The Role of Race on Survival after Alternative Donor Hematopoietic Progenitor Cell Transplant for Pediatric Acute Leukemia: Provocative Single Center Data.

Allogeneic blood or bone marrow transplant (BMT) can be a curative treatment for many children and adolescents with acute leukemia. With advances in unrelated donor transplant, others and we have shown that unrelated donor BMT can have similar survival to matched sibling BMT. There are several reports describing outcomes after matched related donor transplantation among various ethnic groups. Thus far, there are no published studies comparing outcomes among ethnic groups after alternative donor transplantation. Anecdotally, however, there have been concerns regarding outcomes among racial and ethnic groups, especially African-Americans. In order to address this question, we utilized our institutional database to analyze survival among children and adolescents receiving an alternative donor BMT at Children’s Hospital of Wisconsin from 1988-present. We compared survival in Caucasians and African-Americans undergoing unrelated donor and mismatched related donor transplantation (including haploidentical donors). One hundred and twenty four Caucasians underwent matched and mismatched unrelated donor transplantation compared to 11 African Americans. The 2-year probabilities of overall survival were significantly better for Caucasians at 53% (95% CI 44–62) than for African Americans, 18% (95% CI 2–45), p=0.01. Fifty-four Caucasians and 9 African Americans received mismatched family donor transplantation. Corresponding probabilities of overall 2-year survival were 38% (95% CI 25–51) and 30% (95% CI 5–64), respectively. Interestingly, our data show no statistically significant difference in survival after mismatched related donor transplantation between the Caucasian and African-American cohorts. Our data should be interpreted cautiously as the number of African Americans transplanted at our institution is few. Additionally, our analysis is limited by our inability to adjust for disease status at transplantation, HLA disparity and other known risk factors that may impact survival. Nevertheless these observations from a single institution cannot be ignored and warrant further analysis in a larger cohort such that outcomes after transplantation may be adjusted appropriately for relevant risk factors. We believe that a national database/registry study will have the numbers necessary to answer the questions that need to be asked regarding outcomes with alternative donor transplantation in the African-American population. We also believe that as cell processing and supportive care technologies improve mismatched family member transplantation outcomes, these advances could have a significant impact in improving leukemia-free survival for African-American children and adolescents.