PEG-ASP+Gemoxd vs. PEG-ASP+CHOP as First-line Chemotherapy to Treatment NK/T-cell Lymphoma With Early Stage

Inclusion Criteria: 1. pathologically confirmed, previously untreated ENKTL with stage I/II (for stage I, the patients should have one of the following risk factors: EBV-DNA \> upper limit of normal, lesions beyond nasal, fever, LDH elevation); 2. age range from 18 to 70 years; 3. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2; 4. at least one measurable lesion; 5. adequate haematologic function (haemoglobin \> 8.0 g/l, absolute neutrophil count \> 1500/ml, platelets \> 75,000/l), 6. adequate hepatic function (total serum bilirubin ≤ 1.5 times the upper limit of normal, alanine aminotransferase and aspartate aminotransferase ≤ 2.5 times the upper limit of normal), 7. Hepatitis B virus carriers should have normal HBV-DNA copies and should use antiviral drugs. For patients with elevated HBV-DNA, should use antiviral drugs until the HBV-DNA decrease to \< the upper limit of normal. 8. adequate renal function (serum creatinine ≤ 1.5 mg/dl, creatinine clearance ≥ 50 ml/min); 9. normal coagulation function and electrocardiogram results. 10. Prior chemotherapy and radiotherapy should have been completed \>4 weeks earlier, 11. willingness to provide written informed consent. Exclusion Criteria: 1. mismatch the inclusion criteria 2. systematic central nervous system involvement, previous or concomitant malignancies and any coexisting medical problems that could cause poor compliance with the study protocol. 3. primary lesion not from the upper respiratory