Health UK (Commonwealth Union) – New research conducted collaboratively by the University College London (UCL), University College London Hospitals, (UCLH), and King’s College London has revealed that incorporating MRI as a screening method alongside PSA density enables the detection of cancer cases that would have gone unnoticed by relying solely on the blood test. The findings of the REIMAGINE study, published in BMJ Oncology, represent a pioneering effort to utilize MRI scans in conjunction with prostate-specific antigen (PSA) density measurements to evaluate the necessity for further standard NHS tests. Out of the 29 participants diagnosed with significant prostate cancer, 15 had initially shown a ‘low’ PSA score, which, under the current protocol, would not have prompted further investigation.
As per the current system, men aged over 50 in the UK can request a PSA test if they are displaying symptoms or hold concerns regarding prostate cancer. Earlier screening studies employed a PSA level of 3ng/ml or above as the threshold for initiating supplementary tests, such as biopsies, to identify prostate cancer, as indicated by researchers.
While previous research established that a combination of PSA testing and/or digital rectal examinations, followed by biopsies if suspicion of disease arises, contributed to a 20% reduction in prostate cancer mortality over a 16-year period, this approach has also been linked to the overdiagnosis and excessive treatment of lower-risk cancers.
In recent years, the integration of MRI as the initial step in assessing men at higher risk of prostate cancer has spared one out of four men from unnecessary biopsies, which can be invasive and entail complications.
The study envisions that introducing MRI as a screening tool offered proactively, without necessitating individual requests, could further decrease prostate cancer mortality rates and reduce instances of overtreatment.
In the study’s design, researchers extended invitations to men aged 50 to 75 for a screening MRI and PSA test. Out of the 303 men who completed both tests, 48 (16%) received positive screening MRI results suggestive of possible cancer, despite having a median PSA density reading of 1.2 ng/ml. Among these individuals, 32 had PSA levels below the current benchmark of 3ng/ml used in screening, indicating they would not have been referred for further assessment under the current PSA-based protocol.
Subsequent to an assessment within the NHS, 29 men (9.6%) received a cancer diagnosis necessitating treatment, including 15 with severe cancer and PSA levels below 3ng/ml. An additional three men (1%) were diagnosed with low-risk cancer that did not warrant treatment.
Professor Caroline Moore of the UCL Surgical & Interventional Science and consultant surgeon at UCLH, as well as chief investigator of the study and NIHR Research Professor, says “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. Our results give an early indication that MRI could offer a more reliable method of detecting potentially serious cancers early, with the added benefit that less than one per cent of participants were ‘over-diagnosed’ with low-risk disease. More studies in larger groups are needed to assess this further.”
Enrollment for the trial also highlighted that black men exhibited a response rate to the screening invitation that was merely one-fifth that of white men. The authors emphasize that addressing this discrepancy will be imperative for future research endeavors.
Saran Green, a study author associated with King’s College London, points out that one out of four black men will develop prostate cancer over their lifetime, a figure twice as high as that for men from other ethnic backgrounds. Given this heightened risk and the concerning finding that black men were five times less likely than white men to participate in the REIMAGINE trial, it becomes crucial to incorporate strategies within any prospective national screening program that effectively engage black men and encourage their participation in testing.
