Long-term outcomes of patients treated with an EPOCHL regimen as first-line chemotherapy for newly diagnosed extranodal natural killer/T-cell lymphoma: a retrospective single-center study

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.

First-line non-anthracycline-based chemotherapy for extranodal nasal-type NK/T-cell lymphoma: a retrospective analysis from the CLCG

The present study investigated the survival benefit of non-anthracycline (ANT)-based vs ANT-based regimens in a large-scale, real-world cohort of patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL). Within the China Lymphoma Collaborative Group (CLCG) database (2000-2015), we identified 2560 newly diagnosed patients who received chemotherapy with or without radiotherapy. Propensity score matching (PSM) and multivariable analyses were used to compare overall survival (OS) and progression-free survival (PFS) between the 2 chemotherapy regimens. We explored the survival benefit of non-ANT-based regimens in patients with different treatments in early-stage disease and in risk-stratified subgroups. Non-ANT-based regimens significantly improved survivals compared with ANT-based regimens. The 5-year OS and PFS were 68.9% and 59.5% for non-ANT-based regimens compared with 57.5% and 44.5% for ANT-based regimens in the entire cohort. The clinical advantage of non-ANT-based regimens was substantial across the subgroups examined, regardless of stage and risk-stratified subgroup, and remained significant in early-stage patients who received radiotherapy. The survival benefits of non-ANT-based regimens were consistent after adjustment using multivariable and PSM analyses. These findings provide additional evidence supporting non-ANT-based regimens as a first-line treatment of patients with ENKTCL.

Comparison of chemotherapy with or without asparaginase for extranodal nasal NK/T-cell lymphoma in children and adolescents

PURPOSE

As extranodal natural killer/T-cell lymphoma (ENKTL) occurs rarely in children and adolescents, standardized therapy is yet to be determined. This study aimed to describe the clinical features and determine the optimal chemotherapy regimen for childhood ENKTL.

METHODS

The treatment outcomes of radiotherapy combined with asparaginase-based (P-GEMOX or P-GMED) or asparaginase-absent chemotherapy regimens (CHOP, EPOCH, or NHL-BFM-90/95) in patients aged ≤18 years with newly diagnosed ENKTL from December 2006 to December 2018 were compared.

RESULTS

Among the 34 patients included in the study, 21 had stage I/II disease. The overall response rates of chemotherapy with or without asparaginase were 85.0% and 78.6%, respectively. With a median follow-up of 54 months, the 5-year event-free survival (EFS) rates of patients with stage I/II and III/IV disease were 66.2 ± 11.3% and 26.0 ± 12.8%, respectively (P = .027). In stage III/IV patients treated with asparaginase-based or asparaginase-absent regimens, the 5-year EFS rates were 40.0 ± 17.4% and 0%, respectively (P = .236). The 5-year EFS rates of stage III/IV patients who received or did not receive hematopoietic stem cell transplant were 66.7 ± 27.2% and 11.1 ± 10.5%, respectively (P = .054). In addition, chemotherapy-associated side effects were significantly less in patients treated with asparaginase-based regimens as compared to asparaginase-absent regimens in this cohort.

CONCLUSION

P-GEMOX and P-GMED regimens are effective and safe for treating childhood ENKTL.

LncRNA BCYRN1-induced autophagy enhances asparaginase resistance in extranodal NK/T-cell lymphoma

Background: Asparaginase (ASP) is the cornerstone drug in the treatment of extranodal NK/T-cell lymphoma (ENKTCL), and the mechanisms of resistance to ASP remain largely unknown. Long non-coding RNAs play important roles in chemotherapy resistance in various cancers. However, the expression of BCYRN1 and its role in ENKTCL still remain unidentified.

Methods: Lentivirus-mediated BCYRN1 overexpression and knockdown were performed in SNK-6 cells. Cell autophagy was analyzed by adenovirus expressing GFP-LC3B fusion protein. RNA pull-down and RNA Binding Protein Immunoprecipitation Assay were performed to investigate the relationship between BCYRN1 and p53. Western blot analysis was performed to assess the effect of BCYRN1 on different autophagy pathways. Finally, in vivo xenograft tumor model was constructed to analyze the effect of BCYRN1 on tumor growth and ASP resistance.

