Structural violence may be linked to increased risk for death among adults with AML
Structural violence appeared associated with an increased risk for death among certain minority adults with acute myeloid leukemia, according to study results presented at the virtual ASH Annual Meeting and Exposition.
“The concept of structural violence was introduced in the 1960s and was defined as the cause of the difference between the potential and the actual conditions realized by humans. In the late 1990s, the term was co-opted into health sciences,” Irum Khan, MD, researcher in the division of hematology and oncology at University of Illinois, said during a presentation. “Structural violence looks at social processes through which health inequalities are produced and perpetuated. Reduced access to resources and mechanisms of social exclusion result in marginalization at both the individual and community levels. These multilevel factors often interact, creating a highly concentrated disadvantage often in urban poverty areas.”
Although Black and Hispanic adult and young adult patients with AML have a higher prevalence of favorable cytogenetics and a younger age at diagnosis than their white counterparts, they also have lower survival rates, Khan added.
“Factors contributing to this include the fact that Black patients are less likely to receive intensive chemotherapy and allogeneic transplant for AML and that Blacks and Hispanics are more likely to be treated at hospitals with low volumes of AML,” Khan said. “However, we identified a gap in the literature whereby most of the disparities data in AML were based upon single-institution experiences with discrepant results or secondary analysis of large databases lacking detailed cytogenetic and molecular data with details of treatment administered and early complications.”
Khan and colleagues performed a multilevel analysis of disparities in AML to investigate the role of structural violence — with a specific focus on neighborhood socioeconomic status — on racial and ethnic differences in leukemia-specific survival. The analysis included 822 adults diagnosed with AML between 2012 and 2018 across six academic cancer centers in metropolitan Chicago. Most patients were white (n = 497), followed by Black (n = 126), Hispanic (n = 117) and members of other racial and ethnic groups (n = 82).
Researchers collected census tract data and categorized tract disadvantage and tract affluence scores into low, moderate or high distribution tertiles. They also assessed time to relapse and death due to leukemia after adjusting for age, gender, race/ethnicity, and potential mediators of racial disparities, including Charlson Comorbidity Index, obesity, health insurance status and somatic mutations.
Researchers observed significant heterogeneity across the study cohort in terms of age and comorbidities at diagnosis. Hispanic patients tended to be younger at diagnosis — with 41% diagnosed between the ages of 40 and 59 years — than Black patients and white patients (30% for both). Fewer than half of Hispanic patients (48%) had a Charlson Comorbidity Index a score of 2 or higher, compared with 65% of Black patients and 69% of white patients.
Significant differences also were observed in payer source, with private insurance more than twice as common among white patients vs. Black patients (51% vs. 25%). Hispanic patients encompassed the largest uninsured population (22%) compared with both Black patients and white patients (3% for both).
Two-thirds (68%) of Black patients and white patients and 80% of Hispanic patients underwent intensive induction therapy, with no significant differences in first-line therapy choice according to race or tract disadvantage. However, researchers observed substantially higher rates of allogeneic stem cell transplantation among white patients (47%) and Hispanic patients (42%) compared with Black patients (22%).
ICU admission rates after induction chemotherapy were significantly higher among Hispanic patients (41%) and Black patients (38%) than white patients (26%).
“The rates were significantly higher among patients who were morbidly obese and of low tract affluence,” Khan said. “This is an area that is relatively unexplored and merits attention, as it is amendable to intervention.”
After controlling for age, gender and study site, minority race/ethnicity appeared associated with a 42% increased hazard of death due to leukemia (HR = 1.42; 95% CI, 1.09-1.85) and a 36% increased hazard of death due to all causes (HR = 1.36; 95% CI, 1.07-1.72). When the researchers adjusted for continuous tract disadvantage and affluence, the HRs decreased to 1.18 (95% CI, 0.88-1.6) for death due to leukemia and 1.14 (95% CI, 0.88-1.49) for all-cause death.
Results of formal mediation analysis showed neighborhood socioeconomic status accounted for 37% of the racial disparity in death due to leukemia, which did not reach statistical significance, and 50% (P = .02) due to all causes.
Specifically, tract socioeconomic status accounted for 81% of the disparity in leukemia survival between Black patients and white patients, according to Khan.
“Interestingly, comorbidities and molecular disease-specific differences did not mediate Black vs. white or white vs. nonwhite disparities in leukemia-specific death,” Khan said. “This study is the first to integrate clinical and molecular data, neighborhood characteristics and treatment patterns to disentangle racial and ethnic disparities in adult AML survival. Census tract socioeconomic status explains a substantial proportion of the disparity in the survival of [patients with leukemia], and our study highlights the need for validated measures of structural violence.”
Future directions of this research include mixed methods studies along with engagement with community partners to identify social and economic barriers, as well as additional studies to gain insights into biologic pathways relevant to structural violence and the development of a prognostic calculator that encompasses measures of structural violence, Khan added.
“Incorporation of measures of social determinants of health is likely to contribute significantly to narrowing disparities in leukemia survival as shown by our mediation analyses,” she said. “Analogous to molecular tailoring of therapy, social determinants of health measures need to be recognized as a key aspect of personalized leukemia therapy.”
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Abraham I, et al. Abstract 217. Presented at: ASH Annual Meeting and Exposition (virtual meeting); Dec. 5-8, 2020.
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