Allogeneic Hematopoietic Stem Cell Transplantation For Acute Myeloblastic Leukemia (Aml) Or Myelodysplastic Syndrome (Mds) In Patients (Pts) Older Than 50 Years: A Retrospective Single Center Study

Abstract Background: Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative treatment in MDS, and also in many cases of AML, 2 diseases where median age is higher than 50 years. Aim: Analyse the outcome of patients older than 50 years who received an allogeneic hematopoietic stem cell transplantation (HSCT) for MDS or AML, in Saint-Louis Hospital from January 1997 to December 2007. Method: 48 patients (pts) aged from 50 to 68 years (median: 56) received an HSCT for MDS (N=28) or AML (N=20) during this period. AML pts had intermediate (n=15) or high risk cytogenetics (n=3). 8 pts had failure to initial induction chemotherapy. FAB classification for MDS was: RAEB (n=8), RAEBt (n=6), secondary AML (n=2) or refractory anemia (n=2). Maximal IPSS score was high, intermediate-2 and intermediate-1 in 11, 14 and 4 pts. Ten pts with MDS received an “AML-like” chemotherapy and 5 received demethylating agents before transplant. 18 of the AML pts were in complete remission (CR) at time of transplant (CR1, n=15; CR2, n=3) and 2 were in relapse at time of HSCT. 10, 9 and 9 patients with MDS had < 5%, 5–10% and > 10% blasts in bone marrow at time of HSCT. Results: 19 patients with AML (95%) and 16 patients with MDS (57%) received a HSCT from an HLA-identical sibling donor. Other pts received a matched unrelated donor. Thirty-two pts, including 9/20 and 23/28 had at least one co-morbidity according to Sorror score. The conditioning regimen was myeloablative (MAC) in 14 pts (29%). Reduced intensity (RIC) was fludarabine based in 34 pts, associated with either 2 Gy TBI (n=25) or chemotherapy (n=9). All pts engrafted. 35 pts had acute graft-versus-host disease (GVHD): grade I in 11, grade II in 18 and grade III in 6. GVHD incidence did not differ between pts who received a MAC or a RIC regimen. Two-year overall survival (OS) was 41% (95% CI: 26–57). OS and relapse-free-survival (RFS) were similar after MAC or RIC regimen (OS: 29% vs 35% and RFS: 29% vs 30%). Short-term non-relapse mortality (NRM) was lower in patients who received a RIC as compared to patients who received a MAC regimen but was similar at long-term (6-month NRM = 21% vs 9% and 12-month NRM = 21 vs 19 %). Patients with AML or MDS had similar OS and RFS (OS: 42 vs 41%; RFS: 37 vs 26% at 2 years for AML and MDS, respectively). NRM was not significantly higher in pts with MDS (26 vs 10% at one year) whereas relapse rate was not significantly higher in pts with AML (13 vs 6%). Conclusion: HSCT for AML or MDS after 50 years is a curative option for pts with related or unrelated HLA-identical donor regardless kind of conditioning regimen and co-morbidity at time of transplantation.