OBJECTIVES: Characterizing cost of care is necessary to understand the economic burden in patients with metastatic triple negative breast cancer (mTNBC). This study aimed to assess monthly cost and contributing components during treatment for mTNBC.

METHODS: A retrospective electronic health record review of patients with mTNBC from 9 US community oncology practices was conducted. Eligible patients were females age ≥18 diagnosed with mTNBC between 1/1/2010 and 31/1/2016. Mean monthly costs per patient (hospitalization, emergency department (ED), anti-cancer therapy, office visit, procedure, infused supportive care, other drugs) were evaluated for first line (L1) and second line (L2), based on the allowed amount for these services. Generalized linear regression with gamma distribution and log-link function was used to evaluate predictors of monthly cost.

RESULTS: The sample included 608 patients (60.2% White, 33.9% African American, mean age 57.5 years). The cost analysis included 505 treated patients (L1: 42.6% Taxane, 19.0% Platinum, 8.7% Platinum and Taxane, 29.7% Other). The mean monthly cost during L1 (mean duration: 7.2 months; SD=9.2) was $21,912; hospitalization and ED accounted for 50.2% of costs compared to 32.7% for anti-cancer therapy (see poster for resource utilization). Minority race (p<0.001) was associated with higher cost, and age increase was associated with lower cost (p<0.001). Overall, 302 patients progressed to L2 (4.4 months; 4.9). The mean monthly cost ($24,962) distribution was similar to L1 (51.1% vs. 32.0%). As in L1, increasing age was associated with lower cost (p=0.005), and minority race with higher cost (p<0.001).

CONCLUSIONS: The monthly cost of care for patients with mTNBC is high, and >50% of those costs were associated with hospitalization and ED services. Only 32% of cost was attributable to anti-cancer therapy. Age and race were drivers of cost in L1 and L2, indicating greater economic burden in minority patients and younger patients.