The Role of Socioeconomic Status (SES) in Disease Outcomes in Pediatric Cancer Patients Receiving Proton Therapy

Abstract

Social factors are known to play a critical role in disease burden and socioeconomic status (SES) has been associated with several health conditions and outcomes. There is strong evidence that SES plays an important role in the incidence, morbidity and mortality of cancer within the adult population, but the impact of SES within the pediatric cancer population is still under debate due to conflicting results. Here we use the large multicenter Pediatric Proton/Photon Consortium Registry (PPCR) to investigate how SES can affect disease control and other outcomes in patients treated for pediatric cancers at proton therapy centers across the United States. All patients were enrolled in the PPCR from October 2012 – August 2015 and received radiation. Home addresses, progression free survival (PFS) and overall survival (OS) were extracted from the PPCR for socioeconomic analysis. Their zip code (ZC) and census tract (CT), two different enumeration areas, were established using their home address and zip code, if provided. CT is much smaller than ZC. The American Community Survey from the US Bureau of Labor Statistics was used to extract median income, attainment of high school diploma, and percentage of population below the poverty line for the enumeration area corresponding to the patient’s address and zip code. All data was analyzed using SAS. Two-sided hypothesis testing was used, where p-value < 0.05 was considered significant. Correlation between data at ZC and CT level was assessed using Spearman and Pearson correlations. 876 patients with pediatric cancer were enrolled in the PPCR during this time. International patients and those with no address were excluded, leaving 637 patients for analysis. Mean median income was $67,639 at ZC level and $70,906 at CT level. Mean rate of high school graduation was 89.0% at ZC level and 89.1% at CT level. Mean rate below poverty line was 12.3% at ZC level and 11.7% at CT level. There was no significant difference between data obtained at ZC and CT levels for all metrics. No significant difference was found in OS or PFS (p-value 0.49 and 0.65) as a function of median income, or by poverty status (p-value 0.94 and 0.88). There is no significant difference in OS or PFS with attainment of high school diploma (p-value 0.51 and 0.65). Within the population of patients with pediatric cancer treated with proton therapy, population socioeconomic factors including median income, attainment of high school diplomas and rate of poverty have not been shown to significantly impact OS or PFS. Importantly, results do not vary when taken at two different enumeration areas.Tabled 1Abstract 2958; TableMeasureZC levelCT levelCorrelationsMean95% CIMean95% CIPearsonSpearmanMedian Income ($)67,63911,691.71 – 123,586.0670,9065,143.25 – 136,368.550.8550.838High school graduation (%)89.0272.95 – 10089.0870.63 – 1000.8540.821Rate below poverty (%)12.330 – 30.7811.740 – 32.160.730.776 Open table in a new tab