Long-term outcomes of upfront concurrent chemoradiotherapy followed by P-GDP regimen in newly diagnosed early stage extranodal nasal-type NK/T cell lymphoma: A prospective single-center phase II 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.

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.