Extra-nodal natural killer/T cell lymphoma in elderly patients: the impact of aging on clinical outcomes and treatment tolerability.

Extra-nodal natural killer/T cell lymphoma (ENKTL) is rare in elderly patients, and its clinical course is unclear. The efficacy and tolerability of non-anthracycline-based treatments as a standard regimen in elderly patients have not been fully investigated. This study assessed the impact of aging on clinical outcomes and treatment tolerability. We retrospectively analyzed 51 patients aged ≥60 years who were diagnosed with ENKTL from January 1998 to December 2012. We defined new treatments as non-anthracycline regimens (etoposide, ifosfamide, mesna, cisplatin, and dexamethasone (VIPD); etoposide, ifosfamide, mesna, dexamethasone, and L-asparaginase (VIDL); methotrexate, leucovorin, etoposide, ifosfamide, mesna, dexamethasone, and L-asparaginase (MIDLE); ifosfamide, methotrexate, etoposide, and prednisolone (IMVP16/PD); or methotrexate, leucovorin, etoposide, ifosfamide, mesna, dexamethasone, and L-asparaginase (SMILE), with or without radiation therapy). The median age was 66 years (60-83 years). Twenty patients were diagnosed at advanced stage, and 18 had poor performance status. The overall survival and progression-free survival were 6.7 and 5.2 months, respectively. Clinical outcomes of patients with early disease were superior to those of patients with advanced disease. Among patients who received new treatments, concurrent chemoradiation therapy (CCRT) for localized disease was tolerable, although 37.5 % of patients with advanced disease who received SMILE discontinued chemotherapy due to intolerability. Elderly patients with ENKTL have poor prognostic factors compared to younger patients. In particular, patients with advanced disease have extremely poor prognosis due to inability to tolerate treatment and rapid progression of disease.