Comparison Of HLA-identical Related And Unrelated Donor Hematopoietic Stem Cell Transplantation In Intermediate-and Poor-risk Acute Myeloid Leukemia Patients

Objective:To compare the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from HLA-identical related and unrelated donors in patients with intermediate-to poor-risk acute myeloid leukemia (AML). To discover the relevant factors that influence the prognosis of patients. To define the MRD level related subgroup that benefits from allo-HSCT.Methods:This study collected114consecutive patients with intermediate-to poor-risk acute myeloid leukemia (AML) between January2005and December2012.54patients received HLA-identical related donor allo-HSCT,60patients received unrelated donor allo-HSCT. Participants were followed up until death or December31,2013. Treatment related mortality (TRM), cumulative incidence of relapse, relapse-free survival (RFS) and overall survival (OS) and other data were assessed to evaluate curative effect. Multivariate analyses were conducted to define factors that may affect the prognosis of patients. Differences of curative effect were also compared between each group classified by risk stratification or pre-transplant MRD level.Results:Cumulative incidence of grade II-IVacute GVHD in related donor group and unrelated donor group was13.8%vs40.3%, respectively (P=0.002). Incidence of chronic GVHD and extensive chronic GVHD were29.6%vs49.2%(P=0.037),3.7%vs22.0%(P=0.005), respectively. Cumulative incidence of5-year treatment related mortality(TRM) was4.0±2.8%vs26.0±6.8% (P=0.015), cumulative incidence of relapse at5years was22.3±6.1%vs21.6±6.0%(P=0.989),5-year overall survival (OS) and relapse-free survival (RFS) were80.9±5.4%vs60.5±6.9%(P=0.104),74.4±6.3%vs56.9±7.0%(P=0.127), respectively. Classified by pre-transplant MRD,(1.MRD<0.05%;2.0.05%<MRD<0.5%;3.0.5%<MRD<5%;4. MRD>5%), cumulative incidence of relapse at5years between each group were16.4±10.8%,14.3±5.5%,25.0±6.6%,75.0±21.7%(P=0.016). There were no statistical difference in OS, RFS or relapse rate among groups.Conclusions:These results suggest that unrelated donor hematopoietic stem cell transplantation is comparable to HLA-identical related transplantation, and it can be a candidate donor selection in allo-HSCT. Both risk stratification and pre-transplant MRD level classification can play an important role in guiding the treatment of AML patients and indicating the risk of relapse in AML patients.