[The effects of sequence of radiotherapy and chemotherapy on prognosis of patients with early-stage extranodal NK/T cell lymphoma (nasal type) and its individualized application].

Objective: To analyze the effects of the sequence of radiotherapy and chemotherapy on the efficacy of early-stage extranodal NK/T-cell lymphoma (nasal type, ENKTCL) patients, and to provide a quantitative evaluation method for individualized radiotherapy and chemotherapy. Methods: The Chinese Lymphoma Collaborative Group (CLCG) collected the clinical data of 2 008 patients with early-stage Ⅰ/Ⅱ ENKTCL who received radiotherapy and chemotherapy from January 2000 to early September 2019 from 21 hospitals across the country, including 1 417 males and 591 females, aged 2 to 83 (42±14) years. According to the sequence of radiotherapy and chemotherapy, patients were divided into radiotherapy-first group (388 cases) and chemotherapy-first group (1 620 cases). Survival rate was estimated using Kaplan-Meier method, and multivariate Cox proportional risk model was used to screen and identify independent prognostic factors. The prognostic prediction models of the two therapies were constructed separately, and the models were used to predict the individualized mortality risk of all patients to determine the appropriate radiotherapy and chemotherapy regimen for each patient. Results: The 5-year overall survival rate was 74.2% (95%CI: 69.6%-79.2%) in the radiotherapy-first group and 69.7% (95%CI: 67.1%-72.4%) in the chemotherapy-first group. Although the 5-year overall survival rate of patients in the radiotherapy-first group was numerically higher than that of the chemotherapy-first group, the difference was not statistically significant (χ2= 2.26, HR=0.84 (95%CI: 0.68-1.05), P=0.133). Six variables including age, gender, ECOG score, LDH, Ann Arbor staging, and PTI (primary tumor invasion) were screened out as independent prognostic factors (the chemotherapy-first group: HR were 1.01, 1.25, 2.07, 0.77, 1.34, 1.49, respectively, all P<0.05; radiotherapy-first group: HR were 1.02, 1.31, 1.66, 0.78, 1.37, 1.29, all P>0.05). The mean 5-year predicted mortality risk for all patients receiving radiotherapy-first regimen was lower than those receiving chemotherapy-first regimen (26.8% vs 30.2%, P<0.001). There were individualized differences in the predicted mortality risk of patients with different clinical characteristics who received radiotherapy-first regimen or chemotherapy-first regimen. Conclusion: Patients with stage Ⅰ/Ⅱ ENKTCL treated with radiotherapy-first regimen had a better expected prognosis than patients treated with chemotherapy-first regimen. The quantitative assessment of the differential effects of the sequence of radiotherapy and chemotherapy on the mortality risk of individual patients based on their clinical characteristics was helpful for the clinical development of the optimal radiotherapy and chemotherapy plan for each patient.

[Outcome of radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type].

Objective: To evaluate the prognosis and determine the failure patterns after radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL). Methods: A total of 557 patients from 2000-2015 with low-risk early-stage ENKTCL who received radiotherapy (RT) with or without chemotherapy (CT) from China Lymphoma Collaborative Group were retrospectively reviewed. Among them, 427 patients received combined modality therapy, whereas 130 patients received RT alone. Survivals were calculated by Kaplan-Meier method and compared with Log-rank test. Overall survival (OS) was compared with age and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Cox stepwise regression model was used for multivariate analysis. Results: The 5-year OS and progression-free survival (PFS) were 87.2% and 77.2%. The SMR was 3.59 (P<0.001) at 1 year after treatment, whereas it was 1.50 at 4 years after treatment, without significant difference between ENKTCL group and country-matched general population (P=0.146). Compared with RT alone, CMT did not result in significantly superior 5-year OS (87.0% vs 87.4%, P=0.961) or PFS (76.1% vs 80.7%, P=0.129). Local failure (11.5%, 64/557) and distant failure (10.8%, 60/557) were the main failure modes, while regional failure was rare (2.9%, 16/557). The 5-year locoregional control rate (LRC) was 87.2% for the whole group, with 89.5% for ≥50 Gy versus 73.7% for <50 Gy (P<0.001). Radiotherapy dose was an independent factor affecting LRC(P<0.05). Conclusions: Radiotherapy achieves a favorable prognosis in patients with low-risk early-stage ENKTCL. The incidence of either locoregional or distant failure is low. Radiation dose still is an important prognostic factor for LRC.

Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study.

BACKGROUND: This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL). PATIENTS AND METHODS: We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses. RESULTS: ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results. CONCLUSIONS: The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.

[Clinical features and treatment outcome of extranodal nasal-type NK/T-cell lymphoma of the extra-upper aerodigestive tract].

Objective: To investigate the clinical features and prognosis of extranodal nasal-type NK/T-cell lymphoma of the extra-upper aerodigestive tract (extra-UADT NKTCL). Methods: The clinical data of 159 patients with extra-UADT NKTCL from the China Lymphoma Collaborative Group (CLCG) database between November 2001 and December 2015 were retrospectively analyzed. Kaplan-Meier survival analysis and Log-rank test were used to evaluate the prognosis. The Cox regression model is used for multi-factor analysis. Results: Extra-UADT NKTCL commonly occurs in skin and soft tissues (106/159, 66.7%) and gastrointestinal tract (31/159, 19.5%). The incidences of elevated lactate dehydrogenase (LDH) and Ann Arbor Ⅲ~Ⅳ stage were 47.8% (76/159) and 64.2% (102/159), respectively. The 3-year overall survival (OS) and progression-free survival (PFS) rates were 43.6% and 27.9%, respectively. The corresponding OS rates of primary skin/soft tissue site and gastrointestinal tract site were 41.0% and 59.4% (P=0.281), while the PFS rates were 24.8% and 48.3%, respectively (P=0.109). Combined modality treatment improved the 3-year OS of all the patients (58.4% vs 33.9%, P=0.001) and 3-year PFS (40.7% vs 20.7%, P=0.008) when compared with chemotherapy alone. LDH elevation, Ann Arbor synthesising and ≥2 junction external bits were intrusive as independent risk factors for total survival (P<0.05), LDH elevation and ≥2 junction outer bits were intrusive as independent risk factors for progressionless survival(P<0.05). The distant extranodal dissemination was the primary failure patterns. Conclusions: Extra-UADT NKTCL appears to have distinct clinical characteristics and poor outcome. Compared with chemotherapy alone, combined modality treatment may improve the prognosis of patients with extra-UADT NKTCL.

Prognostic nomogram for overall survival in previously untreated patients with extranodal NK/T-cell lymphoma, nasal-type: a multicenter study.

The aim of this study was to develop a widely accepted prognostic nomogram for extranodal NK/T-cell lymphoma, nasal-type (NKTCL). The clinical data from 1383 patients with NKTCL treated at 10 participating institutions between 2000 and 2011 were reviewed. A nomogram was developed that predicted overall survival (OS) based on the Cox proportional hazards model. To contrast the utility of the nomogram against the widely used Ann Arbor staging system, the International Prognostic Index (IPI) and the Korean Prognostic Index (KPI), we used the concordance index (C-index) and a calibration curve to determine its predictive and discriminatory capacity. The 5-year OS rate was 60.3% for the entire group. The nomogram included five important variables based on a multivariate analysis of the primary cohort: stage; age; Eastern Cooperative Oncology Group performance status; lactate dehydrogenase; and primary tumor invasion. The calibration curve showed that the nomogram was able to predict 5-year OS accurately. The C-index of the nomogram for OS prediction was 0.72 for both cohorts, which was superior to the predictive power (range, 0.56-0.64) of the Ann Arbor stage, IPI and KPI in the primary and validation cohorts. The proposed nomogram provides an individualized risk estimate of OS in patients with NKTCL.