Socioeconomic Disparities in Brain Metastasis Survival and Treatment: A Population-Based Study

OBJECTIVE: in the present study, we used a validated socioeconomic status (SES) index and population-based registry to identify and quantify the impact of SES on access to treatment and overall survival for patients diagnosed with synchronous brain metastases. METHODS: The Surveillance, Epidemiology, and End Results database was used to extract all patients between 2010 and 2016 with brain metastases at initial presentation. SES was stratified into tertiles and quintiles using the validated Yost index. Multivariable logistic regressions were used to evaluate the impact of demographic, tumor, and socioeconomic covariates on receipt of radiotherapy and chemotherapy. Kaplan-Meier curves were used to estimate survival. RESULTS: Between 2010 and 2016, 35,595 patients presented with brain metastases at the time of primary cancer diagnosis. Most patients received radiation and/or chemotherapy as part of the initial course of their treatment; 71.6% (n = 25,484) were irradiated while 54.4% (n = 19,371) received chemotherapy and 44.9% (n = 15,984) received chemoradiation. Patients in the highest Yost tertile and quintile experienced longer overall survival (P < 0.001). Additionally, multivariable logistic regression revealed that the lowest Yost quintile was significantly less likely to receive either radiation (adjusted OR: 0.82; 95% confidence interval: 0.75-0.89; P < 0.001) or chemotherapy (adjusted OR: 0.62; 95% confidence interval: 0.58-0.67; P < 0.001). CONCLUSIONS: In a large, population-based analysis of brain metastasis patients, we found significant differences in treatment access and mild survival differences along socioeconomic strata. More specifically, patients in lower SES tiers suffered worse outcomes and received radiation and chemotherapy less frequently than patients in higher tiers, even after accounting for other tumor- and demographic-related information.