Socioeconomic status variables contribute to the disparities in female triple negative breast cancer outcome in the United States, 2011-2015: A population study based on NCI Surveillance, Epidemiology and End Results (SEER) database.

Abstract

6521 Background: Cancer disparities pertinent to socioeconomic status (SES) still exist in the American healthcare system. How SES variables impact the outcome of triple negative breast cancer (TNBC) needs identification. Methods: We enrolled 22,434 women diagnosed with invasive TNBC in 2011 – 2015 from the SEER 18 program. The primary outcome was to identify SES risk factors for TNBC cause specific survival (TNBCCSS)and overall survival (OS) via the Cox Proportional Hazard Regression Model. SES information was collected: race, insurance status, marital status, and percentage of families with incomes below the poverty level and adults with less than high school graduate (<HSG) in a county of the patient’s residency; all analyses were also adjusted for clinicopathological characteristics. We categorized rates of poverty and <HSG as quartiles. Results: 18,578 (82.8%) women were insured or insured/ no specifics (NS), and 3,360 (15.0%) received Medicaid upon TNBC diagnosis; only 496 (2.2%) patients were uninsured. The TNBCCSS rates of insured, insured/ NS, Medicaid, and uninsured cohorts were 86.6%, 83.6%, 77.4% and 73.2%, respectively. In multivariable adjusted analyses, the TNBC cause specific mortality risk of patients who were uninsured or receiving Medicaid was significantly higher than that of women who were insured (Hazard ratio [HR] = 1.60, 95% confidence interval [CI]: 1.34-1.92 and HR = 1.29, 95% CI: 1.18-1.41, respectively). Women residing in a county with a high poverty rate (the 3rd quartile [rate of 11.1 – <14.3%]) had significantly worse TNBC cause specific mortality risk as compared to women with residency of the lowest poverty rate (HR = 1.25, 95% CI: 1.10-1.41). Single and widowed cohorts had better HR of TNBCCSS compared with the married population (HR = 0.86, 95% CI: 0.79-0.95 and HR = 0.82, 95% CI: 0.73-0.93, respectively). Notably, we observed a synergistic effect among race, insurance status and TNBC OS: black women receiving Medicaid had significantly lower HR compared with their non-Hispanic white counterparts (HR = 0.86, 95% CI: 0.74-0.98). Rate of <HSG was marginally correlated with the TNBCCSS. Conclusions: SES variables contribute to the disparities in TNBC survival. TNBC cause specific mortality risk of patients without insurance or with Medicaid at the time of TNBC diagnosis is 60% and 29% higher compared with insured women (Table). Race and insurance status act synergistically upon TNBC OS.[Table: see text]