A Clinical Trial of Decitabine in Relapse and Refractory Diffuse Large B Cell Lymphoma

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.