Purpose: To evaluate whether repeated prostate-specific antigen (PSA) testing influences treatment patterns and healthcare costs for prostate cancer (PCa).Materials and Methods: We analyzed a nationwide insurance cohort of men newly registered with PCa from 2010 to 2020.Patients were classified as PSA-tested (3 tests across 2 years before registration) or PSA non-tested (first PSA test within 3 months before registration).We compared the initial and subsequent treatment patterns between localized and systemic therapies, and per-patient medical expenditures by treatment modality.The analyses focused on 2016 to 2020, when government-set prices stabilized.Primary endpoints were cumulative medical costs and downstream medical utilization patterns.Results: Of the 166,848 men, 26.7% were PSA-tested, 42.2% were non-tested, and 31.1% were undetermined.Localized therapy was more frequent after repeated testing: surgery, 45.6% versus 33.8% (p<0.001);radiotherapy, 17.0% versus 14.9% (p<0.001); and focal therapy, 0.8% versus 0.3% (p<0.001).Systemic therapy predominated without prior testing: hormone therapy, 59.7% versus 42.3% (p<0.001),chemotherapy, 2.7% versus 1.0% (p<0.001), and androgen receptor-targeted agents, 1.4% versus 0.5% (p<0.001).For localized modalities delivered during 2016 to 2020, the per-patient costs of non-robotic surgery and radiation therapy were comparable between the groups.In contrast, expenditures for hormone therapy and androgen receptor-targeted agents were significantly higher in the PSA non-tested group, primarily reflecting a longer treatment duration rather than higher monthly spending.Conclusions: Once national prices stabilized, repeated PSA testing was associated with greater use of localized therapy and lower cumulative spending on prolonged systemic treatment without increasing the costs for localized modalities.
Ko et al. (Thu,) studied this question.