OBJECTIVES: Disease management costs by health state, which are important in economic modeling, were not well studied in post-nephrectomy renal cell carcinoma (RCC). This study aims to assess the disease management costs by RCC health state post-nephrectomy, including disease-free (DF), locoregional recurrence (LR), distant metastasis (DM), and death.

METHODS: The SEER-Medicare database (2007–2016) was used to identify patients with newly diagnosed, post-nephrectomy, non-metastatic, intermediate-high or high risk RCC. All-cause healthcare costs from Medicare claims, excluding RCC-specific drug and administration costs, were used to estimate per-patient-per-month (PPPM) disease management costs (2019 USD). Costs incurred in DF state were summed up and averaged over time (years 1-3, 4-5, and 6+) from initial nephrectomy until any recurrence or 30-day before death. Monthly average costs in LR state were calculated using accumulated costs from LR until DM or 30-day before death; costs of nephrectomy in LR were estimated separately. Costs for DM were broken down by pre-progression and post-progression. Terminal care costs were estimated as costs incurred during the 30-day before death.

RESULTS: The mean PPPM disease management costs are $1,942 for DF state (years 1-3), $3,071 for LR, $5,029 for DM pre-progression (month 2+) and $6,536 post-progression, and $16,309 for terminal care. Within a health state, costs are decreasing over time: the mean PPPM costs for DF state in years 4-5 and years 6+ are $1,318 and $1,219, respectively; for DM pre-progression, the costs are $12,756 in month 1. Costs for nephrectomy procedure in LR are $20,249.

CONCLUSIONS: Post-nephrectomy RCC at later stages has higher disease management costs than at earlier stages. Adjuvant therapies that could help maintaining patients in DF state may decrease disease management costs among this patient population. Additionally, future studies evaluating the economic impact of new treatment should account for the observed time-varying pattern of disease management costs within a state.