The purpose of this study is to evaluate the efficacy and tolerability of L-asparaginase monotherapy as salvage treatment in patients with NK/T cell lymphoma

The prognosis of patients with progressive and recurrent NK/T cell lymphoma is poor partially due to lack of effective treatment. L-asparaginase was reported to be effective in this setting by several case reports. The investigators aim to evaluate the efficacy and toxicity of L-asparaginase monotherapy in a prospective phase II study.

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