The Mediating Effect of Socioeconomic Status and Persistent Poverty on Racial and Ethnic Disparities in Pediatric Cancer Mortality in the United States

BACKGROUND: Socioeconomic (SE) factors have been shown to mediate racial and ethnic disparities in adult cancer mortality. However, evidence in pediatric cancer is limited, especially at finer geographic levels. OBJECTIVE: Evaluate the mediating effect of socioeconomic status (SES) and persistent poverty in racial and ethnic disparities in childhood cancer mortality using census tract-level data. METHODS: Data were obtained from the 2006-2020 SEER Incidence Data with Census Tract Attributes Database and included children 0-19 years. Neighborhood-level SES was measured using a composite variable with five categories. Census tracts were classified as persistently poor if 20% or more of the population lived below the poverty level for 30 years. Cause-specific Cox proportional-hazard models were used to examine the association of race and ethnicity with cancer mortality, adjusting for age, gender, stage at diagnosis, cancer type, and rurality. A weighted approach mediation analysis was performed in R4.1.3. RESULTS: Among 96,665 included cases, 19.95% of children lived in the lowest SES quintile, and 12.23% lived in areas with persistent poverty. The distribution of SES and persistent poverty varied across race and ethnicity. Specifically, 9.79% of White children lived in the lowest SES neighborhoods compared to 33.77% of Black and 32.48% of Hispanic children. In addition, 4.83% of White children lived in persistent poverty compared to 21.38% of Black and 21.30% of Hispanic children. Compared to White children, the risk of cancer death was higher among Black (aHR: 1.53; 95% CI: 1.45-1.62), Hispanic (aHR: 1.17; 95% CI: 1.12-1.22), and Asian (aHR: 1.24; 95% 1.15-1.33) children. The proportion mediated by SES was 13.50% for Black, 29.3% for Hispanic, and 37.58% among AI/AN children. The proportion mediated by persistent poverty was 6% for Black, 12.79% for Hispanic, and 17.47% for AI/AN children. CONCLUSION: SES and persistent poverty significantly contributed to racial and ethnic differences in pediatric cancer mortality.