Outcomes of transplant-eligible patients with myelodysplastic syndrome with excess blasts registered in a prospective observational study: The JALSG-CS11-MDS-SCT

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the sole curative therapy for myelodysplastic syndromes (MDS). However, whether bridging therapy (BRT) including azacitidine (AZA) and combination chemotherapy (CCT) prior to allo-SCT should be performed is unclear. We analyzed BRT and the outcomes of patients with myelodysplastic syndrome with excess blasts (MDS-EB) who were registered in a prospective observational study in order to clarify the optimal allo-SCT strategy for high-risk MDS. A total of 371 patients were included in this study. Among 188 patients (50.7%) who were considered for allo-SCT, 141 actually underwent allo-SCT. Among the patients who underwent allo-SCT, 64 received AZA, 29 received CCT and 26 underwent allo-SCT without BRT as an initial treatment. The multivariate analysis identified BRT as independent factors influencing overall survival (AZA vs. without BRT, hazard ratio [HR] 3.33, 95% confidence interval [95%CI] 1.44–7.70, P = 0.005; CCT vs. without BRT, HR 3.82, 95%CI 1.60–9.14, P = 0.003). In a multivariate analysis, BRT showed an independent association with progression-free survival (AZA vs. without BRT, HR 2.23, 95%CI 1.03–4.83, P = 0.041; CCT vs. without BRT, HR 2.94, 95%CI 1.29–6.69, P = 0.010). Transplant-eligible patients with MDS-EB should undergo upfront allo-SCT without BRT.