Racial and Socioeconomic Disparities in Long-Term Outcomes in ≥1 Year Allogeneic Hematopoietic Cell Transplantation Survivors: A CIBMTR Analysis

Abstract

Racial/ethnic minorities have demonstrated a worse survival after allogeneic hematopoietic cell transplantation (HCT) compared to Whites. Whether the racial disparity in HCT outcomes persists in long-term survivors, and possibly may even be exacerbated in this population that frequently transitions back from the transplant center to their local healthcare providers, is unknown. In the current study we compared long-term outcomes among one-year allogeneic HCT survivors by race/ethnicity and socioeconomic status (SES). The Center for International Blood and Marrow Transplant (CIBMTR) database was used to identify 5,473 patients with acute myeloid leukemia, acute lymphocytic leukemia, chronic myeloid leukemia, or myelodysplastic syndromes who received first allogeneic HCT between 2007-2017 and were alive and in remission for at least 1 year after transplantation. Study was restricted to patients transplanted in the United States. SES was defined using patient neighborhood poverty level estimated from the recipient's ZIP code of residence; a ZIP code with ≥20% of persons below the federal poverty level was considered a high poverty area. The primary outcome was to evaluate the association of race/ethnicity and neighborhood poverty level with overall survival (OS), relapse, and non-relapse mortality (NRM). Cox regression models were used to determine associations of ethnicity/race and SES with (OS), relapse, and (NRM). Standardized mortality ratios (SMR) were calculated to compare mortality rates of the study patients to their general population peers matched on race/ethnicity, age and sex. Patients were reported to be Non-Hispanic White (n=4,385), Non-Hispanic Black (n=338), Hispanic (n=516), and Asian (n=234). Overall, 729 (13%) patients resided in areas with high poverty level. We found that a significantly larger proportion of non-Hispanic Black (37%) and Hispanic (26%) patients lived in areas with higher poverty levels compared to Non-Hispanic Whites (10%) and Asians (10%) (p<0.01). In multivariable analysis, we observed no significant association between OS, PFS, relapse, or NRM and race/ethnicity or poverty level when adjusted for patient-, disease- and transplant-related covariates. Our retrospective cohort registry study highlights that among adult allogeneic HCT recipients who survived at least 1-year in remission, there was no observed association between race/ethnicity, neighborhood poverty level, and long-term outcomes.