Socioeconomic status and incidence of pediatric embryonal tumors in the United States.

Abstract

10036 Background: Of the 13,000 children diagnosed with cancer each year in the United States (US), the embryonal solid tumors, neuroblastoma (NB), retinoblastoma (RB), Wilms tumors (WT), hepatoblastoma (HB), rhabdomyosarcomas (RMS) and germ cell tumors (GCT), account for over 30% of the cases. Social disparities in cancer are well studied for adults, but few studies have focused on children, mostly for leukemia. The aim of this study is to evaluate the differences in incidence of rare cancers according to socioeconomic status (SES). Methods: Cases aged 0-19 were identified from the Surveillance Epidemiology and End Results (SEER) cancer registries from 1992-2009. Using data from the US 2000 Census, the county of residence of the cases was categorized above or below the national average for SES measures including: % persons with< high school education, % persons below poverty, % persons unemployed and % households with > 1 person/room. Age standardized rates per million (ASR), rate ratios (RR) and 95% confidence intervals (CI) were obtained. The findings were validated using cases from the National Program of Cancer Registries (NPCR) from 1999-2009, analyzed with the same SES variables. Results: Among cases identified in SEER, rates of NB and WT are higher in counties with upper SES measures whereas RB and GCT occurred more frequently in counties with lower SES measures. No association was found between SES and rates of HB and RMS. The results were reproducible with NPCR cases. For instance, ASR of NB is lower (SEER: 5.86; NPCR: 7.48) in counties where >19.6% of the population had not completed high school and higher (SEER: 8.41; NPCR: 8.47) in counties where ≤19.6% had not achieved a high school degree. (SEER: RR=0.69; 95%CI=0.62-0.77; NPCR: RR=0.88; 95%CI=0.84-0.93). Analysis of NB rates according to poverty, unemployment and crowding showed consistent results, with higher rates in counties with higher SES. Conclusions: The findings are suggestive of a relation between SES and cancer susceptibility that may be connected to environment and lifestyle. Understanding the role of contributing causes demands further studies to evaluate why cancer rates vary across cultural and ethnic groups as well as the magnitude of specific SE aspects.