The Hematopoietic Cell Transplantation-Specific Comorbidity Index Fails to Predict Outcomes in High-Risk AML Patients Undergoing Allogeneic Transplantation—Investigation of Potential Limitations of the Index

In the context of allogeneic hematopoietic cell transplantation (allo-HSCT), comorbidities are an important risk factor. Use of the hematopoietic cell transplantation-specific comorbidity index (HSCT-CI), which was developed and validated in Seattle, Washington, has been proposed to predict the probability of nonrelapse mortality (NRM) and overall survival (OS) following allo-HSCT. We performed a single-center retrospective study to validate the prognostic impact of HSCT-CI on transplant outcomes in a cohort of high-risk acute myeloid leukemia patients undergoing allo-HSCT between January 2000 and December 2008. The median patient age at the time of transplantation was 53 years (range: 11-76 years). The median pretransplantation HSCT-CI score was 4 (range: 0-10). Among 340 patients, OS at 3 years was 29% (95% confidence interval [CI]: 17%-41%), 40% (33%-47%), and 44% (41%-47%) in the low-, intermediate-, and high-risk HSCT-CI groups (P = .7), respectively. The corresponding NRM at 3 years was 34% (10%-58%), 32% (20%-44%), and 26% (20%-32%; P = .6). In multivariate analysis, we found no predictive value of HSCT-CI for either OS or NRM. The use of HSCT-CI as a decision-making tool for transplantation eligibility should not be considered until its validity has been unequivocally shown in crossvalidation studies.