Ethnic Disparities in Allogeneic Hematopoietic Cell Transplantation: A Secondary CIBMTR Study

Background: Allogeneic Hematopoietic Cell Transplantation (allo-HCT) is a necessary therapeutic option for patients with Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL). This study aims to evaluate the effects of race on the outcomes of allo-HCT. Methods: This secondary data analysis utilized the Center for International Blood and Marrow Transplant Research (CIBMTR) data repository for allo-HCT cases in the United States from 2008 to 2018. The eligible patients were aged 18 or older, undergoing initial allo-HCT for AML or ALL from an HLA-identical sibling or 8/8 matched unrelated donor. Recipient, disease, and transplant variables were assessed. A Cox proportional hazards model was employed for multivariable analysis. Results: The dataset included 4,783 cases, with 4,310 White, 211 Black, 230 Asian, 12 Native Hawaiian/Pacific Islander, and 26 American Indian/Alaska Native individuals. Asians had a significantly higher mortality rate when receiving transplants from HLA-identical siblings compared to well-matched unrelated donors (76.56 vs. 41.91%, p=0.001). The median survival times did not differ significantly among the racial and ethnic groups. White (39.08 months), Black or African American (25.16 months), Asian (62.27 months), Native Hawaiian or other Pacific Islanders (25.33 months), and the overall estimated median survival across all groups was 39.14 months (log rank test p=0.870). After adjusting for age, disease type, and donor type, Black or African American individuals had a 25.2% higher risk of death compared to White individuals (HR: 1.252 95%CI: (1.043, 1.503) p=0.016). Conclusion: This study reveals significant disparities in outcomes among different racial and ethnic groups