Trial of R-GemOx Regimen in Previously Untreated Elderly Patients With DLBCL.

Inclusion criteria: 1. Histologically confirmed CD20-positive DLBCL (The germinal center B-cell like (GCB) / non-GCB subtype was determined by immunohistochemistry in paraffin-embedded tissue using CD10, BCL6 and MUM1 protein markers based on Hans's algorithm); 2. New-diagnosed and untreated; 3. Age older than 70 years or older than 60 years with ECOG PS ≥2; 4. Understand and voluntarily sign an informed consent form, able to adhere to the study visit schedule and other protocol requirements. Exclusion Criteria: 1. Poor hepatic or renal function, defined as total serum bilirubin, transaminases or creatinine over two times of the upper limit of normal concentration; 2. Poor cardiac function greater than Grade II according to New York Heart Association Functional Classification; 3. Presence of Grade III nervous toxicity over two weeks; 4. Hepatitis B virus (HBV) load (HBV DNA) more than 1×105 copies/ml; 5. Concomitant malignancy other than DLBCL requiring treatment; 6. Concomitant with other hematologic diseases (such as leukemia, hemophilia, primary myelofibrosis) which is unsuitable to be enrolled into this clinical trial; 7. Contraindication to any drug in this regimen; 8. Active and severe infectious diseases, such as severe pheumonia or septicaemia; 9. Major surgery within three weeks; 10. Any medical, psychological or social conditions which might interfere with the investigators' assessment 11. In any conditions which investigator considered ineligible for this study.