Upfront transplantation may have better outcomes than pretransplant cytoreductive therapy for treating patients with MDS-EB-1 or MDS-EB-2

Whether patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) benefit from pretransplant cytoreductive therapy remains controversial. Our study compared the outcomes of upfront transplantation with those of pretransplant cytoreductive therapy in the patients who received transplantation and those who dropped out due to cytoreductive therapy-related adverse effects. Patients with MDS-EB-1 or MDS-EB-2 were enrolled and divided into three groups based on therapy pretransplantation: upfront transplantation (upfront, n = 54), induction chemotherapy (CT, n = 66) and hypomethylating agents (HMA, n = 37) alone. One hundred fifty-seven patients were enrolled and 124 received allo-HSCT, with 5.6%, 28.8% and 29.7% of drop-out rate of transplantation in upfront, CT and HMA groups (P = .030), respectively. Overall therapy-related mortality (TRM), cytoreductive therapy and transplant-related mortality was 13.0%, 32.4% and 28.4% (P = .028), and 5-year overall survival (OS) was 73.6%, 43.4% and 46.9% (P = .033). Multivariate analysis showed that CT and HMA were risk factors for TRM and OS, and transplantation was a protective factor for OS. In transplant patients, 3-year cumulative incidence of relapse was 10.6%, 20.4% and 20.3% (P = .033), 5-year TRM was 14.5%, 20.0% and 17.6% (P = .651), OS was 77.3%, 64.3% and 68.8% (P = .047) and DFS was 74.0%, 63.0% and 65.8% (P = .042). Multivariate analysis showed that CT was a risk factor for DFS, while CT, HMA and poor karyotype were risk factors for relapse. Results suggested that pretransplant cytoreductive therapy was not associated with better outcomes in the patients who had undergone transplantation. Therefore, upfront transplantation may be preferable for MDS patients.