How do differences in treatment impact racial and ethnic disparities in acute myeloid leukemia?

BACKGROUND: We previously demonstrated disparate acute myelogenous leukemia (AML) survival for black and Hispanic patients; these differences persisted despite younger ages and higher prevalence of favorable cytogenetics in these groups. This study determined: (i) whether there are differences in treatment delivered to minorities, and (ii) how these differences affect outcomes in AML. We hypothesize that differences in treatment explain some proportion of survival disparities.
METHODS: We used California Cancer Registry data linked to hospital discharge abstracts for patients with AML (1998-2008). Logistic regression models estimated odds of treatment (chemotherapy and/or hematopoietic stem cell transplant) by race/ethnicity. Cox proportional hazard models estimated mortality by race after adjustment for treatment.
RESULTS: We analyzed 11,084 records. Black race was associated with lower odds of chemotherapy [OR, 0.74; 95% confidence interval (CI), 0.61-0.91]. Black and Hispanic patients had decreased odds of transplant [(OR, 0.64; 95% CI, 0.46-0.87); (OR, 0.74; 95% CI, 0.62-0.89), respectively]. Black patients had increased hazard of mortality (HR, 1.14; 95% CI, 1.04-1.25) compared with whites. Adjustment for receipt of any treatment resulted in decreased mortality (HR, 1.09; 95% CI, 1.00-1.20) for black patients.
CONCLUSIONS: AML treatment differences for black patients explain some proportion of the disparity. Future AML disparities studies should investigate socioeconomic and other characteristics. IMPACT: Study findings may better elucidate drivers of disparities in AML. ©2015 American Association for Cancer Research.