Reduced intensity conditioning of allogeneic hematopoietic stem cell transplantation for myelodysplastic syndrome and acute myeloid leukemia in patients older than 50 years of age: a systematic review and meta-analysis

Abstract

A systematic review and meta-analysis were performed to explore the efficacy and safety of allogeneic hematopoietic stem cell transplantation with a reduced intensity conditioning regimen in elderly patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Overall survival (OS) and event-free survival (EFS) were established as the primary endpoints for directly assessing the efficacy, and non-relapse mortality (NRM) for safety. The eligible patients were at or above 50years of age, and the outcomes of the typical elderly patients (≥60years) were analyzed individually. The pooled estimates (95% confidence interval (CI)) for 1-year OS, EFS and NRM were 65 (55-74) %, 50 (44-55) % and 26 (21-30) %, respectively; as for the patients≥60years of age, these were 63 (53-72) %, 46 (41-50) % and 28 (23-32) %, respectively. No significantly statistical difference achieved between MDS and AML patients in 1-year EFS and NRM [relative risk (RR) 0.91, 95% CI 0.80-1.04; P=0.172 and RR 1.18, 95% CI 0.82-1.69; P=0.365]. The patients with lower diseases risk had the possibility of higher OS rate at≥3years than those with higher diseases risk (RR 1.37, 95% CI 0.95-1.97; P=0.088). The patients had significantly higher 2-year OS and EFS rates in complete remission (CR, CR1 and CR2) at transplantation compared to those with advanced diseases (P<0.05). RIC-alloHSCT is a feasible treatment option for the patients older than 50year of age with MDS and AML. Advanced diseases status and higher diseases risk may be the poor factors for prognosis.