Results of allogeneic stem cell transplantation in the Spanish MDS registry: prognostic factors for low risk patients.

Although new agents have been approved for the treatment of MDS, the only curative approach is allogeneic hematopoietic stem cell transplantation (HSCT) and thus, in particular circumstances this procedure has been proposed as a treatment option for low risk patients. We have retrospectively analyzed the results of HSCT in 291 patients from the Spanish MDS registry with special attention to low risk MDS (LR-MDS) in order to define the variables that could impact their clinical evolution after transplantation. At 2 years OS was 51% and EFS was 50% (95% CI 0.7-4.5 years for OS and 95% CI 0.1-3.9 years for EFS). Among 43 LR-MDS, transplant-related mortality was 28%. At 3 years, OS was 67% (95% CI 264.7-8927.2 days for OS) and EFS was 64% (95% CI 0-9697.2 days for EFS). In the multivariate analysis only cytogenetics retained statistical significant effect on both OS (p=.047) and EFS (p=.046). Conditioning regimen could improve outcome among this subset of patients (OS 86% and RFS 100% for patients receiving RIC regimen). The present study confirms that specific disease characteristic as well as transplant characteristics have a significant impact on transplant outcome. Regarding low risk patients a non-myeloablative conditioning would be preferable especially in cases without high-risk cytogenetics.