Allogenic (Allo) Stem Cell Transplant (SCT) in Patients over Age 70 Years: A Single Center's Experience

TITLE: Allogenic (Allo) Stem Cell Transplant (SCT) in Patients over Age 70 Years: A Single Center's Experience

BACKGROUND: Allo SCT can be curative in patients with hematologic malignancies. However, its utilization in the elderly population has been limited because of concerns of mortality associated with it.

METHODS: We retrospectively analyzed the outcomes of all patients over age 70 years who underwent Allo- SCT at UMass Medical Center since 2010.

RESULTS: 18 patients (12 males; 6 females) were identified from the database. Median age was 72.5 years (range 70 – 84). Six (33%) were over age 75 years. Median hematopoietic stem cell transplant co-morbidity index was 4 (range 0 - 9). Diagnoses were acute myeloid leukemia (n=10), myelodysplastic/myeloproliferative syndromes/ (n=7), chronic lymphoblastic leukemia (n=1). Eight (44%) of the patients had persistent disease at the time of transplant. Median time from diagnosis to transplant was 208.5 days (77.0 – 3959.0). All patients received stem cells from an unrelated donor with the source being peripheral blood (n=14), cord blood (CB) (n=3) and bone marrow (n=1). Preparative regimens were reduced intensity (RIC) (n=17) and ablative (n=1). CB transplant regimen consisted of Thiotepa (5-10 mg/kg), Fludarabine (Flu), and Melphalan (100-140mg/kg). RIC regimen included Flu, and Busulfan (Bu) (3.2mg/kg x2). One patient received myeloablative regimen: Flu and Bu (3.2mg/kg x 3). HLA match was 4/6 for CB recipients and 10/10 for unrelated donor recipients. Graft-versus-host disease (GvHD) prophylaxis was calcineurin inhibitor/mycophenolate mofetil (MMF) (n=15); Sirolimus /MMF) (n=2) and Sirolimus with post transplant cyclophosphamide (n=1).  Seventeen (94%) patients also received peri-transplant antithymocyte globulin. Median CD34 dose infused was 5.0x10e6/kg (range 0.03 – 6.00). Median time to neutrophil engraftment was 17 days (range 13 – 30). Median time to platelet engraftment was 15 days (range 0 – 56). Median length of hospitalization was 19.5 days (range 13 – 49).  The 100-day and 1-year non-relapse mortality (NRM) were 16.7% (CI 4.4 – 51.8%) and 35.2% (CI 14.9 – 69.0%) respectively. Cumulative incidence of acute GvHD at day 100 was 36.4%. For patients surviving beyond 6 months (n= 9), cumulative incidence of chronic GvHD was 44.4%. There was no acute or chronic GvHD in the three CB transplant recipients. Median follow-up of surviving patients was 477.0 days (21 – 1288). Kaplan Meier estimate of one and two year overall survival rate was 54.2% (CI 25.0-76.2%)

CONCLUSION: Allo-SCT can be safely performed in selected patients over age 70.