L-asparaginase Monotherapy as Salvage Treatment in Patients With NK/T Cell Lymphoma

Inclusion Criteria: * Age range 18-75 years old * Histological confirmed NK/T cell lymphoma with progressive or recurrent disease * ECOG performance status 0-2 * Life expectancy of more than 3 months * Normal laboratory values: hemoglobin \> 80 g/dl, neutrophil \> 2×109/L, platelet \> 100×109/L, serum creatine \< 1.5×upper limitation of normal (ULN), serum bilirubin \< 1.5×ULN, ALT and AST \< 2.5×ULN Exclusion Criteria: * Pregnant or lactating women * Serious uncontrolled diseases and intercurrent infection * The evidence of CNS metastasis * History of other malignancies except cured basal cell carcinoma of skin and carcinoma in-situ of uterine cervix