Predictors of survival, healthcare resource utilization, and healthcare costs in veterans with non-metastatic castration-resistant prostate cancer

Objectives: The objective of this study was to evaluate the association of prostate-specific antigen doubling time (PSADT) with metastasis-free survival (MFS) and overall survival (OS), and to describe healthcare resource utilization (HRU) and costs among patients with non-metastatic castrate-resistant prostate cancer (nmCRPC) in the Veterans Health Administration setting. Methods and Materials: Patients with nmCRPC were identified from the Veterans Health Administration electronic health record database (1/2007-8/2017). PSADT was categorized as <3 months, 3 to 9 months, 9 to 15 months, >= 15 months, and unknown. MFS and OS were assessed using multivariable Cox proportional hazards regression, including PSADT as a predictor. HRU and costs were described per-patient-per-year (PPPY). Results: Among 12,083 patients in the study, shorter PSADT was associated with shorter MFS and OS (PSADT < 3 months vs. PSADT >= 15 months hazard ratio [HR] [95% confidence interval (CI)] = 0.307 [0.281, 0.335] and 0.371 [0.335, 0.410], respectively). Patients who developed metastasis had a 3-fold higher risk of death compared to those without metastasis (HR [95% CI] = 2.933 [2.763, 3.113]). Mean HRU increased following the onset of nmCRPC and metastatic castrate-resistant prostate cancer (mCRPC); mean inpatient stays more than doubled (0.2 vs. 0.5 and 0.6 vs. 2.8 PPPY, respectively). Similar increases in healthcare costs were observed; pharmacy costs more than tripled following nmCRPC ($2,074 vs. $6,839 PPPY). From nmCRPC to mCRPC, large increases were observed for inpatient costs ($7,257-$ 61,691), emergency room costs ($844-$ 1,958), and pharmacy costs ($4,115-$ 26,279) PPPY. Conclusions: In Veterans with nmCRPC, shorter PSADT was significantly associated with shorter MFS and OS. Onset of nmCRPC and mCRPC was associated with substantial HRU and cost increases. (C) 2020 Elsevier Inc. All rights reserved.