed characteristics and outcomes of patients with ENKTL from major North American centers.

PATIENTS AND METHODS

We retrospectively identified patients with newly-diagnosed CD56 + ENKTL and studied disease characteristics and clinical outcomes.

RESULTS

One hundred and twenty-one patients with ENKTL diagnosed between June 1990 and November 2012 were identified. Eighty-three patients (69%) had stage I/II disease and were treated with combined modality therapy (CMT) (n = 53), chemotherapy alone (CT) (n = 14) or radiotherapy alone (RT) (n = 16).  Thirty-eight patients (31%) had stage III/IV disease and were treated with CMT (n = 12), CT (n = 23), or RT (n = 3).  The median follow-up for the entire cohort was 51 months. Patients with stage I/II disease, compared to those with stage III/IV disease, had superior 2-year progression free survival (PFS) 43% vs 19% (P = .03) and overall survival (OS) 59% vs. 29% (P= .004). Outcomes were similar for stage I/II patients who received CMT vs. RT alone with 2-year PFS (53% vs. 47%; P= .91) and OS (67% vs. 67%; P= .58). No significant differences in outcomes were noted based on race/ethnicity.

CONCLUSIONS

This series represents a large experience of ENKTL treated at several major North American academic centers.  Our data are consistent with Asian studies: (1) majority of patients present with early-stage disease; (2) overall poor outcome regardless of race/ethnicity; (3) CMT likely yields favorable outcomes for suitable candidates with early-stage disease.

Progress of Hematopoietic Stem Cell Transplantation and Radiotherapy in the Treatment of Extranodal NK/T Cell Lymphoma

Extranodal Natural Killer/T-cell lymphoma (ENKTL) is an extremely rare type of lymphoma which is highly lethal. It mainly affects the midline area unfolding as a necrotic granulomatous and extremely disfiguring lesion. There are two subtypes of (NKTL); the most common one is nasal which appears in the nasal cavity including the nasopharynx, oropharynx, parts of the aero digestive tract and Waldeyer’s ring. While the other rarer subtype, appears in sites like the skin, testis, gastrointestinal tract, salivary glands and muscle. ENKTL is popular for the expression of multidrug resistance-associated P-glycoprotein, which not only plays the main role at exporting many antitumor agents outside tumor cells, but also makes the disease hard to treat. It is commonly associated with Epstein-Barr virus (EBV) infection and commonly occurs in Asian populations. However, there is no single unified consensus yet as to what is the standardized treatment for ENKTL. Radiotherapy alone treatment, has been considered as a first-line therapy for localized ENKTL, which later on was found to be insufficient for improving survival rates. Thus, the combination of chemotherapy and radiotherapy has been recommended as a therapeutic modality for localized ENKTL. Several combination modalities of radiotherapy and chemotherapy have been advised in clinical practice including concurrent, sequential and sandwich chemo radiotherapy. For the best treatment outcome, only patients with localized nasal ENKTL and low risk of treatment failure are eligible for radiotherapy. Both radiotherapy and hematopoietic stem cell transplantation (HSCT) have been used as treatment modalities in ENKTL patients. Upfront HSCT was performed for ENKTL, but it was associated with a very poor prognosis even for the limited-stage disease. The evidence supporting the use of HSCT to treat ENKTL was derived from the results of a series of phase 1 and 2 trials along with retrospective studies. The end result was a unified consensus that consolidative HSCT is not necessary in patients with newly diagnosed localized ENKTL who achieved complete response after treatment with any of the modern chemo radiotherapy regimens. Hence, HSCT is solely advised for advanced and relapsed NKTL. The main debate remains over which HSCT is the most suitable for patients with newly diagnosed advanced NKTL and relapsed NKTL.

Combination of atezolizumab and chidamide to maintain long-term remission in refractory metastatic extranodal natural killer/T-cell lymphoma: A case report

BACKGROUND

The prognosis of refractory extranodal natural killer/T-cell lymphoma (ENKTL) is poor. Recent data have indicated that immune checkpoint blockade with a programmed cell death protein-1 (PD-1) antibody in combination with administration of histone deacetylase inhibitors represents a potentially effective treatment strategy. Compared with PD-1 antibodies, programmed death-ligand 1 antibodies have fewer side effects. Here, we present a rare case of a patient with refractory metastatic ENKTL who achieved sustained remission of approximately 10 mo with minor adverse effects after combination therapy with atezolizumab, chidamide, and radiotherapy.

CASE SUMMARY

A 56-year-old woman underwent resection of a tumour in her left nasal cavity and was diagnosed with ENKTL (nasal type). Medical examination revealed tumours observed in the bilateral nasal mucosa, the subcutaneous soft tissue of the inner side of the left eye, the soft tissue of the nasopharynx, the bilateral tonsils, and the left preauricular, right hilar, bilateral neck lymph nodes and bone marrow. However, tomography/computed tomography showed increased metabolism of the bilateral nasal mucosa and subcutaneous soft tissue of the inner side of the left eye and newly increased metabolism of the left cervical lymph node after chemotherapy. Therefore, combination therapy with chidamide, atezolizumab, and radiotherapy was performed. Fortunately, the patient achieved a complete response following 10 mo of combination therapy.

CONCLUSION

The outcome in this case suggests that the combination of atezolizumab, chidamide, and radiotherapy is a promising regimen for treating refractory metastatic ENKTL following chemotherapy treatment failure.

