A Multicenter Retrospective Comparison of Sequential versus Sandwich Chemoradiotherapy for Stage IE-IIE Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

Efficacy of a short sandwich protocol, methotrexate, gemcitabine, L-asparaginase and dexamethasone chemotherapy combined with radiotherapy, in localised newly diagnosed NK/T-cell lymphoma: A French retrospective study

Extranodal NK/T-cell lymphoma, nasal type is a rare and aggressive form of lymphoma, historically associated with poor prognosis. We report here the results of a retrospective multi-centre study evaluating the efficacy of MGAD (methotrexate, gemcitabine, L-asparaginase and dexamethasone) regimen (two cycles) combined with 'sandwich' radiotherapy in 35 patients with localised newly diagnosed extranodal NK/T-cell lymphoma. Thirty-two patients (91%) reached complete remission. With a long median follow-up of 59.6 months, progression-free and overall survival at 2 and 5 years were 71%, 80% and 53%, 73%, respectively. Around one third of the patients experienced relapse within a median time of 14.5 months. Side-effects were manageable with grades 3-4 cytopenias, mucositis and infection in 50%, 24% and 21% of the cases, respectively. Monitoring of asparaginase activity was performed in 13 patients and showed inactivation of the drug in seven (54%) patients. Our results indicate that a short therapy by sandwich MGAD chemoradiotherapy is a tolerable and effective treatment option in localised newly diagnosed extranodal NK/T-cell lymphoma patients.

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.

EBV-associated NK and T-cell lymphoid neoplasms

PURPOSE OF REVIEW

Epstein-Barr virus (EBV)-associated neoplasms derived from natural killer (NK) or T cells comprise a group of clinically and biologically heterogenous disorders affecting children and adults, which are overall rare but more prevalent in Asia and South America. This review focuses on neoplasms presenting in the adulthood, addressing recent genomic discoveries as well as therapeutic developments in these highly aggressive disorders.

RECENT FINDINGS

Distinct molecular subtypes of extranodal NK/T-cell lymphomas (ENKTCLs) have been described, with differences in cell of origin, EBV pattern, genomic alterations, clinical characteristics, response to asparaginase-based therapies and to more recent approaches targeting molecular aberrations of the lymphoma. For the last two decades, progress in the clinical management of ENKTCL was based on L-asapraginase containing combinations and the incoroperation of radiotherapy. A subset of cases with PDL1-2 structural alterations may be more responsive to treatment with immune checkpoint inhibitors. Primary nodal EBV+ lymphomas derived from T or NK cells have distinctive features separating them from both peripheral T-cell lymphoma not otherwise specified and ENKTCL. Treatment algorithms correspond to those for advanced ENKTCL.

SUMMARY

With better understanding of lymphomagenesis, genomic landscape and immunologic aspects of the diseases, future treatment options will include targeted therapies including immune checkpoint inhibitors and novel antibodies.

First-line chemoradiation with or without chidamide (tucidinostat) in patients with early stage intermediate- and high-risk early-stage extranodal nasal-type natural killer/T-cell lymphoma: a randomized phase 2 study in China

PURPOSE

We investigated the safety and efficacy profile of intensity-modulated radiation therapy (IMRT) followed by gemcitabine, dexamethasone, cisplatin (GDP), plus chidamide in the first-line setting for intermediate- and high-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type (ENKTCL).

METHODS

This was an open-label, randomized phase 2 trial performed at two centers in China. Patients were eligible if they were newly-diagnosed with intermediate- and high-risk early-stage ENKTCL with at least one risk factor based on a nomogram-revised risk index:> 60 years old, elevated serum lactate dehydrogenase, invasion of the primary tumor, stage II or Eastern Cooperative Oncology Group performance status > 1 or stage II disease. Patients were treated with IMRT followed by GDP, with or without chidamide, in the first-line setting. Two-year progression-free survival (PFS) comprised the primary endpoint. Toxicities, the 2-year overall survival (OS), and the response rate comprised the secondary endpoints.

