• Posted March 1, 2024

PSA Test Might Overdiagnose Prostate Cancers in Black Men

A new British study suggests that the prostate-specific antigen (PSA) test, long used to spot prostate cancers, might lead to overdiagnosis in Black men.

Researchers now theorize that Black men may have naturally higher levels of the antigen in their blood than white men, but that it does not indicate any higher risk for prostate cancer.

If Black patients are being overdiagnosed, that could mean that many receive unnecessary follow-up MRIs and onerous prostate biopsies.

"Overdiagnosis of cancer may not sound as worrying as under-diagnosis, but we need to redress the balance in the evidence base to get more precise and accurate prostate cancer diagnosis to avoid unnecessary biopsies which can lead to psychological distress and sepsis," explained study lead author Dr. Tanimola Martins, a senior research fellow and lecturer at the University of Exeter.

"We need more research to ensure everyone gets the best diagnosis, regardless of their ethnicity," Martins said in a university news release.

The PSA test was once routinely used by doctors to help diagnose cancers.

However, over time the screen came under fire, because it too often spotted "indolent" tumors that were slow-growing and might be better left untreated.

Currently, the American Cancer Society leaves the decision to have a PSA test up to an informed discussion between a patient and his doctor.

In the new study, Martin's team examined the medical records of over 730,000 British men, ages 40 or older. The researchers tracked which of the men were diagnosed with prostate cancer after receiving a test result showing raised levels of PSA.

More than 80 percent of the men had normal PSA levels, the team noted.

However, among men with raised levels of PSA, Black men typically had higher levels than either white or Asian men, the researchers found.

Furthermore, among those men with a raised PSA, Black men were more likely to receive a prostate cancer diagnosis compared to white or Asian men.

However, when Martin and his colleagues focused solely on those men who went on to be diagnosed with advanced forms of prostate cancer, PSA levels were found to be similar between Black and white patients.

That suggests that Black men may present with higher PSA levels than white men on tests, but actually face no higher risk of a dangerous prostate cancer, the researchers reasoned.

Black men's naturally higher PSA levels may be leaving them vulnerable to overdiagnosis, Martin's group believes.

The study was published Feb. 29 in the journal BMC Medicine.

According to Naser Turabi, director of evidence and implementation at Cancer Research UK, there's long been doubt regarding the usefulness of the PSA for men in the absence of prostate cancer symptoms.

That may be doubly true for Black men, he added.

"Overall, research shows that using the PSA test in men with no prostate symptoms does not reduce the number of prostate cancer deaths," Turabi said. "This study highlights that the test may be causing harm to Black men in particular. This may be because they have naturally higher levels of the protein PSA, making the test even less accurate at finding prostate cancers that need to be treated."

Turabi believes a better, more accurate diagnostic test prostate cancer is needed.

"The PSA test is not suitable for men who do not have symptoms of prostate cancer, and more research is needed to find an effective and accurate test that saves lives from the disease and reduces unnecessary treatment," he said.

More information

Fid out more about the PSA test at the National Cancer Institute.

SOURCE: University of Exeter, news release, Feb. 29, 2024