Palliative Care Use Trends, Racial/Ethnic Disparities, and Overall Survival Differences Among Patients With Metastatic Breast Cancer.

Background: Palliative care improves cancer patients' quality of life. Limited research has investigated racial/ethnic disparities in palliative care utilization and its associated survival among metastatic breast cancer (MBC) patients. Objectives: To examine racial/ethnic palliative care use disparities and assess racial/ethnic overall survival differences in MBC patients stratified by palliative care use. Design: A retrospective study of MBC patients from the 2004-2020 National Cancer Database. Measurements: Palliative care was defined as noncurative cancer treatment, including surgery, radiotherapy, systemic therapy, and/or pain management; utilization was coded "yes/no." Racial/ethnic groups included Asian, American Indian or Alaska Native (AIAN), Black, Hawaiian or Other Pacific Islander (HPI), Hispanic, and White. Logistic regression was performed to assess palliative care use disparities. Overall survival was modeled using Cox regression. Results: Of 148,931 patients, the mean age was 62 years; 99% were female; 73% identified as White, 17% as Black, 6% as Hispanic, 3% as Asian, 0.3% as AIAN, and 0.3% as HPI; 42% and 39% had Medicare and private insurance, respectively. Overall, 21% used palliative care, with an increasing utilization rate from 2004 to 2020 (3.6% increase per year, p-trend <0.001). Black (adjusted odds ratio [aOR] = 0.89; 95% confidence interval [CI]: 0.84 to 0.94), Asian (aOR = 0.76; 95% CI: 0.68 to 0.86), and Hispanic (aOR = 0.68; 95% CI: 0.62 to 0.74) patients had a lower likelihood of palliative care utilization than White patients. Among palliative care users, compared with White patients, Black (adjusted hazard ratio [aHR] = 1.14, 95% CI: 1.07 to 1.21) patients had a greater mortality risk, while Asian (aHR = 0.83, 95% CI: 0.71 to 0.97) and Hispanic (aHR = 0.77, 95% CI: 0.69 to 0.87) patients had a lower mortality risk. Conclusions: Palliative care utilization among MBC patients significantly increased but remained suboptimal. Racial/ethnic minority patients were less likely to use palliative care, and Black patients had worse survival, than White patients, suggesting the need for improving palliative care access and ameliorating disparities in MBC patients.