A study by Ivy Abraham, MD, of the University of Illinois at Chicago, and colleagues, investigated the contribution of structural violence, specifically neighborhood socioeconomic status, on the racial/ethnic differences in the survival of patients with acute myeloid leukemia (AML). They found that neighborhood socioeconomic status accounted for 37% and 50% of the racial disparity in death from leukemia and all causes, respectively.¹ The study was presented virtually at the 2020 American Society of Hematology (ASH) Annual Meeting & Exposition.

Ivy Abraham, MD

Irum Khan, MD

“This is the first study to integrate individual clinical and disease specific data with census tract data on the affluence, disadvantage, and segregation levels of the neighborhoods where patients live and analyze how these domains interact to influence outcomes for patients with AML,” said senior study author Irum Khan, MD, of the University of Illinois at Chicago.

Previous studies have shown that non-Hispanic Black and Hispanic patients with AML have higher mortality rates than non-Hispanic White patients diagnosed with the disease despite lower rates of incidence, more favorable genetics, and a younger age at disease onset.²

Study Methodology

The researchers analyzed census tract data on 822 non-Hispanic White (n = 497), non-Hispanic Black (n = 126), Hispanic (n = 117), and other (n = 82) adult patients diagnosed with AML between 2012 and 2018 at six academic cancer centers in Chicago. The data were collected using the Federal Financial Institutions Examination Council (FFIEC) Geocoding/Mapping System, and computed tract disadvantage and tract affluence scores were then categorized into distribution tertiles (low, moderate, and high).

Time to relapse and death from leukemia were examined, with adjustments made for age, gender, and race/ethnicity (baseline models) and for potential mediators of racial disparities, including distal (Charlson Comorbidity Index [CCI], obesity, concentrated disadvantage, and affluence, health insurance status), and proximal mediators (somatic mutations and European LeukemiaNet [ELN] prognostic score categories).

Key Results

The researchers found significant heterogeneity in patients’ age and comorbidities at diagnosis, with Hispanic patients being the youngest and having the lowest CCI score. Morbid obesity was more prevalent in non-Hispanic Black and Hispanic patients, 23% and 20%, respectively, compared with non-Hispanic White patients, 11%. Payer source also differed significantly, with private insurance twice as frequent among non-Hispanic White patients than non-Hispanic Black patients, 51% vs 25%. The largest uninsured population was Hispanic.

According to the ELN prognostic score, adverse risk disease was most prevalent in non-Hispanic White patients; NPM1 gene mutations were least prevalent in Hispanic patients, and TP53 mutations were more prevalent in non-Hispanic Black patients, 26%, compared with non-Hispanic White patients, 12%, and Hispanic patients, 9%. Due to the low numbers, these differences were not statistically significant (P = .10).

The researchers also found that non-Hispanic Black patients and Hispanic patients resided in more disadvantaged and less affluent areas than non-Hispanic White patients. Treatment data were available for 764 patients; 75% of patients received intensive induction therapy, and the choice of first-line treatment did not differ by race or tract disadvantage. However, allogeneic transplant rates did differ by race, age, insurance status, tract disadvantage, and ELN prognostic score.

Complications from induction chemotherapy, as reflected by intensive care unit (ICU) admissions during induction, were significantly lower in non-Hispanic White patients, 25%, compared with non-Hispanic Black patients, 39%, and Hispanic patients, 42%. ICU admission rates were significantly higher among patients with morbid obesity and low-tract affluence.

Mortality Findings

The researchers’ analyses also found that compared with non-Hispanic White ethnicity, minority ethnicity was associated with a 42% increased hazard of death from leukemia (hazard ratio [HR] = 1.42, 95% confidence interval [CI] = 1.09–1.85) and a 36% increased hazard of death from all causes (HR = 1.36, 95% CI = 1.07–1.72), each after controlling for age, gender, and study site. Adjustment for continuous tract disadvantage and affluence and their interaction lowered both the hazard of leukemia and all-cause death to 1.18 (95% CI = 0.88–1.60) and 1.14 (95% CI = 0.88–1.49), respectively. In formal mediation analysis, neighborhood socioeconomic status accounted for 37% (P = .09) and 50% (P = .02) of the racial disparity in death from leukemia and all causes, respectively.

Causes of Outcome Disparities

“Notably, our mediation analysis shows that census tract level socioeconomic status explains a substantial proportion of the disparity in hazard of leukemia death. In addition, the observed disparities in treatment complications of induction chemotherapy, as reflected by ICU admissions, and the continued disparity in allogeneic transplant utilization all warrant further study. These results draw attention to the need for deeper investigation into the social and economic barriers to successful treatment outcomes for patients with leukemia and represent an important first step toward designing strategies to mitigate these persistent health inequities,” concluded the study authors.

“These findings point to a need for more research on the social and economic barriers to successful treatment outcomes for patients with AML. Similar to molecular tailoring of therapy, evaluation of social determinants of health should be a key aspect of personalized leukemia therapy,” said Dr. Khan. “While the field is in its infancy, our analysis suggests that incorporating validated measures of social determinants of health into clinical care is ­likely to contribute significantly to narrowing disparities in leukemia survival.” 

DISCLOSURE: Dr. Abraham reported no conflicts of interest. Dr. Khan has served as a consultant for Celgene and Amgen; has received honoraria from Incyte; and has received research funding from Takeda.

REFERENCES

1. Abraham I, Rauscher G, Patel AA, et al: The role of structural violence in acute myeloid leukemia outcomes. 2020 ASH Annual Meeting & Exposition. Abstract 217. Presented December 5, 2020.

2. Darbinyan K, Shastri A, Budhathoki A, et al: Hispanic ethnicity is associated with younger age at presentation but worse survival in acute myeloid leukemia. Blood Adv 1:2120-2123, 2017.