OBJECTIVES: HER2+ breast cancer (BC), a mayor health concern in the Dominican Republic (DR), accounted 3,412 new cases in 2020, representing 33.64% of female cancers. This study aims to estimate the economic burden of this type of cancer and analyze the epidemiological and cost impact of HER2+ targeted therapies.

METHODS: A Panel Delphi, bottom-up cost analysis was conducted with 11 oncologists from DR, to determine the real-world HER2+ breast cancer patient management. The oncologists represent both public and private healthcare systems in Santiago and Santo Domingo (principal cities in DR). These experts evaluate the probability and frequency of resource usage, to determine the difference within management and healthcare systems (reduce halo effect). The HER2+ BC management costs (USD2023) were obtained by public purchase history, expert reports and specialty pharmacies. Also, a population estimation model was performed to determine the impact of targeted HER2+ therapies in BC avoided relapses, prevented metastases, life years (LYs) gained, quality-adjusted life years (QALYs), and metastatic BC cost reduction, comparing a base scenario (chemotherapy alone) vs actual scenario (Chemotherapy & Trastuzumab) vs ideal one (Chemotherapy, Trastuzumab, Pertuzumab & Trastuzumab+Emtansine).

RESULTS: The average-annual-cost of healthcare for a patient with HER2+ BC (actual scenario) in neoadyuvance, adyuvance and metastases in 1st & 2nd line is USD48,963.38, USD48,827.63, USD71,012.30, USD57,495.06; respectively. The disease-targeted therapies in the actual and ideal scenario for DR in 2023 vs chemotherapy alone impact respectively, 32 & 59 recurrences avoided, 29 & 54 metastases prevented, 860 & 1569 LYs gained, 682 & 1243 QALYs gained, and USD4,363,251 & USD7,959,759 saved.

CONCLUSIONS: The treatment of HER2+ BC in DR is more expensive in the metastatic stages than in neo-adyuvance or adyuvance stages, the use of targeted therapies helps to improve patient’s health, avoid metastases, gain LYs & QALYs, and save money from the metastases avoided.