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.

Reduced-intensity-conditioning (RIC) regimens have allowed older patients to have allogeneic hemopoietic progenitor cell transplantation (HCT). This retrospective study was done to assess the impact of the HCT-comorbidity index (HCT-CI) in addition to other pre-transplant factors on the outcome of RIC transplants. In all 121 such patients were transplanted between 2002 and 2008 at two centers using fludarabine, melphalan and alumtuzumab conditioning. The OS and non-relapse mortality (NRM) were 56% and 30% at 2 years, respectively. The NRM of patients with HCT-CI ≥ 3 was not significantly different from the NRM of those with HCT-CI 0-2 (P value 0.24). Age and disease status at transplantation were significant factors affecting OS (P value 0.07 and 0.008, respectively), with no impact on NRM (P value 0.14 and 0.24, respectively). Although HCT-CI on its own did not independently predict NRM or survival, taken together with age and disease status at transplantation, it can be utilized to further delineate RIC allograft recipients into groups with different outcomes. Patients with none or one of these three adverse factors (age ≥ 60 years, leukemia in second CR or PR/high-risk myelodysplasia (MDS) and HCT-CI ≥ 3) had a 2-year NRM and survival of 18% and 80%, respectively, which was significantly better than those of patients with two or more of these adverse factors with 2-year NRM and survival of 46% (P value 0.03) and 40% (P value 0.02), respectively. None of the patients with all three adverse factors (age ≥ 60 years, leukemia in second CR or PR/high-risk MDS and HCT-CI ≥ 3) had survived for 2 years (median survival 12 months). This information can be used to guide patient selection for RIC transplants and to appropriately counsel patients of the risks and benefits of this treatment.