Exploring Outcomes by Ethnicity in Allogeneic Hematopoietic Cell Transplantation

Clinical outcome disparities among racial and ethnic groups have been described following allogeneic hematopoietic cell transplantation (HCT). This study investigated the impact of race and ethnicity on HCT outcomes in a multi-ethnic single-center population.

We analyzed outcomes of 709 allogeneic HCT patients, stratified by racial and ethnic groups, who underwent allogeneic HCT between January 2018 and April 2022. Outcomes examined included overall survival (OS), cumulative incidence of relapse (CIR), non-relapse mortality (NRM), and graft-versus-host disease/relapse-free survival (GRFS).

No significant differences in OS, CIR, NRM, GRFS, acute GVHD (aGVHD), or chronic GVHD (cGVHD) were observed. Significant differences in age, use of human leukocyte antigen-mismatched donors (HLA-MM), and HCT-CI comorbidity scores ≥ 3 across racial and ethnic groups were observed. Overall mean age was 58 years, with Black patients having the youngest mean age of 43 (range 22-73) and White patients the highest mean age of 59 (range 18-76) (p < 0.001). HCT-CI score ≥ 3 was seen in 35.9% of the entire cohort, varying by race and ethnicity: 60.5% in Black, 41.4% in South Asian, 31.5% in White, and 29.0% in East Asian patients (p < 0.001). Utilization of HLA-MM donors (including haploidentical) was 29.2% overall, with highest frequencies in Black (65.1%) and East Asian (45%) patients, and lowest in White patients (20.4%) (p < 0.001).

Statistically significant differences were observed across self-identified racial and ethnic groups regarding age, HCT-CI ≥ 3, and the use of HLA-MM donors. However, post-allogeneic HCT outcomes did not differ significantly by race or ethnicity. Larger prospective trials are warranted to validate our findings.