| アブストラクト | BACKGROUND AND OBJECTIVES: Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) are standard first-line treatment for hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer, yet the cost architecture across the full treatment trajectory remains poorly characterized. This study aimed to characterize phase-specific healthcare costs using a Japanese nationwide claims database. METHODS: We conducted a retrospective cohort study using the DeSC-IQVIA integrated Claims data (April 2014-May 2025). Patients with HR+/HER2- metastatic breast cancer who initiated first-line CDK4/6i were identified. Healthcare costs were decomposed into drug, non-drug inpatient, and non-drug outpatient components across eight treatment phases. Death-anchored analysis evaluated cost structure over the final 12 months of life among decedents. RESULTS: Among 5435 patients (median age 72.3 years), active treatment phases showed drug-dominated cost structures: first-line per-patient per-month (PPPM) cost was 482,936 Japanese yen (JPY) (drug 85%-90%), second-line 361,615 JPY (81%), and extended chemotherapy 255,922 JPY (66%). A marked inversion occurred in the palliative phase (PPPM 233,824 JPY; drug 11%, inpatient 70%) and terminal phase (PPPM 412,149 JPY; drug 17%, inpatient 69%). Death-anchored analysis of 1111 decedents identified a transition 2 months before death, when inpatient costs first exceeded drug costs. Individual fixed-effects models estimated the CDK4/6i-associated cost increment at 239,815 JPY/month (p < 0.001), corresponding to a total treatment-associated cost of 2.99 million JPY per patient. CONCLUSIONS: The cost architecture of CDK4/6i-treated metastatic breast cancer follows a predictable trajectory from drug-dominated active treatment to hospitalization-dominated end-of-life care, with a structural transition approximately 2 months before death. These findings support phase-specific healthcare resource allocation and economic modeling. |
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| ジャーナル名 | Clinical drug investigation |
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| Pubmed追加日 | 2026/9/29 |
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| 投稿者 | Kashiwa, Munenobu; Moriwaki, Kensuke |
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| 組織名 | Comprehensive Unit for Health Economic Evidence Review and Decision Support;(CHEERS), Research Organization of Science and Technology, Ritsumeikan;University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan.;mkashiwa@fc.ritsumei.ac.jp.;Division of Health Policy and Management, Department of Biomedical Science,;College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu,;Shiga, 525-8577, Japan. |
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| Pubmed リンク | https://www.ncbi.nlm.nih.gov/pubmed/42806185/ |
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