The Clinical Features and Survival Outcome of 107 Newly Diagnosed Advanced Stage Extranodal NK/T-Cell Lymphoma Cases: A Triple-Center Study

OBJECTIVE: Advanced stage extranodal natural killer/T-cell lymphoma (ENKTL) is a distinct type of non-Hodgkin lymphoma and the prognosis of ENKTL is poor with current treatment. This study aimed to investigate the clinical features, treatment strategy and survival outcome in patients with advanced stage ENKTL. PATIENTS AND METHODS: A total of 107 patients with newly diagnosed advanced stage ENKTL between January 2010 and December 2014 were reviewed from three cancer centers. Survival probability was calculated using Kaplan-Meier and the survival curves were compared by Log rank test. Cox regression analyses was performed to investigate the prognostic factors in ENKTL. RESULTS: The median patient age in our cohort was 42.0 years, with a male to female ratio of around 2.3:1. Over half of the patients had B symptoms (n = 61), high IPI scores (≥ 2, n = 60) and high Prognostic Index of Natural Killer Lymphoma (PINK) scores (≥ 3, n = 69). Elevated LDH level was present in around half of the patients (44/91). Most patients (n = 88) in our cohort originated in upper aerodigestive tract and the remaining 19 cases presented with non-upper aerodigestive tract involvement at first diagnosis. Chemotherapy regimens used in our study mainly include CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) (n = 26), L-asparaginase (L-asp) containing chemotherapy (GELOXD (gemcitabine, l-asparaginase, oxaliplatin and dexamethasone) and SMILE (L-asparaginase, methotrexate, ifosfamide, etoposide, and dexamethasone)) (n = 66). No significant difference between the baseline clinical characteristics was found between the L-asp and CHOP group. The CR rate after treatment was 39.3% (42/107) for the whole cohort. The 3-year progression-free survival (PFS) and 3-year overall survival (OS) rate was 41.0% and 41.5%, respectively. The 3-year PFS (49.2% vs 26.5%, P = 0.048) and 3-year OS (49.4% vs 26.0%, P = 0.030) was significantly higher in the L-asp group than the CHOP group. Patient CR status and PINK score were proved to be significant independent factors affecting OS and PFS by multivariate analysis. The grade 3/4 hematologic toxicity (P = 0.0003) and non-hematologic toxicity (P = 0.0002) occurred more frequently in the SMILE group than the GELOXD group. CONCLUSION: Our results demonstrated that L-asp containing chemotherapy could provide favorable survival outcomes in patients with advanced stage ENKTL.