Sociodemographic predictors of patients with brain metastases treated with stereotactic radiosurgery

Background: Patient sociodemographic factors such income, race, health insurance coverage, and rural residence impact a variety of outcomes in patients with cancer. The role of brain metastasis at presentation and its subsequent outcomes have not been well characterized in this patient population. Results: Multivariate analysis revealed that median income lower than $50,000 was associated with higher presenting symptom grade for brain metastasis (mean RTOG grade 1.2 vs 1.0, SE = 0.1, p = 0.04) and higher chronic symptom grade (mean RTOG grade 1.3 vs 0.9, SE = 0.1, p = 0.002). Higher area-level median income was associated with a lower symptom grade at diagnosis of brain metastasis (p = 0.0008) and likelihood of hospitalization (p = 0.004). Other sociodemographic factors were not significantly associated with survival, neurologic death, or patterns of failure after stereotactic radiosurgery for brain metastases. Conclusions: Lower median income was associated with a greater symptom burden at the time of diagnosis and need for hospitalization for patients with brain metastases, suggesting a delayed time to presentation. These differences in symptom burden persisted during treatment. Methods: Between January 2000 and December 2013, we identified 737 patients treated with stereotactic radiosurgery for brain metastases. They were characterized by 4 sociodemographic factors: median income, race, rural-urban residence, and health insurance status. Clinical outcomes included stage at diagnosis, symptom grade at presentation, likelihood of hospitalization from brain metastasis, overall survival, local failure, distant brain failure, and neurologic death. Multivariate cox proportional hazards model for each outcome was performed controlling for age, sex, number of brain metastases, and dose to brain metastases.