Stockholm3 Blood Test Detects 90% of Aggressive Prostate Cancers, Outperforming Standard PSA Screening
Key Insights
In a study of over 12,000 men, the Stockholm3 (search) blood test identified 90% of aggressive prostate cancer (search) cases compared to 74% for the standard PSA test.
Stockholm3 (search) missed significantly fewer aggressive cancers than PSA without increasing the number of unnecessary follow-ups or false positives.
Early detection is critical as the five-year survival rate for prostate cancer (search) confined to the prostate is nearly 100%.
A new blood test called Stockholm3 (search) has demonstrated the ability to detect 90% of aggressive prostate cancer (search) cases, significantly outperforming the traditional prostate-specific antigen (search) (PSA) test, according to a study published in the Annals of Internal Medicine. Researchers from the Karolinska Institutet in Sweden evaluated the test in more than 12,000 men aged 50 to 74, most of whom were Swedish or European, and followed participants for two years.
During the follow-up period, 443 men were diagnosed with aggressive prostate cancer (search). Stockholm3 (search) identified 90% of these cases, compared to just 74% detected by PSA testing. Importantly, Stockholm3 missed "significantly fewer" serious cancer cases than PSA, while the number of men incorrectly classified as high-risk was similar across both tests.
A Persistent Challenge in Prostate Cancer (search) Screening
Thorgerdur Palsdottir, a researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet, highlighted the core challenge in prostate cancer (search) detection. "One of the major challenges in prostate cancer is being able to identify the cases that are truly dangerous," she said in a statement.
"Our results show that Stockholm3 (search) identifies significantly more aggressive cancer cases than PSA, without increasing the number of unnecessary follow-ups," Palsdottir added. "These results point toward a potential change in how prostate cancer (search) screening can be conducted. A more precise blood test could enable earlier detection of aggressive disease while reducing the number of unnecessary follow-up examinations and procedures."
PSA's Well-Documented Limitations
Hari Vigneswaran, MD, chief medical officer of Stockholm3 (search)-maker A3P Biomedical (search) and study co-author, confirmed that PSA has been the standard for prostate cancer (search) screening since the 1990s despite its shortcomings. "It leads to invasive and costly follow-up testing, contributes to over-diagnosis of non-aggressive cancers and, most importantly, it misses a substantial share of aggressive disease," Vigneswaran said.
The clinical stakes are high. When aggressive prostate cancer (search) is found while still confined to the prostate, the five-year survival rate is close to 100%, underscoring the importance of early detection. Data from the National Cancer Institute's SEER database indicate that metastatic prostate cancer cases have risen over the past decade, suggesting that "we have not improved early detection of the aggressive, curable disease that screening is meant to catch," Vigneswaran noted.
"The goal of screening is to find the cancers that need treatment while they are still curable, without raising the number of men who screen positive but don't have aggressive disease," he said.
Reducing Unnecessary Procedures
Beyond improved detection, Stockholm3 (search) could reduce the need for unnecessary MRIs and biopsies, according to the researchers. This dual benefit—catching more aggressive cancers while avoiding unnecessary invasive procedures—represents a meaningful advance in prostate cancer (search) screening.
Limitations and Regulatory Path Forward
The study has notable limitations. Stockholm3 (search) is an investigational device and is not currently available for sale in the United States. While the blood test estimates a man's risk of aggressive prostate cancer (search), a biopsy remains the gold standard for confirming the disease.
A3P Biomedical (search) plans to seek FDA approval to use the test for routine screening and will "generate the evidence needed to support that pathway, including U.S. data," Vigneswaran said.