Population‐level diagnostic and radiation treatment trends of low‐risk prostate cancer

BACKGROUND: Overtreatment of low-risk prostate cancer (PC) undermines screening efforts. Active surveillance is preferred for low-risk PC, but declining treatment may reflect diagnostic or treatment-selection changes. We assessed diagnostic risk-group trends among localized PC and low-risk trends among radiation-treated patients since 2010. METHODS: We analyzed localized PC in Surveillance, Epidemiology, and End Results Program (SEER; 2010-2023); Veterans Affairs (VA; 2010-2024); and Michigan Radiation Oncology Quality Consortium (MROQC; 2021-2025). Low-risk PC was defined as grade group 1, prostate-specific antigen <10 ng/mL, and clinical stage ≤T2a. Diagnosis-based analyses described risk-group trends among all localized PC diagnoses in SEER and VA and treatment among low-risk patients. The primary outcome was the proportion of radiation-treated patients classified as low-risk, evaluated using logistic regression. RESULTS: Among localized PC, low-risk disease at diagnosis declined from 28.8% to 24.0% in SEER and from 32.3% to 21.9% in VA. Among diagnosed low-risk patients, receipt of neither radiation nor prostatectomy increased from 33.6% to 83.4% in SEER and from 51.6% to 96.3% in VA. Among 207,196 patients treated with radiation for localized PC (170,213 SEER; 34,635 VA; and 2348 MROQC), the proportion with low-risk disease declined from 33.7% to 6.5% in SEER, from 22.9% to 2.0% in VA, and remained ≤4.2% in MROQC. Declines persisted after adjustment. CONCLUSION: Since 2010, low-risk PC has become less common at diagnosis, whereas diagnosed low-risk patients increasingly avoid treatment. Radiation for low-risk PC has markedly declined, paralleling surgical trends and reflecting a nationwide shift toward active surveillance.