Umbilical Cord Blood As an Alternate Donor Source for High Risk Elderly Patients Undergoing Allogeneic Stem Cell Transplantation for Hematological Malignancies

Allogeneic stem cell transplantation (alloHCT) remains the only curative option for a variety of hematological malignancies. AlloHCT is being increasingly offered in elderly patients with acceptable transplant related mortality. Umbilical cord blood (UCB) is established as an alternate donor source however some are reluctant to consider its use in elderly patients due to anticipated morbidity. We evaluated outcomes in alternate donor sources, prior to the initiation of haploidentical transplantation at our institution, of matched unrelated donor (MUD) and UCB in elderly patients (median age 64, range 60-74) from 2005-2015. One hundred and eighty four patients were included (MRD: 57; MUD: 69; UCB: 58). Eighty seven underwent myeloablative conditioning (52.7%). There was no difference in acute (aGVHD) or chronic graft versus host disease (cGVHD) between donor sources. ATG was protective for grade III-IV aGVHD (p=0.0498) and high disease risk index per Armand et al predictive of cGVHD (p=0.0496). UCB engraftment was longer for both neutrophils (p=0.005) and platelets (p 2) comorbidity index (42%) per Sorror et al. There was a trend toward inferior progression free survival (PFS) amongst both UCB (5.50 months; 95% CI 2.83—9.36) and MUD (5.59 months; 95% CI 3.68-17.68) as compared to MRD (18.3 months; 95% CI 8.38-64.79)(Table 1). Compared to MRD, UCB experienced inferior median overall survival (OS) HR 1.877 (95% CI 1.160-3.037) but no difference was seen between UCB and MUD or MUD and MRD in multivariable analysis (Table 1 and 2). The leading cause of death in UCB recipients was infections (40%) followed by relapse (17%). Our experience shows that even in this very high risk elderly cohort, UCB continues to be a viable alternate donor source. Methods to reduce late infectious complications are needed such as new approaches to accelerate T cell engraftment which is currently being explored at our center.