Racial disparities in incidence, treatment, and survival in adult brain metastases: a 10-year national database analysis.

Objective: The aim of this study was to assess demographic and racial disparities in incidence, treatment, and survival of adults with metastatic malignancy to the brain.

Methods: Using the Surveillance, Epidemiology, and End Results (SEER) Program database, the authors identified adults with nonprimary brain metastases between 2010 and 2019. Incidence was calculated for all 10 years while data from 2010 to 2014 were used for survival analysis. The primary outcome measure was all-cause mortality within 5 years, assessed by 6-month, 1-year, 2-year, and 5-year survival rates. Chi-square tests of independence and one-way ANOVA were used to compare categorical and continuous measures, respectively, between non-Hispanic White (NHW), Hispanic White (HW), Black, and Asian/Pacific Islander (API) patients. A multivariable Cox proportional hazards model was developed to evaluate the risk of death within 5 years.

Results: A total of 64,690 patient records were identified and analyzed following exclusion based on age (patients > 84 years or < 18 years were excluded), missing race data, and missing survival data. Incidences are reported per 100,000 adults. The incidence of brain metastases increased from 2.59 in 2010 to 2.78 in 2019, with an average 10-year incidence of 2.72. API patients had the highest population-adjusted incidence (3.52), followed by NHW (2.99), Black (2.32), and HW (1.59) patients. Black patients were the most likely to have low income and single status, while API patients were the most likely to have high income and married status. Subsequently, Black patients had the shortest survival time (9.05 months vs 9.19 months for NHW vs 12.93 months for HW vs 15.89 months for API patients, p < 0.001). After controlling for the effect of socioeconomic factors on survival, the multivariable analysis showed that Black (HR 0.91, 95% CI 0.88-0.94), HW (HR 0.73, 95% CI 0.69-0.76), and API (HR 0.69, 95% CI 0.66-0.73) patients all had a survival advantage compared with NHW patients. Surgery also conferred a strong survival advantage (HR 0.47, 95% CI 0.44-0.49).

Conclusions: The incidence of brain metastases has increased slightly between 2010 and 2019, with the highest rate in API patients. Black patients had the lowest survival, potentially due to poor socioeconomic status and lower rates of surgery and chemotherapy. Black patients were the most likely to not be recommended surgery, suggesting a discrepancy in services offered to these patients. More research is warranted to understand the underlying causes of these disparities.