The economic impact of disease progression and death in hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer patients: using Korean nationwide health insurance claims data.

Objectives: Recognizing the value of anticancer treatments based on progression-free survival and overall survival may help decision making in healthcare policy. We aimed to measure and compare the impact of disease progression and terminal state prior to death on healthcare costs in HR+, HER2- ABC patients.Methods: We conducted a retrospective study using Korean nationwide health insurance claims database between 9/1/2012-8/31/2017. The impact of disease progression was estimated by measuring the average incremental monthly cost per patient during 1 year after progression compared to 1 year before progression. Death-related costs per patient per month (PPPM) were measured for those who died within 1 year after progression. Generalized estimating equation (GEE) was used to estimate the variations in PPPM costs by progression and death with adjustment for clinical factors.Results: After progression, 1,636 patients expensed $2,892 per month more on average than before progression ($3,762 vs. $870). The GEE analysis with adjustment for baseline characteristics showed that PPPM costs increased by 3.46 folds (95% CI =3.06-3.93) after progression. Also, PPPM costs were 1.74 (95%CI =1.43-2.12) times higher in patients who died within 1 year after progression relative to survived patients. When considering the interaction between progression and death, deceased patients showed higher increased ratio of PPPM costs after progression (4.91; p = value <0.0001) than survived patients (2.95; 95% CI =2.61-3.34).Conclusions: From the payer's perspective, more healthcare costs incurred during the progression state than terminal state in HR+, HER2- ABC patients. The impact of disease progression emphasizes the importance of effectively treating HR+, HER2- ABC patients.