Usefulness of the hematopoietic cell transplantation-specific comorbidity index (HCT-CI) in predicting outcomes for adolescents and young adults with hematologic malignancies undergoing allogeneic stem cell transplant.

Background: The HCT-CI helps to predict non-relapse mortality (NRM) and overall survival (OS) in allogeneic hematopoietic cell transplantation (HCT) recipients. The usefulness of this index in a younger, adolescent and young adult (AYA) population is unclear.

Procedure: We tested the validity of the HCT-CI as a predictor of mortality in a retrospective cohort of 56 AYA recipients between the ages of 16 and 39, using chart abstraction followed by univariable and multivariate analysis.

Results: Only pulmonary dysfunction (46%), hepatic dysfunction (27%), infection (20%), and psychiatric disturbance (11%) had frequencies greater than 5% in this population. HCT-CI scores of 0-2 were present in 54%, and scores of >3 in 46%. The cumulative incidence of NRM at 2 years was 32%, with an OS of 46%; the NRM and OS for patients with an HCT-CI of 0-2 were 24% and 62%, whereas the NRM and OS for patients with an HCT-CI >3 were 38% and 28%. Patients with pulmonary dysfunction prior to transplant had a 29% OS at 2 years, compared to a 61% OS among patients without (P = 0.001). There was no statistically significant difference for patients and a worse NRM (P = 0.08). In multivariable analysis, both an HCT-CI score of >3 and any pulmonary dysfunction remained associated with OS (P = 0.01, P = 0.03), but neither with NRM.

Conclusions: The HCT-CI appears useful in predicting OS in AYAs, though higher scores may reflect prior treatment, with pulmonary dysfunction particularly prevalent. Prospective studies to further validate and explain these findings are warranted.