RESULTS

Eligible patients (n = 74) were enrolled between May 2015 and December 2019. Among them, 37 patients were treated with IMRT+GDP+chidamide (chidamide group), while 37 cases were treated with IMRT+GDP (control group). Follow-up comprised a median of 43.4 months (range, 1.0-74.6 months). The objective response rate was 86.5% in the chidamide group and 78.4% in the control group (P = 0.359) at the end of treatment completion. The 2-year OS and PFS rates were 89.2% and 75.2% in the chidamide group versus 83.8% (P = 0.388) and 70.2% (P = 0.821) in the control group. The main adverse events were hematological toxicities and mucositis, with similar rates in the two groups (P > 0.05).

CONCLUSIONS

The addition of chidamide to IMRT + GDP as first-line treatment achieved similar treatment outcomes and tolerable toxicities in patients with intermediate- and high-risk ENKTCL.

The optimal timing of radiotherapy in the combination treatment of limited-stage extranodal natural killer/T-cell lymphoma, nasal type: an updated meta-analysis

This study was designed to explore the relative efficacy and toxicity of upfront radiotherapy (RT) and late RT in combination treatments for patients with limited-stage extranodal natural killer/T-cell lymphoma nasal type (LS-ENKTL). We searched for clinical trials in the PubMed database that compared upfront RT with late RT in the combined treatment of patients with LS-ENKTL. We systematically evaluated the differences in survival, treatment response, and treatment-related adverse events (AEs) between these two groups. Ten retrospective studies with a total of 1752 patients were included. Upfront RT significantly prolonged the overall survival (OS) and progression-free survival (PFS) of patients compared to late RT in combination with chemotherapy (CT) (HR = 0.72, 95% CI 0.59-0.88, P = 0.001 for OS; HR = 0.57, 95% CI 0.41-0.79, P = 0.0007 for PFS). The complete remission (CR) rate in the upfront RT group was superior to that in the late RT group (HR = 1.61, 95% CI 1.09-2.37, P = 0.02). Patients experienced similar local recurrence-free survival (LRFS), objective response rates (ORR), and toxicity between these two arms (P > 0.05 for all) in the analysis of each subgroup. The survival benefit of upfront RT was not correlated with the RT dose, concurrent chemoradiotherapy (CCRT) (or not), or the CT regimen (P > 0.05 for all). Without compromises in terms of toxicity, RT dose, and treatment modality, upfront RT can significantly benefit OS, PFS, and CR compared to late RT in combination treatment. These findings verified that the upfront RT regimen is more suitable for patients with LS-ENKTL.

NK-/T-cell lymphomas

Natural killer/T-cell lymphoma (NKTL) is a sub-type of Epstein-Barr virus (EBV)-related non-Hodgkin lymphomas common in Asia and Latin America but rare elsewhere. Its pathogenesis is complex and incompletely understood. Lymphoma cells are transformed from NK- or T-cells, sometimes both. EBV-infection and subsequent genetic alterations in infected cells are central to NKTL development. Hemophagocytic syndrome is a common complication. Accurate staging is important to predict outcomes but there is controversy which system is best. More than two-thirds of NKTL lympohmas are localized at diagnosis, are frequently treated with radiation therapy only and have 5-year survival of about 70 percent. Persons with advanced NKTLs receive radiation therapy synchronously or metachronously with diverse multi-drug chemotherapy typically including L-asparginase with 5-year survival of about 40 percent. Some persons with widespread NKTL receive chemotherapy only. There are few data on safety and efficacy of high-dose therapy and a haematopoietic cell autotransplant. Immune therapies, histone deacetylase (HDAC)-inhibitors and other drugs are in early clinical trials. There are few randomized controlled clinical trials in NKTLs and no therapy strategy is clearly best; more effective therapy(ies) are needed. Some consensus recommendations are not convincingly evidence-based. Mechanisms of multi-drug resistance are considered. We discuss these issues including recent advances in our understanding of and therapy of NKTLs.

