Upfront radiation is essential for high-risk early-stage extranodal NK/T-cell lymphoma, nasal type: comparison of two sequential treatment modalities combining radiotherapy and GDP (gemcitabine, dexamethasone, and cisplatin) in the modern era

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.

High-dose extended-field radiotherapy plus chemotherapy improved survival in extranodal NK/T-cell lymphoma in a real-life setting: results from the multicenter T-Cell Brazil Project

Extranodal natural-killer/T-cell lymphoma (ENKTL) is a rare and aggressive Epstein-Barr virus related mature T-cell and natural-killer malignancy. Although highly prevalent in South America, few studies covering data from this geographic location have been published. Therefore, this study aims to report clinical characteristics, prognostic factors, and outcomes in a multicenter cohort of ENKTL patients from Brazil. This retrospective, observational and multicenter study included 98 ENKTL patients treated during two decades in Brazil. Data were extracted from the T-Cell Brazil Project database. In our cohort, 59/98 patients (60.2%) were male, with a median age of 50 years. Sixty-two patients (63.3%) had B-symptoms, 26/98 (26.5%) had Eastern Cooperative Oncology Group scale ≥ 2; 16/98 (16.3%) presented extranasal disease and 34.7% (34/98) were advanced-stage (Ann Arbor/Cotswolds III/IV). The median follow-up for the whole cohort was 49 months, with an estimated 2-year overall survival (OS) and progression-free survival (PFS) of 51.1% and 17.7%, respectively. In early-stage disease (IE/IIE), the median OS was 21.8 months for patients treated with concurrent radiotherapy plus chemotherapy (CCRT-VIPD [etoposide/vp-16, ifosfamide, cisplatin and dexamethasone), 16.2 months for sequential chemoradiotherapy (SCRT) followed by asparaginase-based regimens, and 56.7 months for SCRT followed by CHOP-like (cyclophosphamide, doxorrubicin, vincristine and prednisone) treatments, p = 0.211. CCRT was associated with higher rates of early-mortality, hematological toxicity, and mucositis. Median OS was 8.2 months for patients with advanced-stage disease receiving regimens containing asparaginase compared to 3.2 months for anthracycline-based therapy, p = 0.851. Chemo-radiotherapy (CRT) regimens demonstrated better OS (p = 0.001) and PFS (p = 0.007) than chemotherapy alone. Multivariate analysis revealed anemia, relapsed/refractory (R/R) disease and radiotherapy omission as poor outcome predictors for OS. Lymphopenia and radiotherapy omission adversely affected PFS. Concerning progression of disease within 24-months (POD-24), clinical stage III/IV was a poor outcome predictor. In this real-life Brazilian cohort, ENKTL presented dismal outcomes. Radiation therapy was an independent factor for increased OS and PFS, but CCRT regimens were associated with higher toxicities. Polychemotherapy based on anti-multi drug resistant agents was not associated with survival benefit in either early or advanced-stage disease in our patient cohort.

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.

Comparison analysis of first-line asparaginase- versus non-asparaginase-based regimens for early-stage extranodal NK/T-cell lymphoma

The present study investigated the efficacy and toxicity profile of first-line asparaginase (ASP)-based versus non-ASP-based regimens in treating early-stage extranodal NK/T-cell lymphoma (ENKTCL) in non-anthracycline therapy era. This multi-center, real-world retrospective study consisted 305 newly diagnosed localized ENKTCL patients who were treated with sequential chemoradiation between 2010 and 2020 in China: 190 cases received ASP-based regimens and 115 cases received non-ASP-based regimens. Propensity score matching and multivariable analyses were used to compare survivals and toxicities between the two treatment groups. Non-ASP-based regimens achieved comparable survivals compared with ASP-based regimens in the entire cohort. The 5-year overall survival (OS), progression-free survival (PFS) rates were 84.7% and 73.5% for non-ASP-based regimens, and 87.7% (P=0.464) and 74.6% (P=0.702) for ASP-based regimens. The non-inferior survivals of non-ASP-based regimens were consistent after adjustment using PSM and multivariable analyses. However, survival benefits of ASP varied in different treatment modalities. Among patients receiving sequential chemotherapy and radiation (CT+RT±CT), ASP-based regimens achieved higher complete remission rate (54.3 vs. 34.5%, P=0.047) and more favorable survivals compared with non-ASP-based regimens (5-year OS, 87.0 vs. 69.0%, P=0.028). However, for patients receiving sequential radiation and chemotherapy (RT+CT), non-ASP-based regimens achieved comparable favorable survivals as ASP-based regimens. Besides, liver injury, malnutrition, and coagulative dysfunction were significantly more commonly documented in ASP-based regimens. These findings suggested that ASP was an effective agent in treating ENKTCL, especially among those receiving induction CT and RT. For patients who received upfront RT, non-ASP-based regimens might be a comparably effective and more tolerable treatment option.

