University of Maryland, Baltimore, MD; 4 Greenebaum Cancer. Center Blood and Marrow Transplant Unit, University of. Maryland Medical Center, Baltimore, MD.
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Abstracts / Biol Blood Marrow Transplant 22 (2016) S19eS481
has been used as a conditioning regimen throughout. While absence of equipment for total body irradiation in our center was considered a hindrance during these years, increasing evidence suggesting that radiation-free conditioning regimens are equal to radiation-dependent regimes for many indications of hematopoietic stem cell transplantation prompted us to turn this challenge into an advantage. Subjects and Methods Between 1991 and 2012, 1105 transplantations have been performed on fifteen-year-old or younger patients (975 allogeneic and 130 autologous) in our center. Busulfan/cyclophosphamide has been the most conditioning regimen used. Results: Mean of pediatric transplantations per annum was 31.69 before 2007 and 99.67 afterwards and allogeneic transplant accounts for 88.2% of the total. Peripheral blood was the most common source for graft (62.62%) overall. Inherited RBC abnormalities (mainly thalassemia) and leukemias were the leading indications for transplantation in our center. Allogeneic group had better disease-free survival than autologous group (64%, SE: 1.7% versus 51.5%, SE: 5.0%). Overall, our outcomes were comparable to those of other major centers Discussion: Not long ago total body irradiation was considered indispensable in hematopoietic stem cell transplantation; increasing effectiveness of radiation-free conditioning regimens coupled with long-term side-effects of total body irradiation, is already changing the ways in which clinicians prioritize conditioning regimens, particularly in pediatric candidates.
476 Impact of Prior Conditioning Intensity on Outcomes after Relapse Following Allogeneic Hematopoietic Stem Cell Transplantation for AML and MDS: A Single-Center Retrospective Analysis Hannah Kaizer1, Greer Waldrop1, Ashraf Badros 2, Maria Baer 3, Vu Duong 3, Ashkan Emadi 3, Mehmet Kocoglu 2, Mindy Landau 2, Nicolette Maria Minas 2, Aaron Rapoport 2, Kathleen Ruehle 4, Saul Yanovich 2, Jean Yared 2, Nancy Hardy 2. 1 University of Maryland School of Medicine, Baltimore, MD; 2 Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD; 3 Greenebaum Cancer Center, University of Maryland, Baltimore, MD; 4 Greenebaum Cancer Center Blood and Marrow Transplant Unit, University of Maryland Medical Center, Baltimore, MD While relapse is less common after allogeneic hematopoietic stem cell transplantation (SCT) for acute myeloid leukemia and myelodysplastic syndrome (AML/MDS) following myeloablative conditioning (MAC) compared with reduced-intensity conditioning (RIC), MAC has not yielded a clear survival benefit in adults transplanted for AML/MDS. We studied outcomes of all patients with AML/MDS transplanted at our center between 2005 and 2014 who subsequently relapsed. We compared post-relapse survival between patients originally transplanted with MAC (n¼30) with recipients of RIC (n¼31), hypothesizing that relapse treatment outcomes would be better in the latter group.
MAC (N¼30) Cause of death N (%) Alive Disease TRM NTRM (late deaths)
RIC (N¼31)
p-value
Total
0.07 3 (10.0) 17 (56.7) 10 (33.3) 0 (0.0)
6 (19.4) 20 (64.5) 3 (9.7) 2 (6.5)
9 (14.8) 37 (60.7) 13 (21.3) 2 (3.3)
Of 160 SCT recipients, post-transplant AML/MDS relapse occurred in 30 of 84 MAC recipients (35.7%) and 31 of 76 RIC recipients (40.8%, p¼0.5). Median follow-up after relapse was 10.9 months [95% CI: 7.5-14.2 months]. The median time to relapse was 3.03 months [CI: 2.1-3.7 months] after MAC vs. 5.4 months [CI: 3.2-7.7 months] after RIC (p
