Treatments and Outcomes of Patients With Extranodal Natural Killer/T-Cell Lymphoma Diagnosed Between 2000 and 2013: A Cooperative Study in Japan

PurposeTo elucidate the management and outcomes of patients with extranodal natural killer/T-cell lymphoma, nasal type (ENKL), who were diagnosed between 2000 and 2013 in Japan.Patients and MethodsData from 358 patients with ENKL diagnosed between 2000 and 2013 from 31 institutes were retrospectively analyzed.ResultsPatients’ median age was 58 years, and 257 (72%) had localized disease. The most common first-line treatment was radiotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin (RT-DeVIC) (66%) for localized ENKL and L-asparaginase–containing chemotherapy (30%) for advanced ENKL. With a median follow-up of 5.8 years, overall survival (OS) rates at 5 years for localized and advanced ENKL were 68% and 24%, respectively. The prognostic index of natural killer lymphoma was validated in our study, although only 4% of patients with localized ENKL were classified as high risk. With a median follow-up of 5.6 years, OS and progression-free survival at 5 years in the 150 patients who received RT...