First-line LVDP (L-asparaginase, etoposide, dexamethasone, and cisplatin) regimen combined with radiotherapy is effective for early-stage extranodal natural killer/T-cell lymphoma, nasal type

Chemotherapy combined with radiotherapy could reduce the risk of recurrence in early-stage extranodal NK/T lymphoma (ENKTL). However, the optimal combined chemotherapy regimen is still unknown. Our previous study reported that LVDP (L-asparaginase, etoposide, dexamethasone, and cisplatin) combined with radiotherapy was a potentially effective and safe treatment regimen for early-stage ENKTL. This study further validated the efficacy and safety of LVDP chemotherapy combined with radiation for early-stage ENKTL with more patients and longer follow-up. We retrospectively studied 112 patients with early-stage ENKTL from September 2010 to September 2019. All patients received the LVDP regimen, and 101 of them received radiotherapy. The patients' characteristics, treatment responses, survival outcomes, prognostic factors, and toxicities were analyzed. The median follow-up was 60 months (range, 4 to 117). All patients received median 4 cycles of the LVDP chemotherapy. At the end of therapy, the objective response rate and complete response rate were 88.3% and 77.6%, respectively. The 3- and 5-year OS were 79.6% and 73.2%, and the 3- and 5-year PFS were 75.4% and 71.6%, respectively. Among them, the LVDP regimen combined with radiotherapy yielded more favorable treatment outcomes (the 3-year OS and PFS were 83.1% and 80.8%). The most common severe hematologic toxicity was leukopenia (25% grade 3/4), and the most common severe non-hematologic toxicity was increased transaminase (4.5% grade 3/4). No pancreatitis or treatment-related death occurred. The LVDP regimen combined with radiotherapy had a good therapeutic response and long-term survival with tolerable toxicity for patients with early-stage ENKTL.

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.

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.

Extranodal NK/T cell lymphoma, nasal type: An updated overview

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is an aggressive malignancy associated with Epstein-Barr virus infection, with a geographic and racial predilection for some Asian and Latin American countries. ENKTCL-NT manifests as a necrotic process affecting nasal or upper aerodigestive structures and, rarely, extranasal sites such as skin, and the gastrointestinal tract. ENKTCL-NT was characterized by its poor prognosis irrespective of clinical stage and therapy. However, during the last two decades, advances in its clinicopathologic, genetic and molecular characterization have been achieved, as have changes in the chemotherapy regimens that, in combination with radiotherapy, are significantly improving the survival of these patients, especially in initial stages. For these reasons, we present an overview of the historical background of ENKTCL-NT along with an updated review of its potential etiological factors, clinicopathologic and molecular features, as well as its prognostic models, current treatment protocols, and future directions on potential promising therapeutic approaches.

Optimal Courses of Chemotherapy Combined with Radiotherapy for Low-Risk Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type: A Propensity Score Matching Analysis

Purpose

This retrospective study compared effectiveness between ≤4 cycles and ≥5 cycles of L-asparaginase/pegaspargase-based chemoradiation in newly diagnosed low-risk extranodal natural killer/T-cell lymphoma (ENKTL), nasal type classified according to the Prognostic Index of Natural Killer (PINK) lymphoma model.

Patients and Methods

Patients were categorized into ≤4-cycle (2–4 chemotherapy cycles, n = 166) and ≥5-cycle groups (5–6 cycles, n = 86). Propensity score matching analysis was used to reduce potential confounding bias between the two groups. Treatment responses, adverse events, and survival outcomes between the two groups were analyzed.

Results

No matter before or after matching (65 in the ≤4-cycle group, 65 in the ≥5-cycle group), response rates and survival outcomes were similar between the ≤4-cycle and ≥5-cycle groups. Incidences of grade 1–2 anemia and transaminase elevation were higher in the ≥5-cycle group. After matching, for stage IE disease, there were no differences in response rates and survival outcomes between the two groups. For stage IIE disease, the complete response rate was higher in the ≥5-cycle group (72.4% vs 92.6%, p = 0.049), and the 3-year overall survival (65.5% vs 85.2%, p = 0.024) and 3-year progression-free survival (58.6% vs 81.5%, p = 0.027) rates were significantly extended in the ≥5-cycle group.

Conclusion

When chemoradiotherapy strategies with L-asparaginase/pegaspargase-based regimens are applied to modern low-risk ENKTL patients classified according to the PINK model, it may be better to moderately extend chemotherapy courses in patients with stage IIE disease.

Risk-based, response-adapted therapy for early-stage extranodal nasal-type NK/T-cell lymphoma in the modern chemotherapy era: A China Lymphoma Collaborative Group study

We aimed to determine the survival benefits of chemotherapy (CT) added to radiotherapy (RT) in different risk groups of patients with early-stage extranodal nasal-type NK/T-cell lymphoma (ENKTCL), and to investigate the risk of postponing RT based on induction CT responses. A total of 1360 patients who received RT with or without new-regimen CT from 20 institutions were retrospectively reviewed. The patients had received RT alone, RT followed by CT (RT + CT), or CT followed by RT (CT + RT). The patients were stratified into different risk groups using the nomogram-revised risk index (NRI). A comparative study was performed using propensity score-matched (PSM) analysis. Adding new-regimen CT to RT (vs RT alone) significantly improved overall survival (OS, 73.2% vs 60.9%, P < .001) and progression-free survival (PFS, 63.5% vs 54.2%, P < .001) for intermediate-risk/high-risk patients, but not for low-risk patients. For intermediate-risk/high-risk patients, RT + CT and CT + RT resulted in non-significantly different OS (77.7% vs 72.4%; P = .290) and PFS (67.1% vs 63.1%; P = .592). For patients with complete response (CR) after induction CT, initiation of RT within or beyond three cycles of CT resulted in similar OS (78.2% vs 81.7%, P = .915) and PFS (68.2% vs 69.9%, P = .519). For patients without CR, early RT resulted in better PFS (63.4% vs 47.6%, P = .019) than late RT. Risk-based, response-adapted therapy involving early RT combined with CT is a viable, effective strategy for intermediate-risk/high-risk early-stage patients with ENKTCL in the modern treatment era.