Management of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

Extranodal natural killer/T-cell lymphoma, nasal type (NKTL) is an uncommon aggressive subtype of non-Hodgkin lymphoma, which is significantly more common in East Asia and Latin America. Three-quarters of patients present with stage I/II disease, and half of patients have a low-risk International Prognostic Index score. Although additional factors including natural killer/T-cell lymphoma prognostic index and peripheral blood Epstein-Barr virus load influence the outcomes, the modality of treatment largely differs according to stage (based on nonrandomized studies). In early-stage disease, a combination of chemotherapy and involved-field radiotherapy (IFRT) appears to improve outcome compared with chemotherapy alone. Radiotherapy dose > 50 Gy, concurrent or sequential chemoradiation, and early use of IFRT results in better outcomes than doses < 50 Gy and delay in initiation of IFRT. In late-stage NKTL, chemotherapy alone is the mainstay of treatment. Compared with the CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen, newer regimens containing L-asparaginase and gemcitabine result in better outcomes; however, toxicity might be an issue. Stem cell transplant has been used as salvage and consolidation therapy with some benefit, particularly in patients with advanced-stage disease in remission at the time of transplant; however, further confirmatory studies are needed. In the past decade, we have seen a significant growth in our understanding of the disease process and an increase in our armamentarium of effective therapeutics; however, further development of novel therapies and optimal selection of available therapy options via randomized trials are necessary to improve the outcomes of this aggressive lymphoma.