Pediatric Renal Cell Carcinoma (pRCC) Subpopulation Environmental Differentials in Survival Disadvantage of Black/African American Children in the United States: Large-Cohort Evidence.

OBJECTIVE

Renal cell carcinoma (RCC) is a rare but severe and aggressive pediatric malignancy. While incidence is uncommon, survival is relatively low with respect to acute lymphocytic leukemia (ALL), AML, lymphoma, ependymoma, glioblastoma, and Wilms Tumor. The pediatric renal cell carcinoma (pRCC) incidence, cumulative incidence (period prevalence), and mortality vary by health disparities' indicators, namely sex, race, ethnicity, age at tumor diagnosis, and social determinants of health (SDHs) as well as Epigenomic Determinants of Health (EDHs). However, studies are unavailable on some pRCC risk determinants, such as area of residence and socio-economic status (SES). The current study aimed at assessing the temporal trends, cumulative incidence, household median income, urbanity, mortality, and pRCC survival differentials.

MATERIALS AND METHODS

A retrospective cohort design was utilized to examine the event-free survival of children (0-19) with RCC using the Surveillance Epidemiology and End Result Data, 1973-2015. While the time-dependent variable, namely survival months, was utilized, we assessed the predictors of pRCC survival, mainly sex, age at diagnosis, education, insurance status, income, and tumor grade, as prognostic factors. In examining the joint effect of area of residence and race, as an exposure function with time in survival, we utilized the Cox proportional hazard model, while the annual percent change was assessed using a generalized linear model, implying a weighted average.

RESULTS

Between 1973 and 2015, there were 174 cases of pRCC, of whom 49 experienced mortality (28.2%). The pRCC cumulative incidence tends to increase with advancing age. A significant survival differential was observed between black/AA children with RCC and their white counterparts. Compared with white children, black/AA children were almost three times as likely to die, hazard ratio (HR) = 2.90, 95% CI = 1.56-5.31, = 0.001. A survival differential was observed in sex, with males presenting with a 21% increased likelihood of dying, HR = 1.21; 95% CI, 0.69-2.11. In the metropolitan area, the risk of dying was almost three times as likely among black/AA children compared to their white counterparts, HR = 2.78; 95% CI, 1.45-5.43, while in the urban area, the risk of dying was almost four times as likely among black/AA children compared to their white counterparts, HR = 4.18; 95% CI, 0.84-20.80. After controlling for age, sex, education, and insurance, the risk of dying increased amongst black/AA children in metropolitan areas, adjusted HR (aHR) = 3.37, 99% CI = 1.35-8.44. In the urban area, after adjustment for age, sex, and insurance, there was an increased risk of dying for black/AA children, compared with their white counterparts with pRCC, aHR = 8.87, 99% CI = 2.77-28.10.

CONCLUSION

pRCC indicates an increased trend in males and age at diagnosis between 10 and 14, as well as a survival disadvantage among black/AA children, compared with their white counterparts. Additionally, urbanity significantly influences the racial differences in survival. These data are suggestive of the conjoined effect of environment and race in pRCC survival, indicative of further assessment of gene-environment interaction (epigenomics) in incidence, mortality, and survival in pRCC.