High Disease Burden at Acute Leukemia Diagnosis More Common in Black Children, Study Finds

A study evaluating disparities in disease burden, organ dysfunction, vital signs, and timing of therapy among children with acute leukemia found that Black children are more likely to present with higher disease burden at diagnosis compared with non-Hispanic White children.¹

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The analysis used electronic health record data from Children's Hospital of Philadelphia and Texas Children's Hospital—both large, diverse academic cancer centers—to identify factors potentially contributing to survival disparities among children with acute leukemia. The findings were published in Pediatric Blood Cancer.

“Racial and ethnic disparities in mortality among children with acute leukemia are only partially understood,” study authors Winestone et al wrote, adding that the induction period of chemotherapy treatment is when mortality is the highest.¹ In a previous study conducted by Winestone and colleagues, patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) were more prone to induction complications, and those with AML who experienced multiorgan system failure and require intensive care were at a substantially higher risk of death during this period compared with other patients.²

While intensive care unit (ICU)–level resources are more commonly needed by Black patients compared with White patients at initial presentation, they noted that after accounting for ICU care received in the first 72 hours, there were no racial differences in terms of ICU resources required during the induction time frame.²

“This suggests that clinical status in the peri-diagnostic period drives disparities in early mortality and overall survival in AML,” the authors wrote.¹ “In contrast, despite persistence of racial and ethnic disparities in ALL survival, induction mortality disparities were not observed in recent cooperative group clinical trials.”

The present study aimed to determine potential contributors to disparities in survival across racial and ethnic groups by exploring racial, ethnic, and socioeconomic status (SES) differences in clinical severity at initial presentation and during leukemia management. The authors expected Black patients to more frequently present with abnormal vital signs and laboratory results within 72 hours of admission, but they did not expect to see differences in timing of diagnosis or treatment.

A total of 899 patients diagnosed with acute leukemia from 2006 to 2014 were included in the study, the majority of whom were male and aged 1 to 9 years. Patients were categorized as non-Hispanic White (n = 474), Hispanic (318), or Black (n = 107), and the authors noted the exclusion of patients with race specified as Asian, other, or unknown due to small sample sizes.

At presentation, all groups showed similar vital signs. However, Black patients with AML were more likely to present with an elevated white blood cell (WBC) count (prevalence ratio [PR], 2.46; 95% CI, 1.10-5.50) and elevated uric acid (PR, 2.37; 95% CI, 1.33-4.16). Coagulopathy was more prevalent among Black patients with ALL (PR, 2.07; 95% CI, 1.04-4.10).

Having 2 or more laboratory abnormalities at presentation was more prevalent in Black patients with AML (PR, 2.16; 95% CI; 0.64-7.34) or ALL (PR, 2.20; 95% CI, 1.15-4.23), and the data suggest an increased prevalence of hepatic dysfunction (PR, 2.26; 95% CI, 0.41-12.51) or renal dysfunction (PR, 2.60; 95% CI, 0.65-10.40) in Black patients with AML.

While Hispanic patients showed a higher prevalence of renal dysfunction (PR, 3.45; 95% CI, 0.82-14.42), this subgroup did not show statistically significantly different laboratory findings. Neighborhood SES did not show statistically significant association with AML or ALL outcomes in the study.

The median time to receipt of complete blood count (CBC) testing was less than 2 hours across racial and ethnic groups, and the median time to bone marrow biopsy and lumbar puncture was 25-38 hours. The time to induction chemotherapy was a median of 2 to 3 days across groups. There were longer median times to diagnostic evaluations for Black and Hispanic patients vs non-Hispanic White patients, with the differences in time to bone marrow evaluation and lumbar puncture showing statistical significance.

The study had limited power to detect statistically significant differences, especially in rare populations or for rare outcomes, the authors noted. There is also a risk of controlled confounding because some analyses were unadjusted. Individual-level SES and insurance data were also not available.

“The concentration of disparities in AML may be related to the prevalence of presentation acuity and early mortality relative to ALL,” the authors wrote. "These data generate additional questions and hypotheses; for example, could strengthening supportive care immediately following diagnosis prevent complications associated with high disease burden? Another approach could focus on improving upstream referral pathways and limiting insurance barriers to allow for earlier intervention prior to the development of organ dysfunction."

In future research, the authors noted the importance of confirming these findings in larger cohorts treated on and off clinical trials and including adults. Determining the social or biologic factors driving high disease burden is also key to identify potential interventions to reduce disease burden in Black patients with AML.

References

1. Winestone LE, Getz KD, Li Y, et al. Racial and ethnic disparities in acuity of presentation among children with newly diagnosed acute leukemia. Pediatr Blood Cancer. Published online October 19, 2023. doi:10.1002/pbc.30726

2. Winestone LE, Getz KD, Miller TP, et al. The role of acuity of illness at presentation in early mortality in black children with acute myeloid leukemia. Am J Hematol. 2017;92(2):141-148. doi:10.1002/ajh.24605