The impact of socioeconomic status on overall survival in patients at a radiation oncology center: A retrospective study.

147 Background: There are few reports examining the impact of socioeconomic status (SES), as indicated by the Area Deprivation Index (ADI), on overall survival (OS) in radiation oncology patients, making this an important area of investigation. This study aims to investigate the influence of ADI on OS in radiation oncology patients, while controlling for stage and other relevant variables. Methods: This retrospective study analyzed data from radiation oncology patients treated at a large multi-site single-institution center from October 2006 to January 2024. Demographic and treatment information, including age, gender, race, insurance status, comorbidity index (CCI), mental health disorders (MHD), treatment intent, cancer type, and stage, were collected. The ADI was used to measure SES and was gathered from the Neighborhood Atlas. Kaplan-Meier curves were generated for all patients, with separate curves for different cancer types. The impact of demographic, clinical, and socioeconomic factors on OS was assessed using a Cox proportional hazards multivariable (MVA) logistic regression analysis. The model was stratified by treatment intent, cancer type, stage, insurance status, and CCI. Results: In this comprehensive analysis of 7343 patients, the median follow-up was 12.00 months (IQR: 1.8–36.82). Most patients were breast cancer (30.2%), over 65 years old (60.5%), and had an ADI below the mean (55.5%), indicating lower socioeconomic disadvantage. Kaplan-Meier analysis showed that 5-year OS rates were significantly lower for the fourth quartile ADI group (85.1%) compared to the first quartile ADI group (94.0%) (p<0.001). Among different cancer types, significant differences in OS were observed for breast cancer (p=0.002) and miscellaneous (uncategorized) cancers (p=0.005), with lung cancer showing a trend towards significance (p=0.053). The MVA revealed that patients in both the third quartile (hazard ratio (HR)=1.343, 95% CI: 1.029–1.752, p=0.030) and fourth quartile (HR=1.403, 95% CI: 1.075–1.829, p=0.013) of ADI had significantly higher likelihood of mortality compared to those in the first ADI quartile. Conclusions: SES, as measured by ADI, significantly impacts OS in radiation oncology patients. Poorer patients, indicated by higher ADI, exhibited worse survival outcomes despite controlling for cancer type, stage, treatment intent, CCI, MHD, and insurance status. These findings underscore the need for targeted interventions to address socioeconomic disparities in cancer care to improve survival outcomes for disadvantaged populations.