The effects of adding decitabine to conditioning regimen for patients with acute myeloid leukemia or myelodysplastic syndrome undergoing allogeneic hematopoietic stem cell transplantation: a systematic review and meta-analysis

Decitabine shows favorable efficacy in induction and maintenance therapy for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), but its role in pre-transplant conditioning still has not been established. We performed a systematic review and meta-analysis of comparative studies investigating the effects of adding decitabine to conditioning regimens in AML/MDS patients undergoing allogeneic hematopoietic stem cell transplantation. Meta-analysis was conducted with Review Manager 5.4. For time-to-event outcomes, pooled hazard ratios (HRs) were calculated using generic inverse-variance method. For dichotomous data, pooled risk ratios (RRs) were calculated using Mantel-Haenszel method. Fixed-effects model was adopted if there is no significant heterogeneity. Literature search and study selection identify 9 eligible studies, including 2 randomized controlled trials and 7 retrospective comparative studies. Meta-analysis show that addition of decitabine to conditioning regimen is associated with significantly better overall survival (HR 0.61; 95% CI: 0.49-0.76; P < 0.00001), reduced risk of relapse (HR 0.58; 95% CI: 0.46-0.73; P < 0.00001), and better disease-free survival (HR 0.67; 95% CI: 0.55-0.81; P < 0.0001) without increasing non-relapse mortality (HR 0.82; 95% CI: 0.56-1.18; P = 0.28) and grade II-IV acute graft-versus-host disease (RR 0.75; 95% CI: 0.54-1.04; P = 0.08).