Using magnetic resonance imaging (MRI) for prostate cancer screening may aid early detection of clinically significant disease, especially when a man’s screening PSA level is less than 3 ng/mL, investigators report.

“Prostate MRI may have value in screening independently of PSA,” Caroline Moore, MBBS, of the University College London in London, UK, and colleagues wrote in BMJ Oncology.

For the REIMAGINE study (Clinicaltrials.gov NCT04063566) the investigators tested an age-based vs PSA-based approach to MRI screening. They randomly invited men aged 50-75 years from UK general practices to receive a prostate health check including both a screening MRI and a PSA test.

Among 303 completers, 48 men (16%) had a positive screening MRI, including 32 men (67%) who had PSA levels lower than the 3 ng/mL threshold for prostate biopsy used in the European Randomised Screening for Prostate Cancer study. An additional 16 men (5%) only had an abnormal PSA screening (defined as a PSA density of 0.12 ng/mL² or greater), including 3 men with a PSA less than 3 ng/mL; of this group, 4 men had clinically significant cancer.

Targeted and systematic transperineal biopsy (indicated after multiparametric MRI) revealed clinically significant prostate cancer in 29 men (9.6%), including 15 men who had a PSA of less than 3 ng/mL. Only 1% overall were overdiagnosed with insignificant cancer.

“In clinical practice, we recognise that the PSA test has limitations in the identification of men at risk for prostate cancer,” the authors wrote. “MRI may allow us an alternative way to assess prostate cancer risk in men in the community. Normative data on the prevalence of MRI lesions in an age-defined systematically recruited community-based population has not been previously reported.”

In a news release from University College London, Dr Moore commented, “The thought that over half the men with clinically significant cancer had a PSA less than 3 ng/mL and would have been reassured that they didn’t have cancer by a PSA test alone is a sobering one and reiterates the need to consider a new approach to prostate cancer screening.”

The investigators also noted that Black men responded to the screening invitation letter at one fifth the rate of White men, suggesting that innovative strategies are needed to reach this population. The ongoing LIMIT trial is attempting to recruit more Black men.

The UK currently does not have a formal prostate cancer screening program. The prostate cancer death rate in the UK is higher than in the US: 12.4 vs 8.2 per 100,000 population.

In an accompanying editorial, Peter Albertsen, MD, of UConn Health in Farmington, Connecticut, discussed outstanding questions in the efforts to optimize prostate cancer screening, such as when should MRI and/or PSA testing start and stop.

“Ultimately, any screening programme must meet public health criteria that balance the economic cost and the impact on quality of life against the potential gain in increased life expectancy,” he wrote. “The natural history of most screen-detected prostate cancers extends well over a decade. This is a long time to validate a screening protocol, but necessary to prove its value.”

References

Moore CM, Frangou E, McCartan N, et al. Prevalence of MRI lesions in men responding to a GP-led invitation for a prostate health check: a prospective cohort study. BMJ Oncol. Published online August 22, 2023. doi:10.1136/bmjonc-2023-000057

MRI scans improve prostate cancer diagnosis in screening trial. News release. University College London; August 22, 2023.

Albertsen P. Can PSA testing become appropriate public health policy? BMJ Oncol. Published online August 22, 2023. doi:10.1136/bmjonc-2023-000168