Recent Advances in the Diagnosis and Treatment of Natural Killer Cell Malignancies

Simple Summary

Natural killer (NK)/T-cell lymphomas are aggressive extranodal Epstein–Barr virus (EBV)-positive malignancies. They can be divided into three subtypes: nasal (involving the nose and upper aerodigestive tract), non-nasal (involving skin, gastrointestinal tract, testis and other organs) and disseminated (involving multiple organs). Lymphoma cells are positive for CD3ε, CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asians. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial at diagnosis and follow-up. Stage I/II patients receive non-athracycline asparaginse-containing regimens, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients receive asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT). Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches include PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial.

Abstract

Natural killer (NK)/T-cell lymphomas are aggressive malignancies. Epstein–Barr virus (EBV) infection in lymphoma cells is invariable. NK/T-cell lymphomas are divided into nasal, non-nasal, and disseminated subtypes. Nasal NK/T-cell lymphomas involve the nasal cavity and the upper aerodigestive tract. Non-nasal NK/T-cell lymphomas involve the skin, gastrointestinal tract, testis and other extranodal sites. Disseminated NK/T-cell lymphoma involves multiple organs, rarely presenting with a leukaemic phase. Lymphoma cells are positive for CD3ε (not surface CD3), CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asian patients. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial evaluations at diagnosis and follow-up. Stage I/II patients typically receive non-athracycline regimens containing asparaginse, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients are treated with asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT) in suitable cases. Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches are needed, involving PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial in selected patients. Future strategies may include targeting of signalling pathways and driver mutations.

New Approaches for Treatment of Advanced Extranodal NK/T-Cell Lymphoma

Extranodal NK/T cell lymphoma (ENKL) is a rare subtype of lymphoma that shows a poor clinical outcome. The most common sites are the nasal cavity, nasopharynx, paranasal sinuses, tonsils and larynx. Because of P-glycoprotein expression on ENKL cells, ENKL is resistant to anthracycline-based chemotherapy. L-asparaginase-based chemotherapy with or without radiotherapy shows promising outcomes for advanced ENKL, but has limited efficacy in relapsed/refractory ENKL. immune-checkpoint inhibitors, histone deacetylase inhibitors, and monoclonal antibodies are being investigated. In this review, we summarize the new treatments for ENKL.

Review on natural killer /T-cell lymphoma

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is strongly associated with Epstein-Barr virus (EBV) and has a high prevalence in Asian and in Central and South America. About 85% of ENKTLs derive from NK cells and 15% from T-cells. Various factors have been implicated in the development of ENKTL. Molecular pathogenesis of NK/T-cell lymphomas include mutations of genes, involving in the Janus Kinase (JAK)/ signal transducer and activator of transcription (STAT) pathway, RNA helicase family, epigenetic regulation, and tumor suppression. The relationship between ENKTL and human leukocyte antigen (HLA) has been demonstrated. Radiotherapy (RT) plays a key role in the first-line treatment of early-stage. In stage III/IV diseases, non-anthracycline-regimens-containing L-asparaginase are recommended. Although clinical remission after L-asparaginase-based combination therapy has been achieved in the majority of patients with advanced-stage or relapsed/refractory(r/r) ENKL, the long-term overall survival is still poor. Recently, immunotherapy and new therapeutic targets have gained much attention. In this article, we discuss the pathogenesis, diagnosis, prognostic models and management options of ENKTL. This article is protected by copyright. All rights reserved.

Characteristics and Outcome of Extranodal NK/T-Cell Lymphoma in North America: A Retrospective Multi-Institutional Experience

BACKGROUND

Extranodal natural killer/T-cell lymphoma (ENKTL) is rare and clinicaldata from non-Asian countries are lacking. It is unclear whether outcomes and diseasenatural history is similar to reported Asian series. We assessed characteristics and outcomes of patients with ENKTL from major North American centers.

PATIENTS AND METHODS

We retrospectively identified patients with newly-diagnosedCD56 + ENKTL and studied disease characteristics and clinical outcomes.

RESULTS

121 patients with ENKTL diagnosed between June 1990 and November 2012 were identified. Eighty-three patients (69%) had stage I/II disease and were treatedwith combined modality therapy (CMT) (n=53), chemotherapy alone (CT) (n=14) orradiotherapy alone (RT) (n=16). Thirty-eight patients (31%) had stage III/IV diseaseand were treated with CMT (n=12), CT (n=23), or RT (n=3). The median follow-up forthe entire cohort was 51 months. Patients with stage I/II disease, compared to thosewith stage III/IV disease, had superior 2-year progression free survival (PFS) 43% vs19% (p=0.03) and overall survival (OS) 59% vs 29% (p=0.004). Outcomes were similarfor stage I/II patients who received CMT vs RT alone with 2-year PFS (53% vs 47%;p=0.91) and OS (67% vs 67%; p=0.58). No significant differences in outcomes werenoted based on race/ethnicity.

CONCLUSIONS

This series represents a large experience of ENKTL treated at several major North American academic centers.

OUR DATA ARE CONSISTENT WITH ASIAN STUDIES

1) majority of patients present with early-stage disease; 2) overall poor outcome regardless of race/ethnicity; 3) CMT likely yields favorable outcomes for suitable candidates with early-stage disease.

Determinants of response to daratumumab in Epstein-Barr virus-positive natural killer and T-cell lymphoma

Background

The potential therapeutic efficacy of daratumumab in natural killer T-cell lymphoma (NKTL) was highlighted when its off-label usage produced sustained remission in a patient with highly refractory disease. This is corroborated recently by a phase II clinical trial which established that daratumumab monotherapy is well tolerated and displayed encouraging response in relapsed/refractory NKTL patients. However, little is known regarding the molecular factors central to the induction and regulation of the daratumumab-mediated antitumor response in NKTL.

