Ethnicity and hematopoietic stem cell transplantation outcomes in British Columbia, Canada

Background: There are documented ethnic disparities in cancer care access, use and clinical outcomes in North America. Hematopoietic stem cell transplantation (HSCT) is an established treatment for many hematological and non-hematological malignancies. The effect of ethnicity on unrelated-donor HSCT outcomes has not been studied in Canadian patients. Objective: To determine whether ethnicity is associated with unrelated donor HSCT outcomes in patients with hematologic malignancies in British Columbia, Canada. Design: Retrospective medical chart review Materials and Methods We reviewed the registry data of 395 patients receiving first time unrelated donor HSCT for hematological malignancies at the leukemia/BMT center of British Columbia (BC) between 1988 and 2008. A patient’s ethnicity was reported to be white (N=340), Asian (N=32), native (N=8), Hispanic (N=3), black (N=2), mixed (N=9) or other- not specified (N=1). For my analysis, ethnicity was further categorized as white (N=340) and non-white (N=55). HSCT outcomes were compared using log-rank test and Cox proportional hazard regression analysis adjusting for statistically-significant patient, disease and transplant-related factors. Results: No statistically significant difference for overall survival, non-relapse survival, grade II-IV acute graft versus host disease (aGVHD) and chronic graft versus host disease (cGVHD) rates were found between whites and non-whites. Analyzing a subset of 115 cases (88 whites and 27 non-whites) who received their transplant after June 2001 (the start of high resolution DNA-based human leukocyte antigen (HLA) matching in the study center) and had an underlying diagnosis of acute myeloid leukemia, acute lymphoid leukemia, chronic myeloid leukemia or myelodysplastic syndrome didn’t show any statistically significant difference for HSCT outcomes between whites and nonwhites either. Conclusion: According to our data, unrelated-donor HSCT clinical outcomes are comparable between patients having white and non-white ethnicity in BC. This finding contrasts with those of US studies. This might be due to: 1) different ethnic compositions of the BC and US populations 2) different access to health care for ethnic minorities in the BC and US populations 3) my analysis using a heterogeneous non-white ethnic group, and thereby potentially masking ethnic differences.Medicine, Faculty ofGraduat