Extranodal natural killer/T-cell lymphoma: current concepts in biology and treatment

Abstract

Natural killer/T-cell (NK/T) lymphomas represent a group of rare tumors of NK and NK-T cells. The World Health Organization classifies NK-cell tumors into three types, extranodal NK/T-cell lymphomas (ENKL, nasal and non-nasal), NK-cell leukemias, and a blastic variant (CD4-positive, CD56-positive hematodermic neoplasms). We focus our review to the current concepts in biology and treatment of ENKL. Though considerable advances have been made in our understanding of NK-cell biology, malignant transformation including the role of Epstein–Barr virus, and prognosis, the rare nature of ENKL and its heterogeneity limit the ability to standardize therapy. Radiotherapy is fundamental to treatment of early-stage disease with a role for chemoradiotherapy among high-risk patients. The clinical course of advanced disease is highly aggressive with frequent chemotherapy resistance and a poor prognosis. Therapeutic approaches to advanced-stage or relapsed and refractory disease, including the appropriate sequence of chemotherapy, combined modality therapy, and stem cell transplantation is not well-established. International and multicenter clinical trials are needed for this rare and aggressive disease.

Keywords:

• Natural killer
• T-cell
• lymphoma
• diagnosis
• treatment

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.