Methods

CD38 expression was studied via immunohistochemistry, multiplex immunofluorescence and correlated with clinical characteristics of the patient. The therapeutic efficacy of daratumumab was studied in vitro via CellTiter-Glo (CTG) assay, complement-dependent cytotoxicity (CDC), antibody-dependent cell cytotoxicity (ADCC), and in vivo, via a patient-derived xenograft mouse model of NKTL, both as a single agent and in combination with L-asparaginase. Signaling mechanisms were characterized via pharmacologic treatment, RNA silencing, flow cytometry and corroborated with public transcriptomic data of NKTL.

Results

Epstein-Barr virus-positive NKTL patients significantly express CD38 with half exhibiting high expression. Daratumumab effectively triggers Fc-mediated ADCC and CDC in a CD38-dependent manner. Importantly, daratumumab monotherapy and combination therapy with L-asparaginase significantly suppresses tumor progression in vivo. Ablation of complement inhibitory proteins (CIP) demonstrate that CD55 and CD59, not CD46, are critical for the induction of CDC. Notably, CD55 and CD59 expression were significantly elevated in the late stages of NKTL. Increasing the CD38:CIP ratio through sequential CIP knockdown, followed by CD38 upregulation via All-Trans Retinoic Acid treatment, potently augments complement-mediated lysis in cells previously resistant to daratumumab. The CD38:CIP ratio consistently demonstrates a statistically superior correlation to antitumor efficacy of daratumumab than CD38 or CIP expression alone.

Conclusion

This study characterizes CD38 as an effective target for a subset of NKTL patients and the utilization of the CD38:CIP ratio as a more robust identifier for patient stratification and personalisation of treatment. Furthermore, elucidation of factors which sensitize the complement-mediated response provides an alternative approach toward optimizing therapeutic efficacy of daratumumab where CDC remains a known limiting factor. Altogether, these results propose a strategic rationale for further evaluation of single or combined daratumumab treatment in the clinic for NKTL.

Outcome after hematopoietic stem cell transplantation in patients with extranodal natural killer/T-Cell lymphoma, nasal type: A French study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

We evaluated the outcome of 65 French patients with Extranodal NK/T-cell lymphoma, nasal type (ENKTL) undergoing hematopoietic stem cell transplantation (HSCT) (19 allogeneic and 46 autologous). Fifty-four patients (83%), most of which receiving L-asparaginase (L-aspa) containing regimens (81%), achieved complete or partial response at time of HCST. After a median follow-up of 79.9 months, 4-years progression-free survival (PFS) and overall survival (OS) were similar in both autologous and allogeneic groups (PFS: 34% vs. 26%, p = .12 and OS: 52% vs. 53%, p = .74). Response status at HSCT was the major independent prognostic factor on survival (OS: HR: 4.013 [1.137; 14.16], p = .031 and PFS: HR: 5.231 [1.625; 16.838], p = .006). As compared to control patients receiving chemotherapy and/or radiotherapy containing regimens only, upfront HSCT did not improve the outcome of responder patients, including those treated by L-aspa. However, it tends to provide survival benefit for relapsed patients with initial high-risk clinical features who achieved second remission. Whereas the place of HSCT in upfront therapy has still to be clarified, these data confirm that HSCT should be considered for consolidation in selected patients with relapsed ENKTL. Based on a large non Asian ENKTL cohort since the L-aspa era, this study provides some insight into the survival patterns of ENKTL patients with HSCT in the Western hemisphere and may give future direction for the next clinical trial design.

Article Topic/Title: Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome. Part II: Prognosis and Management

Primary cutaneous T-cell lymphomas (CTCLs) other than Mycosis Fungoides (MF) and Sézary syndrome (SS) encompass a heterogenous group of non-Hodgkin lymphomas with variable clinical course, prognoses, and management. With morphologic and histologic overlap among the CTCL subtypes and other T-cell lymphomas with cutaneous manifestations, thorough evaluation with clinicopathologic correlation and exclusion of systemic involvement are essential prior to initiating therapy. Staging and treatment recommendations vary depending on the subtype, clinical behavior, and treatment response. Generally, for subtypes where staging is recommended, Ann Arbor or TNM staging specific to CTCL other than MF or SS are used. For many subtypes, there is no standard treatment to date. Available recommended treatments range widely from no active or minimal intervention with skin-directed therapy to aggressive systemic therapies including multiagent chemotherapy with consideration for hematopoietic stem cell transplant. Emerging targeted therapies, such as brentuximab, a chimeric antibody targeting CD30, show promise in altering the disease course of non-MF/SS CTCLs.

Hematopoietic Stem Cell Transplantation in T Cell and Natural Killer Cell Lymphomas: Update on Recent Advances

Mature T and natural killer (NK) cell non-Hodgkin lymphoma (T-NHL) has a poor prognosis. Data from existing retrospective and prospective studies have suggested that high-dose chemotherapy followed by autologous hematopoietic cell transplantation (auto-HCT) may improve the survival in patients with chemosensitive disease, either in the upfront or salvage setting. Auto-HCT is currently recommended to be used as frontline consolidation in peripheral T cell lymphoma not otherwise specified, angioimmunoblastic T cell lymphoma, anaplastic large cell lymphoma-anaplastic lymphoma kinase negative, NK/T cell (disseminated), and enteropathy-associated T cell lymphoma. However, about one-third of patients never reach transplantation because of early relapse or refractory disease. Allogeneic hematopoietic cell transplantation (allo-HCT), via its immunologic graft-versus-lymphoma effect, has been used to salvage patients with relapsed or refractory disease, resulting in long-term disease-free survival in a fraction of patients. However, the higher risk of transplant-related mortality due to regimen-related toxicities, graft-versus-host disease, and post-transplant infectious complications continues to limit the mainstream adoption of allo-HCT for this disease. Despite that, allo-HCT has been incorporated as part of the frontline treatment for aggressive subtypes of T-NHL, such as γδ T cell lymphoma and aggressive NK cell leukemia. Recent attempts to incorporate novel targeted T cell directed therapies into the treatment pathway of T-NHL may enhance treatment response and enable more patients to reach transplant, offering an alternative means of treating this disease.

