The Economic Burden of Metastatic Castration Resistant Prostate Cancer and Skeletal Related Events in Japanese University Hospitals

OBJECTIVE: Although androgen deprivation therapy (ADT) has improved the survival and quality of life of patients with prostate cancer, resistance to treatment inevitably results in transition to a castration resistant state (CRPC) and, in advanced cases, bone metastasis, leading to skeletal related events (SRE). In order to understand the current burden on patients in Japan, there is a need to estimate the healthcare costs of CRPC treatment in current clinical practice. METHODS: This retrospective observational cohort study utilized claims data from 13 national university hospitals through the Platform for Clinical Information Statistical Analysis database. Extracted data included the use of diagnostic tests, the frequency and cost of hospitalizations and outpatient visits, and medication costs, using values from the Healthcare Fee System and the National Health Insurance Drug Price List relative to each observed year. RESULTS: Data were collected from 4001 patients with CRPC, 97% of whom had undergone ADT. Between 2005 and 2016, the mean annualized direct medical cost per patient was ¥739,147 (US$7060), of which 91% was related to medication, 4.8% to laboratory and imaging, 4.1% to radiotherapy, and 0.1% to surgery. A total of 771 (19%) of the 4001 CRPC patients experienced an SRE. Resource utilization was significantly higher (p<0.0001) in patients with SRE than in those without, with mean annualized medication costs per patient of ¥1,074,885 and ¥659,006, respectively, and ¥108,807 and ¥71,392, respectively, for laboratory and imaging. The occurrence of even one SRE led to a significant increase in costs and the use of analgesics, compared to the prior period. CONCLUSIONS: A diagnosis of CRPC is associated with considerable healthcare resource utilization and increased economic burden on patients, which are significantly higher in those with SREs. Treatments that can prevent or delay SREs may help ease this burden, thereby providing cost savings across Japanese healthcare systems.