Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome and Chronic Myelomonocytic Leukemia In Patients up to Age 75: Comparison of Survival In Patients with An Available Donor Compared to Patients without a Donor

Abstract 2381

Allogeneic hematopoietic cell transplantation (HCT) remains the only curative treatment strategy for patients with Myelodysplastic Syndrome (MDS) or Chronic Myelomonocytic Leukemia (CMML). Recent reduction of the transplant related toxicity has permitted the expansion of empiric age limitations for HCT up to 75 years. There has been limited comparative data on HCT focusing on donor availability in patients with MDS/CMML. Between January 2004 and September 2009, a total of 255 new patients (NP) with a diagnosis of MDS or CMML were evaluated for HCT at Moffitt Cancer Center. This report describes the outcomes of these patients with emphasis on donor availability. Donor Search Results: Of the 255 NP, 58 did not undergo a donor search. Reasons for not proceeding were as follows: Medicare declined coverage due to age >65 (18), waiting as have low risk disease (15), patient declined (6), patient seen as second opinion only (7) and patient was not eligible for HCT (12). These patients were not included in the survival analysis. Of the 197 patients who had a donor search initiated, a sibling (SIB) matched unrelated (MUD) or single HLA antigen/allele mismatch (mMUD) unrelated adult donor was found in 173 patients. A suitable adult donor was not identified in the remaining 24 patients. To mitigate bias due to factors giving a survival advantage to patients who were stable enough to survive the donor and proceed to HCT, the survival analysis included only those patients alive 90 days after the donor search was initiated. We have been able to identify donors within this time frame for 99% of the patients who ever found one, although time to transplant is longer. At the 90 days landmark, there were 164 patient in the Donor cohort, and 19 patients in the No Donor cohort. Donor Cohort: The median age was 56.6 yrs (18.5 – 73.5). Ninety-seven patients (59%) were older than 55 yrs and 26 (16%) were above 65 yrs. At the time of the transplant consult, IPSS risk was Low (10), Int-1 (44), Int-2 (48), High (25), AML (21), CMML (13), or not evaluable (NE) (3). Donors included SIB (60), MUD (75) and mMUD (29). Median follow-up of surviving patients is 27.7months (7.2 – 70.7). No Donor Cohort: Median age was 57.4 yrs (32.6 – 68.1) with 12 patients (63%) older than 55 yrs and 3 (16%) patients older than 65 years of age. IPSS at initiation of the donor search was Int-1 (5), Int-2 (6), High (5), AML (1) and CMML (2). Median follow-up is 9.2 months (1.4 – 61.5). Of the 19 patients with no donor, 3 patients received an umbilical cord blood HCT elsewhere and were analyzed by intent to treat. Outcomes: Patients with a donor had significantly improved overall survival from time of donor search vs. patients with no donor (P=0.007) with 2 year OS of 48% vs. 23%, respectively. Median survival for the donor group was 22.2 months [95% CI 14.7 – 35.7] vs. 10.1 months for those without a donor [95% CI 2.3 – 14.7]. Transplant: Of the 164 patients with a donor, 121 (74%) patients received the planned allogenic transplants. The 2-year overall survival (OS) after transplantation is similar for SIB (51%), MUD (39%) or mMUD (68%) transplant recipients (P=0.4), and also similar by age below or above 55 years (P=0.7). These data demonstrate that most patients with MDS or CMML can have a suitable donor identified and proceed to HCT. Overall survival is significantly improved for those patients who have a suitable sibling or unrelated donor.