Allogeneic Hematopoietic Stem Cell Transplantation in Extranodal Natural Killer/T-cell Lymphoma

Objective

Extranodal NK/T-cell lymphoma (ENKL) is aggressive and resistant to chemotherapy and radiotherapy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for high-risk lymphomas owing to its associated graft-versus-lymphoma (GVL) effect. However, its application to ENKL is limited. We aim to summarize the characteristics of allo-HSCT for ENKL and, more importantly, evaluate whether allo-HSCT could offer any benefits for ENKL.

Materials and Methods

A systematic review and data analysis were performed to evaluate the performance of allo-HSCT in the treatment of ENKL using studies obtained from PubMed, Medline, and Embase from January 2000 to December 2019 in the English language.

Results

A total of 136 cases from 17 eligible publications were included in this study. It was found that after allo-HSCT, with an average follow-up time of 34 months (range: 1-121 months), 37.5% (52) of 136 patients had acute graft-versus-host disease (GVHD) and 31.6% (43) had chronic GVHD. Furthermore, 35.3% (48) of the patients were reported to have relapsed, but 2 of those relapsed only locally and achieved complete remission (CR) again with additional irradiation, chemotherapy, and donor lymphocyte infusions for one and rapid tapering and discontinuation of cyclosporine for the other, earning more than one year of extra survival. Finally, of the 136 patients, 51.5% (70) died because of primary disease progression (42.9%), infection (20.0%), GVHD (11.4%), organ failure (7.1%), hemorrhage (4.3%), and other causes (not specified/unknown) (14.3%).

Conclusion

Allo-HSCT may be a treatment option for advanced or relapsed/refractory ENKL, but its role still requires more rigorous future studies.

Extranodal Natural Killer/T-cell Lymphoma, Nasal Type: Diagnosis and Treatment

The aggressive lymphoma, extranodal natural killer/T-cell lymphoma-nasal type, is strongly associated with Epstein-Barr virus (EBV) and is most common in Asia and in South and Central America. By contrast, incidence is low in the United States and Europe, where extranodal natural killer/T-cell lymphoma represents only 0.2%-0.4% of all newly diagnosed non-Hodgkin lymphomas. At diagnosis, it is important to test for EBV DNA in plasma by polymerase chain reaction and to carry out positron emission tomography/computer tomography and magnetic resonance imaging of the nasopharynx. In stage I/II disease, radiotherapy is the most important treatment modality, but in high-risk stage I/II disease (stage II, age > 60 y, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group performance score ≥2, primary tumor invasion), it should be combined with chemotherapy. The most optimal responses are reached with nonmultidrug resistance-based therapy (eg, asparaginase- or platinum-based therapy). Therapeutic approaches consist of either platinum-based concurrent chemoradiotherapy or sequential chemoradiotherapy. The minimum dose of radiotherapy should be 50-56 Gy. Treatment of stage III/IV disease consists of 3 cycles of chemotherapy followed by autologous hematopoietic cell transplantation. Allogeneic hematopoietic cell transplantation should only be considered in case of relapsed disease or after difficulty reaching complete remission. During treatment and follow-up, plasma EBV levels should be monitored as a marker of tumor load.

Modified SMILE (mSMILE) and intensity-modulated radiotherapy (IMRT) for extranodal NK-T lymphoma nasal type in a single-center population

A modification of the SMILE regimen with dexamethasone, methotrexate, ifosfamide, L-asparaginase, etoposide (mSMILE) followed by Intensity-Modulated Radiotherapy (IMRT) at lower than usual dose, has been adopted as standard of care for extranodal NK-/T-cell lymphoma (ENKL) at our institution. mSMILE is a short course, intensive regimen incorporating pegylated asparaginase. Here, we describe clinical details, outcome and safety of patients receiving mSMILE. Among 28 patients with ENKL treated, response post-mSMILE was 93% (CR 68%), response post IMRT was 95% (CR 87.5%). Among early-stage patients/low PINK-E (n = 13), overall survival (OS) was 100% at the median follow-up of 31 months; progression-free survival (PFS) was 92%. Advanced-stage and intermediate/high PINK-E patients fared similarly (OS 43%, PFS 33.3% at the median follow-up). Thirty-two percent of the patients experienced G3-4 non-hematologic toxicity, all experienced hematologic toxicity. Most localized-stage patients achieved long-term disease control. Despite high response rates, most of the advanced stage patients relapsed quickly.

Extranodal NK/T cell lymphoma

Extranodal natural killer (NK)/T cell lymphoma (ENKTL) is a distinct subtype of Non-Hodgkin’s lymphoma mainly involving the nasal area. Since the entity was first recognized, treatment strategies have been evolving from anthracycline-based chemotherapy and radiotherapy to L-asparaginase containing regimens and recently immune checkpoint inhibitors. With the currently used combined chemotherapy and radiotherapy, more than 70% of patients with localized disease can be cured. L-asparaginase containing regimens have significantly improved treatment outcomes among patients with advanced disease. However, the treatment outcomes of patients with disease refractory to L-asparaginase containing regimens or who experience recurrence remain poor. In this article, we cover the current treatments for ENKTL and emerging treatment approaches.