Results: BCYRN1 was overexpressed in ENKTCL than normal NK cells, and patients with higher expression had significantly inferior progression-free survival (PFS). The IC50 value of ASP was significantly increased in BCYRN1-overexpressed SNK-6 cells and BCYRN1 overexpression could resist the inhibitory effect of ASP on proliferation. ASP could induce concurrent apoptosis and autophagy in ENKTCL, and the latter process was enhanced by overexpression of BCYRN1, mainly through affecting both PI3K/AKT/mTOR and p53/mTOR pathways. BCYRN1 could induce the degradation of p53 via ubiquitination, thus resulting in enhancement of autophagy and ASP resistance, which could be reversed by drug-induced autophagy inhibition. The effect of BCYRN1 on tumor growth and autophagy were confirmed in vivo xenograft model.

Conclusions: It was found that BCYRN1 was a valuable prognostic biomarker in ENKTCL. BCYRN1 could promote resistance to ASP by inducing autophagy, which could be reversed by inhibition of autophagy. Our findings highlight the feasibility of combining autophagy inhibition and ASP in the treatment of ENKTCL.

A proposal for a prognostic index for non-nasal type natural killer/T cell lymphoma after asparaginase-based treatment

In the era of asparaginase-based therapy for extranodal natural killer/T cell lymphoma (ENKTL), the clinical outcomes of ENKTL have notably improved. However, as a rare subtype of ENKTL, the therapeutic effect and prognostic factors of non-nasal type ENKTL remain unclear. Thus, we performed this study to analyze the clinical characteristics and to establish a prognostic model specifically for the non-nasal disease. We performed a retrospective study of consecutive patients newly diagnosed with non-nasal type ENKTL and mainly received asparaginase-based therapy at Sun Yat-sen University Cancer Center (SYSUCC) between January 2011 and December 2019, to analyze the prognostic factors and to propose a prognostic model. We validated the prognostic model in an independent cohort. In total, 98 non-nasal type ENKTL patients were included in the training cohort. Multivariate analyses showed that prognostic factors for OS were elevated LDH levels, involvement of bone marrow and serum total protein (TP) < 60 g/L. We developed a new prognostic model named the non-nasal type ENKTL prognostic index (NPI) by grouping the prognostic factors: group 1, no risk factors; group 2, one risk factor; and group 3, two or three risk factors, which were associated with 3-year OS rates of 84.1% (95% CI, 70.9-97.2), 46.8% (27.7-65.8), and 14.9% (0-32.9), respectively (P < 0.001). These results were validated and confirmed in an independent cohort. The new model is efficient in distinguishing non-nasal-type ENKTL patients with various outcomes in the contemporary era of asparaginase-based therapy.

Radiotherapy followed by DICEP regimen in treatment of newly diagnosed, stage IE/IIE, extranodal NK/T-cell lymphoma patients

BACKGROUND

The optimal treatment strategies for extranodal natural killer/ T-cell lymphoma (ENKTL) have not been defined. We conducted this prospective, open-label, phase II, single-center study aimed to explore the efficacy and safety of radiotherapy followed by DICEP (Dexamethasone, ifosfamide, cisplatin, etoposide, and pegaspargase) regimen in the treatment of patients with untreated, stage IE/IIE, extranodal NK/T-cell lymphoma.

METHODS

Thirty eligible patients were enrolled in this study, receiving radiotherapy of 50Gy/25fx, and followed by chemotherapy with DICEP regimen for 3 cycles if tolerated. Median follow-up time of this study was 70.8 months. We constructed Kaplan-Meier survival curves for survival analyses.

RESULTS

The most common manifestations at the onset of disease were nasal obstruction (80%), with or without fever, and pharyngalgia (20%). The overall response rate (ORR) was 96.7% (29/30). Four patients (13.3%) had progression of the disease (PD), the estimated 5-year progression-free survival (PFS) rate was 86%. Four patients (13.3%) died of disease, and the estimated 5-year cumulative overall survival (OS) was 87%. The most common hematological toxicity was grade 3 or grade 4 neutropenia, which could be successfully managed via using growth-stimulating factors or dose modifications. Hypoalbuminemia and decreased fibrinogen are the top two nonhematologic toxicities. No treatment-related death occurred in this study.

CONCLUSIONS

Our present study showed that radiotherapy followed by DICEP chemotherapy could be an effective and tolerable treatment modality for newly diagnosed, stage IE/IIE ENKTL patients. Adverse events were predictable and manageable.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01667302. Registered: 1 July 2012.