All the eligible patients will be treated with ZR-CHOP regimen (Rituximab 375mg/m2 IV d1, cyclophosphamide 750mg/m2 IV d1, epirubicin 70mg/m2 IV d1, vindesine 4mg IV d1，prednison 60mg/m2 d1-5 PO). An interim evaluation will be performed after 4 cycles, the patients who achieve CR or PR will receive another 4 cycles of ZR-CHOP.
The patients with stable disease (SD) or progressed disease (PD) will withdraw from the trial and receive salvage regimens.
During the following-up, surveillance physical examination and CT scans should be performed every 6 months for 2 years to determine the status of disease.