Pralatrexate as a bridge to allogeneic hematopoietic stem cell transplantation in a patient with advanced-stage extranodal nasal-type natural killer/T cell lymphoma refractory to first-line chemotherapy: a case report

Background

Extranodal natural killer/T cell lymphoma, nasal type, is one of the more common subtypes of mature T cell lymphoma, especially in the Far East Asian population. This aggressive histologic subtype of peripheral T cell lymphomas is frequently susceptible to exposure of Epstein–Barr virus infection. The optimal treatment is not well elucidated. For stage IV disseminated extranodal natural killer/T cell lymphoma, induction chemotherapy with consolidative autologus or allogeneic hematopoietic stem cell transplantation is recommended as the major first-line treatment. However, there is controversy over which type of chemotherapy is most appropriate and effective as a bridge to autologus or allogeneic hematopoietic stem cell transplantation in patients with newly diagnosed disseminated advanced-stage or relapsed extranodal natural killer/T cell lymphoma because of cancer chemoresistance or associated complications. Pralatrexate is the first US Food and Drug Administration-approved novel agent for the treatment of refractory/recurrent peripheral T cell lymphomas. In our case, pralatrexate was used as a successful bridge to allogeneic hematopoietic stem cell transplantation in a patient with advanced-stage disseminated extranodal natural killer/T cell lymphoma refractory to first-line chemotherapy.

Case presentation

We presented a case report of a 29-year-old Asian man diagnosed as having stage IV disseminated extranodal natural killer/T cell lymphoma, nasal type, with skin and bone marrow involvement, whose disease was primary refractory to first-line dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide chemotherapy, but obviously responded to treatment with two cycles of single-agent pralatrexate treatment. Monitoring Epstein–Barr virus viremia revealed dramatic downregulation. In addition to complete remission of the involvement of bone marrow and nasal cavity, skin involvement also obtained partial remission. The extranodal natural killer/T cell lymphoma successfully achieved complete remission after a bridge to allogeneic hematopoietic stem cell transplantation.

Conclusions

This is the first study to present pralatrexate as a successful bridge to allogeneic hematopoietic stem cell transplantation in a 29-year-old Asian male patient with advanced-stage extranodal natural killer/T cell lymphoma refractory to first-line dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide chemotherapy. This case provides a novel treatment opinion for extranodal natural killer/T cell lymphoma, especially for the Far East Asian population.

NK/T-cell lymphomas

NK/T-cell lymphomas are extranodal EBV-related malignancies, mostly of NK-cell and occasionally of T-cell lineage. They are divided into nasal, non-nasal, and disseminated subtypes. Nasal NK/T-cell lymphomas involve the nose, nasopharynx and the upper aerodigestive tract. Non-nasal NK/T-cell lymphomas involve the skin, gastrointestinal tract, testis and other sites. Disseminated NK/T-cell lymphoma involves multiple organs, and may present with a leukemic phase. Initial evaluation requires positron emission tomography computed tomography (PET/CT) and quantification of circulating EBV DNA. Radiotherapy alone is inadequate with frequent relapses. Anthracycline-containing regimens are ineffective. Regimens incorporating asparaginase are currently the standard. For stage I/II disease, combined chemotherapy and radiotherapy is recommended. For stage III/IV disease, asparaginase-containing regimens are needed. Autologous hematopoietic stem cell transplantation (HSCT) is of limited efficacy, whereas allogeneic HSCT may be useful in patients with stage III/IV and relapsed diseases. Immunotherapy with antibodies against CD30, programmed cell death protein 1 and CD38 is promising.

Epstein-Barr Virus-Positive Natural Killer/T-Cell Lymphoma

Extranodal natural killer/T-cell lymphoma, nasal type (ENKL), is a rare malignancy of Non-Hodgkin lymphoma characterized by an aggressive clinical course and poor prognosis. It shows strong association with Epstein-Barr virus infection and occurs more commonly in Asia and Latin America. Various genetic alterations have been identified in ENKL by gene expression profiling and sequencing techniques. The frequent deletion of chromosome 6q21 was reported to lead to the silence of several tumor suppressor genes. Also, there have been novel genetic mutations that were recently uncovered and were found to frequently activate several oncogenic pathways, including the JAK/STAT, NF-κB, and MAPK pathways. Besides, we believe that deregulated single genes and epigenetic dysregulation might be relevant to the mechanism of this disease and thus, may have the potential to shed lights on the development of new therapeutic strategies. The consensus on the standard treatment for ENKL has not yet been currently established. For localized ENKL patients, radiotherapy with concurrent chemotherapy and sequential patterns of chemotherapy and radiotherapy are recommended as first-line therapy. As for advanced or relapsed/refractory ENKL patients, the application of non-anthracycline-containing regimens have significantly improved the clinical outcome, contributing to higher response rate, longer overall survival and progression-free survival. Hematopoietic stem cell transplantation is widely recommended for consolidation after a complete remission or partial remission has been achieved. The anti-programmed death 1 antibody, an immune checkpoint inhibitor, has demonstrated favorable results in treating relapsed or refractory ENKL. Of the current ENKL treatment, researchers are still striving to validate how radiotherapy and chemotherapy should be optimally combined and which of the non-anthracycline-containing regimens is superior. In this review, we summarize the main genetic alterations frequently found in ENKL and their role in providing new insights into the therapeutic targets of this disease, and highlight the recent findings regarding new biologic markers, novel therapeutic strategies applied to this intriguing neoplasm.

