Epidemiology of Metastatic Castration-Resistant Prostate Cancer in Veterans Nationwide

Background: There is limited research on the burden and outcomes of patients diagnosed with metastatic castration-resistant prostate cancer (mCRPC), which may result in limited understanding of the disease and lead to suboptimal disease management. Using a validated algorithm to identify mCRPC disease onset, this study offers the first comprehensive description of mCRPC among veterans nationwide. Methods: The study used data from the Veterans Health Administration’s Corporate Data Warehouse. Participants were identified using the Prostate Datacore, which uses structured data and natural language processing to identify veterans with prostate cancer, metastatic prostate cancer, and mCRPC. We calculated prevalence and age-adjusted incidence rates of mCRPC from 2005 to 2022 and performed Mann-Kendall trend tests to analyze statistical trends within the time series data. We performed a time-to-event analysis to calculate the median time to mCRPC by disease course, as well as a survival analysis from the date of mCRPC diagnosis to death. Results: We identified 44,246 patients with mCRPC. Prevalence, incidence, and survival increased each year, with the highest prevalence in the western United States. In 2022, the age-adjusted incidence rate was 5 per 1,000 prostate cancer cases. Median time to mCRPC from prostate cancer diagnosis was 5.68 years in patients with de novo disease and 10.98 years in patients with disease progression from localized stages. Median overall survival increased from 1.23 years (95% CI, 1.19–1.27) in 2005 to 2011, to 1.75 years (95% CI, 1.70–1.80) in 2012 to 2017, to 2.17 years (95% CI, 2.11–2.22) in 2018 to 2024, and with differences observed across age groups ( P <.05). Trends show increasing age, Charlson comorbidity index score, and body mass index at diagnosis, but decreasing prostate-specific antigen levels per year. Conclusions: This study describes veterans with mCRPC, suggests that survival and diagnostic methods are improving, and emphasizes the need for better disease management strategies to delay progression to and enhance treatment of mCRPC in order to further prolong survival.