Trends in Survival Rates After Allogeneic Hematopoietic Stem-Cell Transplantation for Acute and Chronic Leukemia by Ethnicity in the United States and Canada

Abstract

Purpose: Differences in survival among ethnic groups in the United States are reported in numerous diseases and treatment strategies. Whether survival after allogeneic hematopoietic stem-cell transplantation (HSCT) differs by ethnicity is uncertain. Patients and Methods: Patients (n = 6,443) receiving HLA-identical sibling HSCT for acute or chronic leukemia in the United States or Canada between 1985 and 1999 and reported to the International Bone Marrow Transplant Registry were included. The survival of recipients reported as white, black, Hispanic, or Asian was compared using Cox proportional hazards regression adjusting for other clinical factors. Three 5-year periods were studied to evaluate changes over time. Results: Hispanics compared with whites had lower 1-year (53% v 65%; P < .001) and 3-year adjusted survival rates (38% v 53%; P < .001) between 1995 and 1999, the most recent period studied. We failed to find significant differences in survival rates comparing whites with blacks or with Asians in any of the time periods. Overall survival for the entire cohort improved over time, from 56% to 63% at 1 year and from 43% to 51% at 3 years, with greater improvements noted among blacks (45% to 61% at 1 year and 34% to 48% at 3 years). Conclusion: Disparities remain in survival rates between whites and Hispanics despite adjustment for clinical factors. Factors not accounted for in this analysis, such as comorbid disease, socioeconomic status, healthcare access and delivery, and psychosocial and cultural variables, require further prospective study.