Allogeneic Stem Cell Transplantation and Chimeric Antigen Receptor (CAR) T-Cell Therapy for the Treatment of Non-Hodgkin Lymphoma

Despite the myriad of available treatments, a substantial subset of patients with non-Hodgkin lymphoma are not able to achieve a prolonged disease-free interval with conventional chemotherapy or targeted agents. For these patients, hematopoietic stem cell transplantation remains an option for consolidative or curative treatment. Additionally, chimeric antigen receptor T-cell therapy has emerged for patients with relapsed/refractory B-cell lymphomas. Published studies vary widely in their selected approach to transplant and cellular therapies. This review summarizes available data related to allogeneic hematopoietic stem cell transplantation and chimeric antigen receptor T-cell therapy for the treatment of non-Hodgkin lymphomas.

The impact of early diagnosis on the prognosis of extranodal NK/T-cell lymphoma with massive lung involvement: a case report

Background

Pulmonary non-Hodgkin lymphoma (NHL) is rare. The most frequent subtype of pulmonary NHL is low-grade B-cell lymphoma, such as lymphoma of mucosa-associated lymphoma tissue. Extranodal natural killer cell/T-cell lymphoma, nasal type (ENKL) is characterized by predominant extranodal involvement and association with Epstein-Barr virus (EBV). ENKL with massive lung involvement has been infrequently reported, and its prognosis is extremely poor.

Case presentation

A 20-year-old Japanese man presented with intermittent fever lasting for 2 months. Radiological imaging demonstrated multiple nodules of uneven shape and size in both lungs. Video-assisted thoracic surgical lung biopsy showed abnormal lymphocyte infiltration, which was positive for CD3, CD56, and perforin. In situ hybridization for EBV-encoded RNA was positive. From these findings, he was diagnosed with ENKL with lung involvement. The patient was successfully treated with intensive combinational chemotherapy followed by allogeneic cord blood transplantation. He has been alive with continuous complete remission for 1 year after diagnosis.

Conclusions

Although ENKL involving the lung has been reported to have dismal outcomes, our patient showed long-term survival after intensive chemotherapy and up-front allogeneic hematopoietic transplantation. The present case highlights the importance of early diagnosis as well as allogeneic transplantation.

Innovative analysis of predictors for overall survival from systemic non-Hodgkin T cell lymphoma using quantile regression analysis

Background:

Non-Hodgkin T/NK cell lymphoma is a rare and widely variable type of lymphoma with the most dismal prognosis. This study aimed to investigate varied impact of the clinical indicators to the overall survival (OS).

Methods:

We conducted a retrospective study to identify the non-invasive clinical features of T cell lymphoma that can predict prognosis with an innovative analysis method using quantile regression. A total of 183 patients who visited a top-tier hospital in Beijing, China, were enrolled from January 2006 to December 2015. Demographic information and main clinical indicators were collected including age, erythrocyte sedimentation rate (ESR), survival status, and international prognostic index (IPI) score.

Results:

The median age of the patients at diagnosis was 45 years. Approximately 80% of patients were at an advanced stage, and the median survival time after diagnosis was 5.1 months. Multivariable analysis of the prognostic factors for inferior OS associated with advanced clinical staging [HR=3.16, 95%CI (1.39–7.2)], lower platelet count [HR = 2.57, 95%CI (1.57–4.19), P < 0.001] and higher IPI score [HR = 1.29, 95%CI (1.01–1.66), P = 0.043]. Meanwhile, T cell lymphoblastic lymphoma [HR = 0.40, 95%CI (0.20–0.80), P = 0.010], higher white blood cell counts [HR = 0.57, 95%CI (0.34–0.96), P = 0.033], higher serum albumin level [HR = 0.6, 95%CI (0.37–0.97), P = 0.039], and higher ESR [HR = 0.53, 95%CI (0.33–0.87), P = 0.011] were protective factors for OS when stratified by hemophagocytic lymphohistiocytosis (HLH). Multivariable quantile regression between the OS rate and each predictor at quartiles 0.25, 0.5, 0.75, and 0.95 showed that the coefficients of serum β2-microglobulin level and serum ESR were statistically significant in the middle of the coefficient curve (quartile 0.25–0.75). The coefficient of IPI was negatively associated with OS. The coefficients of hematopoietic stem cell transplantation (HSCT) and no clinical symptoms were higher at the middle of the quartile level curve but were not statistically significant.

Conclusions:

The IPI score is a comparatively robust indicator of prognosis at 3 quartiles, and serum ESR is stable at the middle 2 quartiles section when adjusted for HLH. Quantile regression can be used to observe detailed impacts of the predictors on OS.

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.

Allogeneic Stem Cell Transplantation for Patients with Natural Killer/T Cell Lymphoid Malignancy: A Multicenter Analysis Comparing Upfront and Salvage Transplantation

Natural killer (NK)/T cell lymphoid malignancy comprises extranodal NK/T cell lymphoma (ENKTL) and aggressive NK cell leukemia (ANKL), and the outcomes for advanced or relapsed/refractory ENKTL and ANKL remain poor. Allogeneic stem cell transplantation (SCT) can be used as a frontline consolidation treatment to prevent the relapse of advanced disease or as salvage treatment after chemotherapy for relapsed sensitive disease. We retrospectively analyzed 36 patients (ENKTL, n = 26; ANKL, n = 10) who underwent upfront (n = 19) and salvage allogeneic SCT (n = 17) at 6 hospitals. Patients received myeloablative (n = 25) or reduced-intensity (n =11) conditioning regimens depending on the institute's policy. The median age at the time of allogeneic SCT was 37 years (range, 17 to 62), and more patients with ANKL (8/10) received upfront allogeneic SCT than ENKTL patients (11/26). Disease status before allogeneic SCT, conditioning regimen, and donor source did not differ between upfront and salvage allogeneic SCT groups. Febrile neutropenia (n = 20) and acute graft-versus-host disease (n = 16) were common adverse events. The median overall survival (OS) and progression-free survival (PFS) after allogeneic SCT were 11.8 months and 10.0 months, respectively. Twelve patients died from disease relapse and 12 from nondisease-related causes. Ten deaths occurred within 100 days after allogeneic SCT (10/24); these were mostly related to disease relapse (n = 8). The OS after allogeneic SCT did not differ between ENKTL and ANKL (P = .550) or between upfront and salvage SCT (P = .862). Complete chimerism was significantly associated with better PFS (P < .001). No significant differences in PFS were observed based on the conditioning regimen or source of stem cells (P > .05). Allogeneic SCT may be beneficial for patients with ENKTL and ANKL given that some patients were able to maintain their remission after allogeneic SCT. However, allogeneic SCT should only be performed in highly selected patients because the risks of disease relapse and nondisease-related mortality remain high.

