Prognostic Value of the Hematopoietic Cell Transplantation Comorbidity Index for Patients Undergoing Reduced-Intensity Conditioning Cord Blood Transplantation

The Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) has been validated as a tool for evaluating the risk of treatment-related mortality (TRM) in HLA-matched sibling and matched unrelated donor bone marrow and peripheral blood stem cell transplantation patients. However, the role of the HCT-CI after cord blood transplantation (CBT) has not been fully investigated. In this analysis, we sought to evaluate the predictive value of the HCT-CI in patients undergoing reduced-intensity conditioning (RIC) CBT. Between 2006 and 2013, HCT-CI scores were prospectively tabulated for patients with hematologic malignancies sequentially enrolled on multicenter RIC CBT studies coordinated by the Fred Hutchinson Cancer Research Center: 151 patients with acute myeloid leukemia/myelodysplastic syndrome (n = 101), chronic myeloid leukemia (n = 3), acute lymphocytic leukemia (n = 24), non-Hodgkin lymphoma (n = 8), Hodgkin lymphoma (n = 3), and other hematologic malignancies (n = 12) underwent RIC CBT and were included. Two patients received a single CBT and the remaining 149 received a double CBT. All patients received cyclosporine and mycophenolate mofetil for graft-versus-host disease prophylaxis. Median HCT-CI for the whole group was 3 (range, 0 to 8). Using the HCT-CI categories of low (0), intermediate (1 or 2), and high risk (>3), there was no significant difference in TRM between the 3 groups. However, when the patients were divided into 2 groups, HCT-CI ≤ 3 or > 3, the incidence of TRM at 3 years after transplantation was 26% (95% confidence interval [CI], 17 to 36) in the HCT-CI ≤ 3 group versus 50% (95% CI, 30 to 67) in the HCT-CI > 3 group (P = .01). Overall survival for patients with HCT-CI ≤ 3 was 40% (95% CI, 27 to 51) versus 29% in patients with HCT-CI >3 (95% CI, 12 to 48) (P = .08). Our study demonstrates that HCT-CI score > 3 is associated with an increased risk of TRM at 3 years after transplantation in patients undergoing RIC CBT. Because of the significant risk of TRM in patients with HCT-CI > 3 compared with risk for those with HCT-CI ≤ 3, patients with an HCT-CI score >3 should be counseled before undergoing RIC CBT.