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New research finds many people only need a test once every 5 years. MoMo Productions/Getty Images
  • Novel research could change, and hopefully simplify recommendations and guidelines about a common prostate cancer screening tool.
  • The widely used prostate-specific antigen (PSA) test is a simple but contentious test that has been the focus of an intense debate.
  • While the PSA test has been shown to reduce prostate cancer mortality there are also harms of the test.

In new research this month, scientists across the United States and Europe are signaling that it is time to reevaluate prostate cancer screening — and a simpler approach could be the best approach.

The focus of numerous studies this month is prostate-specific antigen (PSA) testing, which has been a standard prostate cancer screening tool for decades. The test is a relatively non-invasive, simple blood test, which can be performed at a doctor’s office. However, the test is also controversial, leading to a significant rate of false positives, overtreatment, and other harms.

Current prostate cancer screening recommendations and benefits are not nearly as clear-cut as with other forms of cancer.

Experts believe that with new tools and data, there should be clearer guidance on the continued role of PSA testing in prostate cancer screening that will simultaneously drive down prostate cancer mortality while minimizing additional harms from the test.

New research presented at the European Association of Urology Congress in Paris this month, indicates that for low-risk men, a blood test once every five years is sufficient. The study will be published later this month in the journal European Urology.

Researchers released their findings from the PROBASE trial in order to better define categories of prostate cancer risk in mid-life, and how screening guidelines should apply to them.

The PROBASE trial involved about 12,500 men between the ages of 45-50 to test different screening procedures for prostate cancer. Men were categorized into low, intermediate, and high-risk categories after a baseline PSA test.

The PSA test measures prostate-specific antigen in the blood, a potential indicator of cancer. Those with higher scores were considered at greater risk. A PSA level of under 1.5 ng/ml was considered low risk,1.5-3ng/ml intermediate, and a PSA of 3 ng/ml or higher was categorized as high risk.

Researchers instructed low-risk men to have an additional PSA test done 5 years onward. Medium-risk men were told to get the test in 2 years. Those with high risk received additional treatment, including an MRI scan and prostate biopsy.

Almost none of the men in the low-risk group were subsequently diagnosed with cancer at the 5-year mark, indicating that one every 5 years is sufficient. Furthermore, they found that by increasing the low-risk threshold of the PSA test from 1.0 ng/ml to 1.5 ng/ml, they would also significantly cut down the number of people needing to seek additional screening.

“This enlarges the group with very low risk by 20% to nearly 90% at age 45. And they only need to repeat the PSA test 5 years later. Further follow-up aims to show that 10 yearly re-testing may be possible in these 90% of middle aged men. This would tremendously improve the harms of screening by increasing the negative predictive value of PSA,” Peter Albers, MD, a Professor of Urology at the German Cancer Research Center, and one of the authors of the research, told Healthline.

Two new studies in JAMA also looked at the effectiveness of PSA testing, and how it could potentially be used in concert with other screening tools to improve its accuracy.

In the first article, British researchers found that while PSA testing did improve prostate cancer mortality on the whole, the effect was limited. The study included more than 400,000 men who had not been diagnosed with prostate cancer. Participants were randomly assigned to two groups: one was invited to receive a PSA test, while the other group didn’t receive the screening.

In total, the group that received the PSA screen experienced less than one-tenth of a percent (0.09%) reduction in prostate cancer mortality after an average follow-up of 15 years.

“Only a few less men who were invited for a PSA test died because of prostate cancer. There wasn’t much difference between the two groups,” Richard Martin, PhD, a Professor Clinical Epidemiology at University of Bristol, and lead author of the study, told Healthline.

“There is an urgent need to find ways of detecting cancers that need treating early and to avoid the diagnosis of low risk cancers,” he added.

Another study in JAMA, published the same day, suggests that the use of a biomarker panel in addition to PSA testing, could offer greater benefits in terms of screening while reducing unnecessary treatment.

More than 60,000 men took part in the Finnish study. Similar to the British research, men were assigned either to an experiment group receiving a PSA test, or a control group that did not. Men who had a PSA level of 3.0 ng/ml or higher were asked to undergo an additional biomarker test known as a 4-kallikrein panel blood test, which screens for high-risk prostate cancer. If they scored high enough on the panel, they would then continue on towards additional treatment, including an MRI, and if necessary, a biopsy.

In an accompanying editorial on the research, Jeffrey Tosoian, MD, MPH, an Assistant Professor of Urology and Director of Translational Cancer Research at at Vanderbilt University Medical Center, writes, “the current trial informs a more contemporary, pragmatic approach to screening, with appropriate use of biomarkers and imaging to optimize patient selection for biopsy.”

This suggests that additional tools are ensuring that men with higher risk are getting additional treatment, while those with lower risk are not being subjected to unnecessary biopsies.

“All the data coming out are telling us that, with the tools available today, we very much can, and are, reducing the, the harms that came along with PSA testing in a prior era really significantly, while still preserving the benefit in diagnosing the higher grade cancers that need to be detected and treated at an early stage,” Tosoian told Healthline.

Prostate cancer is the second most common cancer in men after skin cancer. About one-in-eight men will be diagnosed with prostate cancer during their lifetime. In 2024 in the United States, there will be an estimated 300,000 new cases of prostate cancer per year, with about 35,000 deaths attributed to it.

Globally, there are roughly 1.4 million new cases per year, but that number is expected to more than double to 2.9 million cases in 2040, according to The Lancet Commission on Prostate Cancerreport published this month.

Unlike other forms of cancer, prostate cancer is typically slow-growing, so much so that a low-grade form of it may require no treatment during a man’s lifetime.

Due to the risk of false positives and overdiagnosis, screening for prostate cancer, as well as specific guidelines about how and when it should be undertaken, is a complex issue. The American Cancer Society and the US Preventive Services Task Force both recommend speaking with a doctor and making an informed decision about screening.

Prostate cancer screening is a complex issue that men should discuss with their doctor to weigh the risks and benefits.

New research is helping to better inform patients and doctors about when it is appropriate to seek out PSA testing and subsequent screening, such as MRI and biopsy.

For low-risk men, a PSA test once every 5 years may be sufficient.

Additional measures, such as biomarker tests may help to improve the accuracy of prostate cancer screening and improve recommendations about additional treatment.