Assessment of the Hematopoietic Cell Transplantation Comorbidity Index in Patients Receiving Reduced-Intensity Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is an established therapy for malignant and nonmalignant hematologic disorders. Reduced-intensity conditioning (RIC) regimens have expanded the use of HSCT to the elderly patients and to patients that are otherwise ineligible for conventional transplants. However, RIC HSCT still remains associated with a significant morbidity and mortality and the careful assessment of risks and benefits before transplantation is essential. Major factors which influence non-relapse mortality (NRM) and overall survival (OS) after HSCT are diagnosis, type of transplant and the patient's risk profile, which includes age and presence of comorbidities. The use of the hematopoietic cell transplantation-specific comorbidity index (HSCT-CI) has been proposed to predict the probability of non-relapse mortality (NRM) and overall survival (OS) following HSCT. Since its development, HSCT-CI has been evaluated at different institutions for various hematologic diseases. We performed a single-center retrospective study to assess the prognostic value of HSCT-CI on transplant outcomes in a cohort of patients undergoing RIC HSCT. We analyze patients receiving a RIC HSCT between January 2005 and December 2010. The median patient age at the time of transplantation was 57 years (range: 19-75 years). The patient diagnoses included AML (32%), NHL (28%), MM (15%), MDS (10%), HD (5%), CLL (5%), ALL (3%), MPD (1%) and nonmalignant hematologic (1%). The median pre-transplantation HSCT-CI score was 2 (range: 0-9). Among 133 patients, OS at 2 years was 36%. The 2 yr OS is 34%, 33% and 41% in the low-, intermediate-, and high-risk HSCT-CI groups respectively (p = 0.72). The corresponding NRM at 2 years was 39%, 41% and 38% (p = 0.85). Further subgroup analysis (patient age, diagnosis, conditioning, remission status and prior stem cell transplant) disclosed no significant differences in the OS prediction by the HCT-CI score. In conclusion, we found no predictive value of HSCT-CI for the determination of 2-year OS or 2-year NRM in allogeneic HSCT receiving reduced-intensity condition.