Unveiling the chasm of economic burden from metastatic prostate cancer through a nationwide retrospective cohort study.

Objective: To analyze the clinical and economic consequences of the progression to castration-resistant status for patients with metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC) in South Korea.

Methods: This retrospective cohort study was conducted using National Health Insurance claims data from 2013 to 2021. Patients defined as newly diagnosed with mHSPC had an index date of first claim for metastatic PC between 2015 and 2016 and no exposure to CRPC medicines during the washout period. All-cause monthly medical and end-of-life costs were described for mHSPC and mCRPC. Descriptive statistics were used to analyze medical costs, and generalized estimating equations were used to evaluate the correlation between medical costs and significant variables, including disease progression, death, and clinical characteristics.

Results: Of the 3,739 patients with mHSPC included (mean 72.9 years), 779 progressed to mCRPC. The overall study population underwent a median 60.48-month follow-up period. The average monthly medical cost depending on CRPC progression was 1.5 times higher in the mCRPC than in the mHSPC group ($1,734.2 vs. $1,185.4). Monthly medical costs for those who progressed to mCRPC were 2.4 times higher one year after progression than one year before. In all groups, the average total medical costs gradually increased near mortality. Disease progression and death had a significant correlation with medical costs, by 1.7 times and 2.46 times, respectively.

Conclusion: This study highlights the economic and health benefits of preventing progression to castration resistance in patients with mHSPC based on real-world data.