Purpose: To investigate the impact of prior-to-transplantation azacitidine (AZA) on patient outcome after allogeneic stem-cell transplantation (alloSCT) for myelodysplastic syndrome (MDS).
Patients and methods: Of the 265 consecutive patients who underwent alloSCT for MDS between October 2005 and December 2009, 163 had received cytoreductive treatment prior to transplantation, including induction chemotherapy (ICT) alone (ICT group; n = 98), AZA alone (AZA group; n = 48), or AZA preceded or followed by ICT (AZA-ICT group; n = 17). At diagnosis, 126 patients (77%) had an excess of marrow blasts, and 95 patients (58%) had intermediate-2 or high-risk MDS according to the International Prognostic Scoring System (IPSS). Progression to more advanced disease before alloSCT was recorded in 67 patients. Donors were sibling (n = 75) or HLA-matched unrelated (10/10; n = 88). They received blood (n = 142) or marrow (n = 21) grafts following either myeloablative (n = 33) or reduced intensity (n = 130) conditioning.
Results: With a median follow-up of 38.7 months, 3-year outcomes in the AZA, ICT, and AZA-ICT groups were 55%, 48%, and 32% (P = .07) for overall survival (OS); 42%, 44%, and 29% (P = .14) for event-free survival (EFS); 40%, 37%, and 36% (P = .86) for relapse; and 19%, 20%, and 35% (P = .24) for nonrelapse mortality (NRM), respectively. Multivariate analysis confirmed the absence of statistical differences between the AZA and the ICT groups in terms of OS, EFS, relapse, and NRM.
Conclusion: With the goal of downstaging underlying disease before alloSCT, AZA alone led to outcomes similar to those for standard ICT.