What we should know about natural killer/T-cell lymphomas

Natural-killer/T cell lymphoma (NKTCL) is the most common extranodal lymphoma with highly aggressive clinical outcome. System biology techniques provide novel insights into the pathogenesis, risk stratification, and clinical management in NKTCL. Comparative genomic hybridization analysis reveal most frequent deletion of chromosome 6q21. Whole-exome sequencing studies identify recurrent somatic gene mutations, involving RNA helicases, tumor suppressors, JAK-STAT pathway molecules, and epigenetic modifiers. Genome-wide association study reports strongest association of HLA-DPB1 rs9277378 with lymphomagenesis. Alterations of oncogenic signaling pathways as well as epigenetic dysregulation of microRNA and long non-coding RNAs are also observed in NKTCL. Epstein-Barr virus (EBV) is the major etiology of NKTCL and the pathogenic mechanism remains unclear. Different risk stratification models are proposed based on clinical parameters (IPI, PINK, and PINK-E, etc.) or biomarkers (Ki67, C-reactive protein level, and EBV DNA, etc.). Therapeutic strategies vary according to disease stage, including radiotherapy, asparaginase-based chemotherapy, hematopoietic stem-cell transplantation, targeted therapy (immune checkpoints inhibitors, and histone deacetylation inhibitors, etc.). Future investigations will be emphasized on EBV-related pathogenesis of NKTCL, prognostic and therapeutic biomarkers, as well as multi-center clinical trials, so as to optimize personalized treatment of NKTCL in the era of precision medicine.

Treatment of localized extranodal NK/T cell lymphoma, nasal type: a systematic review

Extranodal natural killer/T cell lymphoma (ENKTL), nasal type, presents predominantly as a localized disease involving the nasal cavity and adjacent sites, and the treatment of localized nasal ENKTL is a major issue. However, given its rarity, there is no standard therapy based on randomized controlled trials and therefore a lack of consensus on the treatment of localized nasal ENKTL. Currently recommended treatments are based mainly on the results of phase II studies and retrospective analyses. Because the previous outcomes of anthracycline-containing chemotherapy were poor, non-anthracycline-based chemotherapy regimens, including etoposide and L-asparaginase, have been used mainly for patients with localized nasal ENKTL. Radiotherapy also has been used as a main component of treatment because it can produce a rapid response. Accordingly, the combined approach of non-anthracycline-based chemotherapy with radiotherapy is currently recommended as a first-line treatment for localized nasal ENKTL. This review summarizes the different approaches for the use of non-anthracycline-based chemotherapy with radiotherapy including concurrent, sequential, and sandwich chemoradiotherapy, which have been proposed as a first-line treatment for newly diagnosed patients with localized nasal ENKTL.

The optimal timing of radiotherapy in the combined modality therapy for limited-stage extranodal NK/T cell lymphoma (ENKTL): a systematic review and meta-analysis

The optimal timing and sequencing of radiotherapy (RT) and chemotherapy (CT) in the treatment of limited-stage extranodal NK/T cell lymphoma (LS-ENKTL) has not been elucidated. The aim of this meta-analysis was to evaluate whether the timing of RT in relation to CT affects the survival of patients with LS-ENKTL. We searched Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Clinicaltrials.gov , and relevant meeting abstract databases from inception through April 2018 without age or language restrictions. Studies comparing upfront RT plus CT with induction CT followed by RT in patients with LS-ENTKL were eligible for inclusion. Seven studies with 1593 patients were included, and all were retrospective cohort studies. Compared with induction CT followed by RT, upfront RT significantly improved OS of patients with LS-ENTKL (HR = 0.70, 95%CI 0.55-0.88, P = 0.002), with no evidence of heterogeneity across studies (I² = 0%). In subgroup analyses, the beneficial effect of upfront RT on survival did not differ significantly between subgroups of studies with different types of chemotherapy regimens (anthracycline-based or non-anthracycline-based), the administration of concurrent chemoradiotherapy or not, and different median doses of RT (≥ 45 or < 45 Gy). These results suggest that upfront RT plus CT confers survival advantage over induction CT followed by RT for the treatment of LS-ENTKL, and this survival advantage is not significantly affected by the types of CT regimens or timing of CT. Given the retrospective nature of included studies, these results should be interpreted with caution in clinical practice.