Extranodal natural killer/T-cell lymphoma: current concepts in biology and treatment.
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.
Kohrt
Holbrook
H
Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
Advani
Ranjana
R
D003131:Combined Modality Therapy; D004358:Drug Therapy; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D054391:Lymphoma, Extranodal NK-T-Cell / Q000473:pathology* / Q000628:therapy*; D009367:Neoplasm Staging; D011379:Prognosis; D011878:Radiotherapy; D016019:Survival Analysis