Extranodal NK/T-cell lymphoma, nasal type: Clinical features, outcome, and prognostic factors in 101 cases

OBJECTIVES

We aimed to define the clinical features, outcome, and prognostic factors for extranodal NK/T-cell lymphoma (ENKTL) patients in Taiwan.

METHODS

We retrospectively reviewed 101 ENKTL patients diagnosed between February 1998 and October 2015.

RESULTS

The median age of 101 patients was 52 years old (range 22-85); 76.2% of patients were Ann Arbor stage I/II disease. The 5-year progression-free survival (PFS) and overall survival (OS) were 49.9% and 54.8%, respectively. Patients with log[EBV-DNA] ≥ 3.8 and bone marrow hemophagocytosis at diagnosis had inferior PFS and OS. Most stage I/II patients received combined chemoradiotherapy with anthracycline-containing regimen, with overall response rate of 96.7%, complete response rate 86.9%, 5-year PFS 65%, and OS 72%. The relapse rate was 29.3% with a short median disease-free survival of 6.2 months. In advanced stage patients, overall response rate was only 13.6%, with median PFS 2.3 months, and OS 4.8 months. Age ≥ 60 (HR 3.773, 95% CI 1.733-8.215, P = 0.001) and stage III/IV (HR 7.785, 95% CI 2.312-26.213, P = 0.001) were unfavorable prognostic factors for PFS and OS by multivariate analyses.

CONCLUSIONS

Age ≥ 60 and stage III/IV are independent poor prognostic factors for PFS and OS. Early-stage ENKTL patients had good response to combined chemoradiotherapy with anthracycline-containing regimen but with a high relapse rate and short disease-free survival. Anthracycline-containing regimen in advanced stage had poor response and dismal outcome.

Extranodal NK/T-cell lymphoma: Updates in biology and management strategies

Extranodal NK/T-cell lymphoma, nasal type (ENKL), is a rare lymphoma subtype of peripheral T/NK-cell lymphoma that is very common in East Asia and Latin America. Two-thirds of patients have localized disease in the nasal cavity or adjacent sites. Large retrospective studies have revealed the clinicopathologic features of ENKL patients, identified risk factors for short survival time, and developed prognostic models. Next-generation sequencing studies have provided a comprehensive list of recurrent mutations in ENKL. Since the early 2000s, disease-specific therapeutic approaches have been developed, and the standard of care for ENKL has markedly changed. Non-anthracycline-containing chemotherapy with or without radiotherapy is the current standard approach for ENKL treatment. Emerging therapies, including the use of immune checkpoint inhibitors, are being investigated.

Allogeneic hematopoietic stem cell transplantation for T-cell lymphomas

Mature T- and natural killer (NK)-cell neoplasms comprise a group of morphologically, immunophenotypically, molecularly, and clinically heterogeneous disorders with generally unfavorable outcome. Results of first-line chemotherapy are unsatisfactory for the most common T-cell lymphomas (peripheral T-cell lymphoma, not otherwise specified; angioimmunoblastic T-cell lymphoma; anaplastic large cell lymphomas; anaplastic lymphoma tyrosine kinase-negative) as well as for many other entities. High-dose therapy followed by autologous hematopoietic stem cell transplantation (HSCT) is widely recommended for consolidation after a complete or partial remission is achieved. However, about one-third of patients never reach transplantation because of early relapse or refractoriness. Targeted therapies have recently been developed; combinations with chemotherapy may improve outcomes, but long-term results from prospective studies are largely missing. In this situation, allogeneic HSCT remains a valuable treatment option inducing long-lived remissions in about 30% to 50% of patients with relapsed and refractory T-cell lymphoma able to proceed to transplantation. Results of allogeneic transplantation for consolidation in first remission are less defined and its indications remain controversial. With growing evidence that haploidentical HSCT also works in lymphoma, more patients can be brought to transplantation. Decreasing the morbidity and mortality of allogeneic transplantation is a continuous challenge. Integrating new drugs into transplant concepts and setting up prospective studies involving allogeneic transplantation remain unmet needs that warrant urgent study in a group of disorders in which classical chemotherapy and new drugs have generated results, which are far from optimal until today.

