Introduction: Previous literature suggests that allogeneic hematopoietic stem cell transplant (HCT) utilization rates are lower amongst Hispanic and Black compared to non-Hispanic White (NHW) cancer patients. However, no previous studies have focused explicitly on the pediatric and adolescent young adult (AYA) population. We sought to examine utilization of HCT by race/ethnicity using the California Cancer Registry (CCR) and the Office of Statewide Health Planning and Development (OSHPD) hospitalization database. We hypothesized that Black and Hispanic patients with acute leukemia less frequently receive HCT than NHW patients. Methods: Using population-based data from California, a retrospective cohort of patients aged 0-39 years with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) diagnosed between 2000 and 2015 was assembled. The primary exposure was a composite of race/ethnicity with NHW patients as the reference group. The primary outcome was receipt of first HCT, defined by diagnosis codes in OSHPD or treatment in the CCR. Logistic regression analyses were used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI). Multivariable models were adjusted for race/ethnicity, age, sex, year of diagnosis, leukemia type, insurance type at diagnosis, rurality, and neighborhood socioeconomic status at diagnosis (SES). Results: Among 7,183 patients (4,790 with ALL and 2,393 with AML), 21% (16% of ALL patients and 31% of AML patients) underwent HCT. Distributions of insurance type and neighborhood SES differed by race/ethnicity with a higher proportion of Black and Hispanic patients having Medicaid insurance and living in lower SES neighborhoods. In univariate analyses, Black and Hispanic race/ethnicity were associated with decreased likelihood of receiving HCT (OR 0.70 95% CI 0.53, 0.94 and OR 0.77 95% CI 0.68, 0.88, respectively) and Asian race was associated with increased likelihood of HCT (OR 1.29 95% CI 1.07, 1.56) compared to NHW patients. In the multivariable model, there was no statistically significant difference in receipt of HCT among Hispanic patients, but disparities persisted among Black patients (Table 1). Uninsured patients and those in the lowest SES quintile were also less likely to receive HCT, while older age and AML were associated with HCT receipt. In analyses stratified by age and leukemia type, we found that the disparities in receipt of HCT among Black patients was largely driven by patients >20 years old (adjusted OR 0.50 95% CI 0.33, 0.78). These analyses also revealed that the increased likelihood of HCT among Asian/PI patients was driven by patients <21 years old with ALL (adjusted OR 1.59 95% CI 1.07, 2.38). Among those who did undergo HCT, Hispanic patients had a longer initial HCT admission (39 v. 35 days, p< 0.0001) and more frequent readmissions (32% with >2 readmissions in the first year post-HCT v. 25%, p=0.005) compared to NHW patients. Conclusions: HCT is a potentially curative treatment for high-risk acute leukemia; thus the observed racial and SES disparities in receipt of HCT may contribute to disparities in leukemia survival. More detailed disease, treatment, and relapse data would provide a better understanding of the etiology of our findings and allow for reduction of existing disparities through improved access to HCT. Disclosures: Muffly: Servier: Research Funding; Amgen: Consultancy; Adaptive: Research Funding. Wun:Glycomimetics, Inc.: Consultancy.

Background

Black patients with acute myeloid leukemia (AML) are more likely to present with high acuity and consequently experience higher rates of induction mortality than white patients. Given the consistently identified racial disparities in overall survival (OS) among patients with AML, we aimed to evaluate whether there were sustained on-therapy racial differences in inpatient mortality, intensive care unit (ICU) requirements, or supportive care beyond initial induction.

Procedure

Within a retrospective cohort of 1239 children diagnosed with AML between 2004 and 2014 in the Pediatric Health Information System (PHIS) database who survived their initial course of induction chemotherapy, we compared on-therapy inpatient mortality, ICU-level care requirements, treatment course duration, cumulative length of hospital stay (LOS), and resource utilization after induction I by race.

Results

Over the period from the start of induction II through completion of frontline chemotherapy, there were no significant differences in mortality (adjusted odds ratios [OR], 1.01; 95% confidence intervals [CI], 0.41-2.48), ICU-level care requirements (adjusted OR, 0.93; 95% CI, 0.69-1.26), LOS (adjusted mean difference, 3.2 days; 95% CI, -2.3-9.6), or supportive care resource utilization for black patients relative to white patients. Course-specific analyses also demonstrated no differences by race.

Conclusion

Although black patients have higher acuity at presentation and higher induction mortality, such disparities do not persist over subsequent frontline chemotherapy treatment. This finding allows interventions aimed at reducing disparities to be directed at presentation and induction.

Equal access to clinical trial enrollment is important to ensure that findings are generalizable to the broader population. This study aimed to evaluate disparities in enrollment on pediatric oncology clinical trials. We assessed the relationship between patient characteristics and enrollment on COG trial AAML1031 in a cohort of pediatric patients with AML in the Pediatric Health Information System. The associations of enrollment with outcomes were evaluated. Non-Hispanic Black patients, infants, and patients from zip codes with a lower proportion of poverty were less likely to enroll (30% vs. 61%, p = .004; 34% vs. 58%, p = .003; 46% vs. 58%, p = .02). On-therapy mortality was similar among enrolled and nonenrolled patients (7.3% vs. 8.9%, p = .47). Differences in early mortality were more pronounced among nonenrolled patients compared to enrolled patients (3.0% vs. 0.5%, p = .03). Understanding the etiology of these disparities will inform strategies to ensure balanced access to clinical trials across patient populations.

Background

Tetrachloroethene (PCE) is a common environmental and occupational contaminant and an acknowledged neurotoxicant. From 1968 through 1983, widespread contamination of public drinking water supplies with PCE occurred in the Cape Cod region of Massachusetts. The source of the contamination was a vinyl liner applied to the inner surface of water distribution pipes.

Objectives

A retrospective cohort study (the Cape Cod Health Study) was undertaken to examine possible health consequences of early-life exposure to PCE-contaminated drinking water. This review describes the study methods and findings regarding the effects of prenatal and childhood exposure on neurologic outcomes during early adulthood, including vision, neuropsychological functioning, brain structure, risky behaviors, and mental illness. The review also describes the strengths and challenges of conducting population-based epidemiologic research in this unique setting.

Methods

Participants were identified by cross-matching birth certificates and water system data. Information on health outcomes and confounding variables was collected from self-administered surveys (n = 1689), neuropsychological tests (n = 63), vision examinations (n = 63), and magnetic resonance imaging (n = 42). Early-life exposure to PCE was estimated using a leaching and transport model. The data analysis compared the occurrence of each health outcome among individuals with prenatal and early childhood PCE exposure to unexposed individuals while considering the effect of confounding variables.

Findings

The study found evidence that early-life exposure to PCE-contaminated drinking water has long-term neurotoxic effects. The strongest associations were seen with illicit drug use, bipolar disorder, and post-traumatic stress disorder. Key strengths of the study were availability of historical data on affected water systems, a relatively high exposure prevalence and wide range of exposure levels, and little confounding. Challenges arose mainly from the historical nature of the exposure assessments.

Conclusions

The Cape Cod Health Study demonstrates how scientists can take advantage of unique "natural experiments" to learn about the health effects of environmental pollution. This body of work has improved our understanding of the long-term health effects of early-life exposure to this common environmental contaminant and will help risk assessors and policymakers ensure that drinking water supplies in the United States are safe for vulnerable populations.