Allogeneic haematopoietic cell transplantation for myelodysplastic syndrome: prognostic significance of pretransplant IPSS score and co-morbidity

International Prognostic Scoring System (IPSS) score at diagnosis has been shown to be effective in predicting the outcomes of hematopoietic cell transplantation (HCT) in patients with myelodysplastic syndrome (MDS), but the significance of IPSS score at the time of HCT has not been evaluated. Pretransplant comorbidity was recently shown to be an independent predictor of HCT outcomes in patients with a variety of hematologic diseases. We therefore analyzed the clinical significance of IPSS score at the time of HCT and pre-transplant comorbidity in 68 patients who underwent allogeneic HCT for MDS (n=48) or acute myeloid leukemia evolved from MDS (n=20) between December 1995 and January 2008 at a single institute. Prior to HCT, 23 patients were given chemotherapy and 12 were in complete remission (CR) at the time of HCT. Conditioning regimen was busulfan-cyclophosphamide in 38, busulfanfludarabine in 2, busulfan-fludarabine-ATG in 24, and others in 4. Bone marrow was used for hematopoietic cell grafts in 48 and G-CSF mobilized peripheral blood mononuclear cells in 20. The cumulative incidence of engraftment failure was 12.0% with primary failure in 2 and secondary failure in 6. During a median follow-up period of 41.0 months (range, 3.2 to 132.0 months), 27 patients died and 7 relapsed. Twenty-one deaths were not related to relapse of MDS. The 5-year probabilities of overall survival (OS) and event-free survival (EFS) were 60.0% and 57.4%, respectively, and the 5-year cumulative incidences of non-relapse mortality (NRM) and relapse were 32.7% and 9.9%, respectively. Multivariate analyses demonstrated that IPSS score at the time of HCT and pre-transplant comorbidity were significant independent prognostic factors for OS, EFS, and NRM. Post-transplant outcomes were significantly affected by the presence and severity of acute GVHD, but not by chronic GVHD. Patients who developed grade I or II acute graft-versus-host disease (GVHD) showed superior outcomes, as assessed by OS, EFS, and NRM, compared with patients without acute GVHD or those with grade III or IV acute GVHD. No relapse occurred in patients who developed acute GVHD. In conclusion, IPSS score at the time of HCT and pre-transplant comorbidity may stratify the risk of post-transplant outcomes in MDS. Our results also indicate that graft-versus-MDS effects occur after allogeneic HCT.