OBJECTIVES: This research aims to explore metastatic (stage IV) TNBC epidemiology, clinical data, biomarker use, anticancer therapy, Healthcare Resource Utilization (HCRU), cost of healthcare, and Local Burden of Disease (LBD) in adult female population within Costa Rican public health sector.

METHODS:

Study population were patients with metastatic stage TNBC treated during 2019 full year. Data from Costa Rican public health system official and available sources (ICD 10 C 50 encoded records from National Registry of Tumors and National Social Security Fund), as well as local review of the medical literature, were used to estimate metastatic (stage IV) TNBC epidemiology, clinical profile, HCRU, costs of treatments and healthcare tariff. A Delphi Panel of physicians was developed to build the processes of diagnosis, healthcare, and specific treatments of metastatic TNBC. Finally, cost analysis and estimation of the LBD in the Costa Rican National Social Security Fund was performed.

RESULTS:

In 2019 there were 284 incident cases of TNBC (18.38% from total breast cancer), where 27.5% were in. women <50 years. Stage IV represented 8.94% of total incident TNBC (25 cases). Stage IV deaths were 30.9% of all TNBC mortality. Determination of HR and HER2 was carried out in >90% of cases. Other biomarkers were used <10% (BRCA, PD-L1/PD-1, NTRK, MSI-H/dMMR, CK, EGFR). Metastatic stage treatment was anthracyclines as mono drug (25%), anthracyclines+taxanes (25%) and taxanes only (40%). Other drugs were used in ≤10%. Disability Adjusted Life Years (DALYs) per capita estimated for stage IV were 31.70.

CONCLUSIONS: TNBC is a growing disease over time. Its lethality is notorious with an incremental mortality of approximately 15% (stage IV mortality rate of 0.84 x 100 thousand). HR and determination of HER2 are fully available, however other biomarkers are not routinely used.