Does the Hematopoietic Cell Transplantation Specific Comorbidity Index Predict Transplant Outcomes? A Validation Study in a Large Cohort of Umbilical Cord Blood and Matched Related Donor Transplants

Abstract

The hematopoietic cell transplantation specific comorbidity index (HCT-CI) has been recently proposed to predict the probability of nonrelapse mortality (NRM) and overall survival (OS) in allogeneic HCT recipients while taking into account any pretransplant comorbidity. We tested the validity of the HCT-CI in a cohort of 373 adult HCT recipients (184 matched-related donor and 189 unrelated umbilical cord blood) who received a myeloablative (N = 150) or nonmyeloablative (N = 223) conditioning regimen. HCT-CI scores of 0, 1, 2, and > or =3 were present in 58 (16%), 56 (15%), 64 (17%), and 195 (52%) patients, respectively. Pulmonary conditions were the most common comorbidity. Cumulative incidence of NRM at 2 years was 10%, 20%, 24%, and 28% for HCT-CI scores of 0, 1, 2, and > or =3, respectively (P = .01). The corresponding probability of OS at 2 years was 72%, 67%, 51%, and 48%, respectively (P < .01). On multivariate analyses adjusted for recipient age, disease risk, donor source, and conditioning regimen intensity, the relative risks for NRM for HCT-CI scores of 1, 2, and > or =3 (compared to a score of 0) were 2.0 (95% confidence intervals, 0.8-5.3), 2.6 (1.0-6.7), and 3.2 (1.4-7.4), respectively. The risks for overall mortality were 1.2 (0.6-2.1), 2.0 (1.1-3.4), and 2.1 (1.3-3.3), respectively. In subgroup analyses, the HCT-CI score did not consistently predict NRM and OS among different donor sources and conditioning regimens. The HCT-CI, although a useful tool for capturing pretransplant comorbidity and risk-assessment, needs to be further validated prior to adopting it for routine clinical use.

Role of HCT-comorbidity index, age and disease status at transplantation in predicting survival and non-relapse mortality in patients with myelodysplasia and leukemia undergoing reduced-intensity-conditioning hemopoeitic progenitor cell transplantation

“…[15][16][17][18] These comorbidity scores, such as haemopoietic progenitor cell transplantation (HCT)-comorbidity index (CI), have been validated in some studies to be useful in predicting NRM in transplant candidates in the setting of myeloablative compared with non-myeloablative transplants, albeit in a heterogenous group of patients receiving myeloablative and non-myeloablative TBI-based conditioning regimens. 15,18,19 In others, it was not found to be predictive of mortality on its own in HCT. 20,21 Patients having RIC allografts are, however, very heterogeneous as far as degree of comorbidity is concerned, and it is unclear whether these comorbidity scores can further delineate groups of RIC allograft recipients who will have significantly different NRM and survival.…”

Comorbidity index does not predict outcome in allogeneic myeloablative transplants conditioned with fludarabine/i.v. busulfan (FluBu4)

“…10 In umbilical cord transplant registry data, HCT-CI did not consistently predict TRM or OS. 11 Similarly, in patients with nonHodgkin's lymphoma conditioned with fludarabine and CY, there was no association between HCT-CI and TRM or OS. 12 Several investigators have reported that although HCT-CI may be useful, it lacks the sensitivity to predict outcome as stratified by the three original groups described.…”

Predictive value of risk assessment scores in patients with hematologic malignancies undergoing reduced‐intensity conditioning allogeneic stem cell transplantation

“…On the other hand, PAM score is a global risk assessment score including variable factors of comorbidity, condition of transplantation, and disease risk. The usefulness of these risk assessment scores has been validated by some previous studies [3][4][5][6][7][8][9][10][11][12][13], but the scores failed to predict mortality in other reports [14][15][16].…”