Advances in the treatment of extranodal NK/T-cell lymphoma, nasal type

Extranodal natural killer/T-cell lymphoma, nasal type (ENKL) is a subtype of mature T- and natural killer cell lymphomas characterized by its association with Epstein-Barr virus and extranodal involvement. Although there is geographic variance in the frequency of ENKL, its clinical features are similar between Western countries and endemic areas, such as East Asia. Anthracycline-containing chemotherapy is not recommended to treat ENKL. No standard treatment has been established based on the results of randomized controlled trials. In patients with localized disease, radiotherapy is a core component of the recommended first-line therapy. Radiotherapy administered at 50 to 54 Gy, extended involved-site radiotherapy considering tumor invasiveness, and the use of intensity modulated radiation therapy or volumetric modulated arc therapy are associated with efficacy of radiotherapy. Although the use of concurrent chemoradiotherapy has been supported by the results of clinical trials, accumulating evidence supports the use of sequential chemoradiotherapy with non-anthracycline-containing regimens that include l-asparaginase and/or platinum anticancer agents. l-asparaginase-containing chemotherapy is a key component of first-line treatments for systemic ENKL. Hematopoietic stem cell transplantation is recommended as a front-line consolidation therapy for newly diagnosed advanced-stage ENKL. Newer agents including immune checkpoint inhibitors are being investigated for treating ENKL. In this modern ENKL treatment era, multidisciplinary efforts are needed to identify the best timing and sequencing of radiotherapy, l-asparaginase, platinum, newer agents, and hematopoietic stem cell transplantation.

Novel findings from the Asian Lymphoma Study Group: focus on T and NK-cell lymphomas

T and NK-cell lymphomas are aggressive neoplasms with a unique epidemiological distribution, demonstrating higher prevalence in Asian countries compared to the West. Through the efforts of international collaboration, significant progress has been made especially on the biological understanding and clinical management of rare lymphoma subtypes including NK/T-cell lymphomas and monomorphic epitheliotropic intestinal T-cell lymphoma. In this review, we summarize the current status of lymphoma research conducted by the Asian Lymphoma Study Group and highlight key updates on the advancement of T and NK-cell lymphoma research.

Clinical Practice Recommendations on Indication and Timing of Hematopoietic Cell Transplantation in Mature T Cell and NK/T Cell Lymphomas: An International Collaborative Effort on Behalf of the Guidelines Committee of the American Society for Blood and Marrow Transplantation

Recognizing the significant biological and clinical heterogeneity of mature T cell and natural killer (NK)/T cell lymphomas, the American Society for Blood and Marrow Transplantation invited experts to develop clinical practice recommendations related to the role of autologous hematopoietic cell transplantation (auto-HCT) and allogeneic HCT (allo-HCT) for specific histological subtypes. We used the GRADE methodology to aid in moving from evidence to decision making and ultimately to generating final recommendations. Auto-HCT in front-line consolidation is recommended in peripheral T cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase (ALCL-ALK)-negative, NK/T cell (disseminated), enteropathy-associated T cell lymphoma (EATL), and hepatosplenic lymphomas. Auto-HCT in relapsed-sensitive disease is recommended for NK/T cell (localized and disseminated), EATL, subcutaneous panniculitis-like T cell, and ALCL-ALK-positive lymphomas. Auto-HCT is also recommended for PTCL-NOS, AITL, and ALCL-ALK-negative lymphomas if not performed as front-line therapy. Auto-HCT in refractory (primary or relapsed) disease is not recommended for any of the histological subtypes discussed. Allo-HCT in front-line consolidation is recommended for NK/T cell (disseminated), adult T cell leukemia/lymphoma (ATLL; acute and lymphoma type), and hepatosplenic lymphomas. Allo-HCT for relapsed-sensitive disease is recommended for PTCL-NOS, AITL, ALCL-ALK-negative, ALCL-ALK-positive, NK/T cell (localized and disseminated), ATLL (acute, lymphoma type, smoldering/chronic), mycosis fungoides/Sezary syndrome (advanced stage IIB-IVB or tumor stage/extracutaneous), EATL, subcutaneous panniculitis-like T cell, and hepatosplenic lymphoma. Allo-HCT in refractory (primary or relapsed refractory) disease is recommended for any aforementioned histological subtypes. Emerging novel therapies will likely be incorporated into the pretransplantation, peritransplantation, and post-transplantation algorithms (auto-HCT or allo-HCT) with the goals of optimizing efficacy and improving outcomes. We acknowledge that there are unique clinical scenarios not covered by these recommendations that may require individualized decisions.

Management of Advanced and Relapsed/Refractory Extranodal Natural Killer T-Cell Lymphoma: An Analysis of Stem Cell Transplantation and Chemotherapy Outcomes

BACKGROUND

Extra-Nodal natural killer/T-cell lymphoma (ENKL) is a rare lymphoma representing approximately 5-10% of T-cell non-Hodgkin lymphomas diagnosed in the United States each year. Patients with advanced stage III/IV ENKL and relapsed refractory ENKL have a poor prognosis even despite aggressive therapy and stem cell transplantation (SCT). We conducted a review of the management of 37 patients with advanced-stage and relapsed/refractory ENKL in a predominantly non-Asian cohort evaluating both chemotherapy and SCT outcomes.

PATIENTS AND METHODS

We evaluated clinical outcomes in all patients treated for advanced stage III/IV or relapsed/refractory ENKL at MD Anderson cancer center between 2000-2014. Next, we collected stem cell transplant data from four transplant institutions to further evaluate outcomes of both allogeneic (allo-SCT) and autologous (auto-SCT) stem cell transplantation in ENKL.

RESULTS

OS and PFS were 73% and 45% at one year, and 30% and 19% at 3-years, respectively. SMILE chemotherapy was more effective in maintaining a CR compared to CHOP (83% vs 17%). Only achievement of CR was prognostic for OS (HR 0.245, p=0.002) and PFS (HR 0.072, p) CONCLUSION: Our results suggest that achievement of a CR is imperative in patients with advanced ENKL, and is desirable for any patient for whom auto-SCT is utilized. SMILE-based chemotherapy appeared effective in attaining a CR, and was also an effective salvage regimen. For patients attaining a first CR, auto-SCT should be strongly considered, but should definitely be utilized in patients attaining CR2. For patients with refractory disease, allo-SCT can be considered in a selected group of patients.