A new blood test named Stockholm3 has demonstrated greater accuracy in detecting aggressive prostate cancer compared to the traditional prostate-specific antigen (PSA) test, according to a recent study.
In a clinical trial involving over 12,000 men aged 50 to 74, primarily from Sweden and Europe, the Stockholm3 test identified 90% of aggressive prostate cancer cases. This contrasts with the PSA test, which detected 74% of such cases during the same study period. Researchers from the Karolinska Institutet in Sweden published the findings in the Annals of Internal Medicine.
Prostate cancer screening aims to identify dangerous cases early while minimizing unnecessary follow-ups for non-aggressive disease. The Stockholm3 test was found to miss significantly fewer serious cancer cases than the PSA test. The number of men incorrectly classified as high-risk was similar between both tests.
"Our results show that Stockholm3 identifies significantly more aggressive cancer cases than PSA, without increasing the number of unnecessary follow-ups," stated Thorgerdur Palsdottir, a researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet. She added that these findings suggest a potential shift in prostate cancer screening practices, enabling earlier detection of aggressive disease and reducing unnecessary examinations.
Hari Vigneswaran, MD, chief medical officer of A3P Biomedical, the maker of Stockholm3, described the findings as "promising." He noted that despite its widespread use since the 1990s, the PSA test has limitations, including leading to invasive follow-up testing, contributing to over-diagnosis of non-aggressive cancers, and missing a substantial amount of aggressive disease.
Early detection of aggressive prostate cancer when it is still confined to the prostate is crucial, as the five-year survival rate is nearly 100% in such cases. Data from the National Cancer Institute's SEER database indicate a rise in metastatic prostate cancer over the past decade, suggesting a need for improved early detection methods for aggressive, curable forms of the disease.
Stockholm3 aims to reduce the need for unnecessary MRIs and biopsies. However, the test is currently investigational and not yet available in the U.S. The company plans to seek FDA approval for routine screening and is working to generate the necessary evidence, including U.S.-based data, to support this pathway. While Stockholm3 estimates a man's risk of aggressive prostate cancer, a biopsy remains the definitive method for diagnosis.