To explore the safety, tolerability and clinical effects of decitabine combined with R±DHAP for patients with replase and refractory Diffuse Large B cell lymphoma.

This is a randomized,controlled,prospective,open,multi-center clinical trial,amied to evaluate the safety, tolerability,and efficacy of decitabine combined with R±DHAP in replase and refractory Diffuse Large B cell lymphoma.A total of 60 patients are planned to be enrolled into the study.Patients with diagnosis of replase and refractory Diffuse Large B cell lymphoma will be into two groups,and be treated with decitabine pluse R±DHAP or only R±DHAP,respectively.The primary end points are objective responder rate(ORR) and time to progression(TTP) and the secondary end points include overall survival(OS) and progression free survival(PFS).

Inclusion Criteria:

• age:14-65 years;ECOG rate≤2;expected survival≥3 months
• patients with Diffuse Large B cell lymphoma diagnoesd by histopathology detection;
• patients ever received RCHOP or CHOP chemotherapy but did not receive DHAP
• patients never received radiotherapy
• patients with no chemotherapy contraindications:hemoglobin ≥ 90g/L,absoluate neutrophil count ≥1.5x109/L,blood platelet ≥100x109/L,ALT and AST ≤ 2-fold upper normal limit,serum bilirubin ≤1.5-fold upper normal limit,serum creatinine ≤1.5-fold upper normal limit,serum albumin ≥ 30g/L,normal serofibrinogen;
• at least one measurable nidus;
• no other severe diseases conflict with this project,cardiopulmonary function is basically normal
• the urine or blood pregnancy test of women in childbearing age must be negative in 7 days before follow-up visit;
• applicable for follow-up visit;
• no other antitumor adjoint therapy(including antitumor Chinese medicine,immunotherapy and biotherapy),but double phosphate anti-bone transfer therapy and other symptomatic treatment are acceptable;
• understanding this study and assigning informed consent.

Exclusion Criteria:

• rejecting providing blood preparation;
• allergic to drug in this study and with metabolic block;
• rejecting adopting reliable contraceptive method in pregnancy or lactation period;
• uncontrolled internal medicine disease(including uncontrolled diabetes,severe incompetence cardiac,lung,liver and pancreas）；
• with severe infection;
• with primary or secondary central nervous system tumor invasion;
• with immunotherapy or radiotherapy contraindication;
• ever suffered with malignant tumor;
• having peripheral nervous system disorder or dysphrenia;
• with no legal capacity,medical or ethical reasons affecting research proceeding;
• participating other clinical trials simultaneously;
• adopting other anti-tumor medicine excluding this research;
• the researchers considering it inappropriate to participate in the study.