Pre-transplant cytoreductive therapy can improve overall survival of patients with MDS-AML but not MDS-EB2 receiving HLA-matched sibling donor peripheral blood stem cell transplantation.

: To evaluate whether cytoreductive therapy is needed for myelodysplastic syndromes (MDS) patients with excess blasts type 2 (MDS-EB2) and acute myeloid leukemia derived from MDS (MDS-AML) before HLA-matched sibling donor peripheral blood stem cell transplantation (MSD-PBSCT), we retrospectively analyzed 80 cases of MDS-EB2 and MDS-AML patients who received MSD-PBSCT between February 2006 and December 2019 in our hospital. The 3-years overall survival (OS) rate and disease-free survival (DFS) rate were (59.1±5.8)% and (52.5±5.7)%, respectively. The 3-years non-relapse mortality (NRM) rate and relapse rate (RR) were (22.4±0.2)% and (25.4±0.2)%, respectively. Univariate analysis showed that, hematopoietic cell transplantation comorbidity index (HCT-CI) ≥ 2, poor/very poor karyotype and occurrence of grade III-IV acute graft-versus-host disease (aGVHD) are risk factors for OS. Patients received pre-transplant cytoreductive therapy (PCT) and obtained complete remission (CR) had significantly higher OS rate than those who failed to achieve CR (non-CR group) and those who did not receive PCT (non-PCT group) [(80.0±8.3)% versus (38.1±10.6)% versus (56.1±9.3)%, P=0.010]. PCT significantly increased the OS rate [(62.2±10.0)% versus (20.0±17.9)%, P=0.013] for MDS-AML patients but not for MDS-EB2 patients [(59.2±11.1)% versus (62.9±10.1)%, P=0.991]. Our findings suggest reducing tumor burden by cytoreductive therapy to obtain CR before transplant improves OS. For MDS-AML patients, PCT is beneficial, while for MDS-EB2 patients, PCT is not necessary.