Real-World Clinical and Economic Outcomes Among Patients With Localized Prostate Cancer Treated With External Beam Radiation Therapy Across Different Risk Stratifications in the United States

Background: External beam radiation therapy (EBRT) is an effective treatment option for patients with localized prostate cancer (LPC). Despite the widespread use of EBRT, evaluation of outcomes based on LPC risk status is limited. Objectives: To comprehensively compare clinical and economic outcomes between patients with high-risk vs low/intermediate-risk LPC following EBRT in real-world United States (US) clinical practice. Methods: This retrospective study used linked patient-level electronic medical record data from PPS Analytics and administrative claims data from the Komodo Research Database (1 January 2016–31 August 2024). Patients with LPC treated with EBRT (date of the first claim was defined as the index date) were identified and stratified into high-risk and low/intermediate-risk cohorts based on clinical guidelines incorporating information based on localized cancer staging, Gleason score, and prostate-specific antigen level. Baseline characteristics were balanced using inverse probability of treatment weighting. A weighted Cox proportional hazards model was used to compare metastasis-free survival (MFS) and event-free survival (EFS) between cohorts. Weighted ordinary least squares regression was used to compare all-cause and PC-related healthcare costs (2024 US dollars), measured per-patient-per-year (PPPY), in the subgroup of patients with continuous insurance eligibility. Results: In total, 5984 and 10 471 patients were included in the high-risk and low/intermediate-risk LPC cohorts, respectively. Patients with low/intermediate-risk vs high-risk LPC had significantly longer MFS (36-month hazard ratio [HR]; 95% confidence interval [CI]: 2.47 [2.15, 2.84], P < .001; 60-month HR: 2.29 [2.05, 2.55], P < .001) and EFS (36-month HR: 1.84 [1.65, 2.06], P < .001; 60-month HR: 1.90 [1.73, 2.08], P < .001). Among the subgroup of patients with continuous insurance eligibility (high-risk: 980 patients; low/intermediate-risk: 1862 patients), patients with high-risk LPC incurred significantly higher mean total all-cause healthcare costs (cost difference [95% CI]: $8269 PPPY [3869, 12 800], P < .001) and mean total PC-related healthcare costs ($9053 PPPY [5232, 13 147], P < .001) post-index compared with those with low/intermediate-risk LPC. Conclusion: Patients with high-risk vs low/intermediate-risk LPC had significantly worse survival outcomes and incurred significantly higher costs following EBRT, consistent with the greater disease burden associated with high-risk disease. More effective treatment strategies are needed to further improve clinical outcomes and reduce economic burden among this patient population.