Current treatment approaches for NK/T-cell lymphoma.

Extranodal NK/T-cell lymphoma, nasal type (ENKL), is a form of lymphoma characterized by preferential extranodal involvement, Epstein-Barr virus (EBV) association, and geographic diversity in incidence. ENKL tumor cells express P-glycoprotein, which is related to multidrug resistance (MDR). This MDR phenomenon is thought to be the major reason why ENKL is resistant to anthracycline-containing chemotherapies and has led researchers to explore novel therapeutic strategies. Since the early 2000s, next-generation therapies, including upfront radiotherapy, chemotherapy, or concurrent chemoradiotherapy using non-MDR-related drugs, have markedly changed the management of ENKL. However, a recent large retrospective study in Japan revealed several limitations of next-generation therapies, in particular that they resulted in almost no improvement of early disease progression. This review will summarize the current management of ENKL, primarily based on clinical trial results, and provide clues for better future management.