MEDA Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation for Stage IV Natural Killer/T-cell Lymphoma

Inclusion Criteria: Pathological diagnosis of extranodal natural killer/T-cell lymphoma, nasal type based on WHO 2008 classification of tumors of haematopoietic and lymphoid tissue. Eastern Cooperative Oncology Group (ECOG ) performance status 0\~3. Stage IV disease with at least one measurable lesion. Preserved organ functions for: Platelet\>50×10\*9/L, hemoglobin\>80g/L, total bilirubin (TBIL)\<3×ULN, alanine transaminase (ALT)\<5×ULN, serum creatinine (Cr)\<1.5×ULN, fibrinogen≥0.5g/L, LVEF≥50%. Signed Informed consented. Exclusion Criteria: Relapsed or progressive disease to prior L-asparaginase-based chemotherapy. Concurrent cancers need surgery or chemotherapy within 6 months. History of chemotherapy or radiotherapy for other solid cancers within 3 years. Recent history of radiotherapy of upper-aero-digestive tract within last 3 months. Significant complications: LVEF≤50%, coagulopathy, autoimmune disease, severe infection, or liver cirrhosis, severe hemophagocytic lymphohistiocytosis. Mental disorders. Pregnant or lactation. HIV, hepatitis virus C (HCV), or active hepatitis virus B (HBV) infection with HBV DNA≥10\*5 copies/ml. History of pancreatitis. Known history for grade 3/4 allergy to the drugs in chemotherapy regimen. Enrolled in other trial treatment.