For years, clinical guidelines warned of a quiet, persistent excess in American medicine: men diagnosed with low-risk prostate cancer were frequently undergoing aggressive treatments they didn’t necessarily need. Radiation therapy and surgery carried side effects like incontinence and erectile dysfunction, often deployed against tumors that might never have threatened a patient’s life.
That pattern is finally shifting in a measurable way. A retrospective cohort study published online October 26 in Cancer by Dr. Steven M. Monda and his colleagues at the University of Michigan Department of Urology reveals that the proportion of radiation-treated prostate cancer patients with low-risk disease has dropped sharply across major US health systems, Medscape reported.
Among patients receiving radiation for localized prostate cancer, those with low-risk disease declined more than 5-fold from 2010 to 2023 in the Surveillance, Epidemiology, and End Results (SEER) registries. In the Veterans Affairs (VA) health system, that decline was even steeper, falling more than 10-fold between 2010 and 2024.
To capture these shifts, researchers examined three distinct cohorts: 546,343 SEER patients and 170,487 VA patients in diagnosis-based analyses, alongside 207,196 radiation-treated patients drawn from SEER, the VA, and the Michigan Radiation Oncology Quality Consortium (MROQC) facilities across Michigan between 2021 and 2025. Low-risk prostate cancer was strictly defined across the datasets as grade group 1, a prostate-specific antigen (PSA) level under 10 ng/mL, and a clinical stage of T2a or lower.
The data show that overall diagnoses of low-risk disease also contracted over the study period. The proportion of localized diagnoses classified as low risk fell from 32.3% to 21.9% in the VA, and from 28.8% to 24.0% in SEER. Meanwhile, among patients who actually received a low-risk diagnosis, the likelihood of avoiding immediate intervention entirely rose significantly. The proportion receiving neither radiation nor prostatectomy within one year increased about 2.5-fold in SEER—moving from 33.6% to 83.4%—and nearly doubled in the VA, climbing from 51.6% to 96.3%.
Shifting Radiation Trends Across Cohorts
When looking exclusively at the subset of 207,196 patients who did undergo radiation therapy, the drop in low-risk cases was stark. In SEER, the share plummeted from 33.7% down to 6.5%. In the VA system, it fell from 22.9% to 2.0%. Meanwhile, MROQC data showed low-risk radiation rates remaining low at 4.2% or below, with no significant statistical association between the treatment year and the presence of low-risk disease during its active observation window.
Age emerged as a notable factor in these treatment decisions. Older age was consistently associated with lower odds of receiving radiation among low-risk patients, reflected by an odds ratio per 5-year increase of 0.70 in SEER, 0.70 in the VA, and 0.77 in MROQC, with all values registering a statistical significance of $P < .001$.
“Demonstrating that modern practice patterns substantially limit overtreatment despite ongoing diagnosis of low-risk disease strengthens the argument that early detection can be pursued with less risk of unnecessary therapy,” the study authors wrote in Cancer.
Despite the encouraging reduction in overtreatment, researchers acknowledged inherent limitations in their design. Relying exclusively on standard risk groups to define overtreatment can overlook critical individual variables, such as a patient’s overall life expectancy, competing health risks, and the unique underlying biology of the tumor. SEER clinical T-stages were not reliably accessible for surgical patients in certain diagnosis years, requiring researchers to omit T-stage from the risk-group assignment during diagnosis-based analysis. Registry codes carry baseline limitations, and both MROQC and the VA recorded fewer cases in later years, which can affect the overall stability of the estimates.
Funding for the study came from the National Institutes of Health/National Cancer Institute, the Agency for Healthcare Research and Quality, the Blue Cross Blue Shield of Michigan Foundation, and the BCBSM Value Partnerships Program. Several study authors disclosed consulting fees, research support, or advisory roles with various pharmaceutical and medical device companies, including Janssen, Merck, Pfizer, and Johnson & Johnson.
