Children with AML from poor neighborhoods face twofold greater risk for death
ORLANDO — ZIP code-based low socioeconomic status appeared associated with an increased risk for mortality among children with acute myeloid leukemia treated on clinical trials, according to study results presented at ASH Annual Meeting and Exposition.
In fact, children from neighborhoods with a low area-based income had a 2.4 times greater risk for early death than children living in areas with middle or high income.
“Although I frankly did not find the significant survival disparities among patients from low-income neighborhoods surprising based on my clinical experience and firsthand caring for patients, the degree to which ZIP code impacts survival and, in particular, early mortality, is nevertheless remarkable,” Lena E. Winestone, MD, MSHP, assistant professor in the department of pediatrics at University of California, San Francisco and pediatric hematologist and oncologist at UCSF Benioff Children’s Hospital told Healio. “Understanding the impact of neighborhood on survival is the first step, but additional studies to investigate the relationship to known racial and ethnic disparities will allow us to begin to mitigate disparities and ensure equitable outcomes across our patient population.”
Because income, education and health insurance coverage are known factors that affect receipt of oncology care, Winestone and colleagues sought to evaluate how area-based measures of socioeconomic status contributed to outcomes disparities among children with AML treated on two Children’s Oncology Group phase 3 clinical trials. Although participation on a clinical trial is thought to level access to care, researchers hypothesized that patients from low income and education ZIP codes would have inferior 5-year OS and EFS.
“The role of socioeconomic factors in outcomes for pediatric acute lymphoblastic leukemia is well-documented and has largely been linked to oral chemotherapy adherence,” Winestone told Healio. “However, socioeconomic factors have not been evaluated in pediatric AML at the national level or within the Children’s Oncology Group to date. Because the backbone chemotherapy is administered in the inpatient setting, adherence to chemotherapy can largely be removed as a possible contributor to outcome disparities in pediatric AML.”
Of the 2,387 patients enrolled on the AAML0531 and AAML1031 clinical trials, 1,467 met the exclusion criteria for the current analysis and had adequate covariate data.
Researchers assessed ZIP code level median annual household income to define patients’ neighborhoods as being in poverty (< $24,250; n = 27), low ($24,250-$56,516; n = 954) and middle/high (> $56,516; n = 695) income areas. They also assessed ZIP code level educational attainment and insurance coverage.
Overall, black and Hispanic children were more likely than white children to live in poverty, low-income and low-education areas, and they were more likely to have Medicaid-only insurance.
Researchers found that rates of 5-year OS were significantly lower among children living in poverty (43%) and low-income areas (61%) compared with those living in middle/high-income areas (68%; P = .004). They observed a similar trend for 5-year EFS (34% vs. 46% vs. 54%; P = .005).
Patients living in areas of lowest educational attainment also demonstrated poorer rates of 5-year OS (58% vs. 70%; P = .005) and EFS (44% vs. 54%; P = .03) than those living in the areas with the highest educational attainment.
Having Medicaid-only insurance was associated with lower rates of 5-year OS (59 ± 5% vs. 66 ± 3%; P = .01) but similar rates of EFS (48 ± 5% vs. 50 ± 3%).
Even after adjusting for area-based education, insurance and established risk factors, results of a multivariable model showed children from middle/high-income areas had a 21% reduced risk for mortality compared with children from low-income areas (adjusted HR = 0.79; 95% CI, 0.63-0.99). They also demonstrated an improvement in EFS (adjusted HR = 0.77; 95% CI, 0.65-0.89).
However, the differences in survival according to area-based educational attainment and insurance coverage did not persist on the multivariable analysis, suggesting that area-based income and established risk factors may be driving the association, according to the researchers.
Moreover, area-based low income was associated with an increased risk for early death (OR = 2.43; 95% CI, 1.04-5.69) and higher incidence of treatment-related mortality (11.1 ± 10.5% vs. 3.7 ± 2.5%; P = .03) compared with high/middle-income areas.
“Just as race/ethnicity, gender and age are often included in analyses of results, these data suggest that area-based income should also be incorporated into risk models of pediatric AML,” Winestone told Healio. “Moreover, now that we have appended these variables to the Children’s Oncology Group master dataset, they are available for other investigators to incorporate into their analyses. It is my hope that our findings will also lead to the prospective collection of individual socioeconomic factors — such as income, education and employment — through upcoming clinical trials. Collection of these data would allow us to start identifying specific individual patients who would benefit from targeted poverty-directed interventions.”
Such interventions might include providing resources like transportation, nutrition or housing, or offering tailored support from a health navigator who can help with insurance issues, follow-up, low health literacy and lack of trust, Winestone added. Clinicians may also consider changes in medical management of comorbidities and complications that tend to impact patients from low socioeconomic areas.
Moving forward, researchers aim to further understand why these disparities persisted even among patients treated on clinical trials.
“One possible explanation we are currently investigating is potential differences in supportive care because most of the gains in survival in pediatric AML have been related to supportive care rather than benefits from chemotherapy or other AML-targeted therapies,” Winestone said. “Although these clinical trials included in this study contained recommendations for supportive care management, such as antibiotic prophylaxis and screening for cardiotoxicity, these were not mandated by the trial and thus could be a place where care differed.
“In addition, the disparity in early deaths we observed suggests that patients from low-income areas may die before they have the opportunity to benefit from the care received through the clinical trial,” she added. – by Alexandra Todak
Winestone LE, et al. Abstract 703. Presented at: ASH Annual Meeting and Exposition; Dec. 7-10, 2019; Orlando.
Disclosures: Winestone reports no relevant financial disclosures. One study author reports research funding from Merck and Pfizer and a data safety monitoring board chair role for an antifungal study by Astellas.