Improved outcome for peripheral blood stem cell transplantation for advanced primary myelodysplastic syndrome.

Stem cell transplantation for myelodysplastic syndrome (MDS) is characterized by high transplant-related mortality (TRM), especially in older patients and those with more advanced disease. Outcome after peripheral blood stem cell transplantation (PBSCT) may be superior to earlier results with bone marrow transplantation. Forty-three patients (aged 12-73 years; median, 49 years) received an HLA-identical sibling donor PBSCT. Twenty three patients aged < or =55 years without prohibitive comorbidity received myeloablative total body irradiation-based conditioning, followed by a T cell-depleted PBSCT and delayed add-back of donor lymphocytes. Older patients or those with comorbidities (n = 20) received reduced-intensity conditioning and an unmanipulated PBSCT. Thirty-seven (86%) had advanced disease (refractory anemia with excess blasts [n = 9], refractory anemia with excess blasts in transformation [n = 6], acute myelogenous leukemia [n = 13], or treatment-related MDS [n = 9]); 6 had low-risk MDS (refractory anemia or refractory anemia with ringed sideroblasts). The median follow-up was 18 months (range, 5-89 months). Actuarial probabilities of 3-year overall survival (OS), disease-free survival, relapse, and TRM were 64%, 59%, 26%, and 23%, respectively, for 34 primary MDS patients. The best results were in 19 patients younger than 50 years of age undergoing myeloablative PBSCT (actuarial probabilities of OS, disease-free survival, relapse, and TRM were 81%, 72%, 22%, and 7%, respectively). Although outcomes for all stages of primary MDS were improved, that for therapy-related MDS remained dismal, with 11% OS, because of a high relapse rate (89%).