IsoPSA Test Superior to PSA in Prostate Cancer Detection

The new IsoPSA blood test is superior at detecting prostate cancer than current tests, according to a study published in European Urology.

More specifically, IsoPSA more precisely distinguishes cancer from benign conditions and identifies patients with high-risk of disease.

Once the IsoPSA is validated, its use may significantly reduce the need for biopsies, in addition to lowering the risk of overdetection and overtreatment of nonlethal prostate cancer.

Included in the study were 261 men scheduled for a prostate biopsy at 5 academic and community centers in the United States enrolled between August 2015 and December 2016.

“Despite criticism, PSA has transformed the landscape of early detection, screening, and management of prostate cancer in the last few decades,” said lead investigator Eric Klein, MD. “Unfortunately, PSA is tissue-specific but not cancer-specific, leading to overdiagnosis and overtreatment of biologically insignificant cancers, which is widely recognized as a key limitation in its clinical utility.”

For the study, investigators directly compared the clinical performance of the IsoPSA test to PSA itself with patients already scheduled for prostate biopsy.

The results of the study showed that IsoPSA was significantly superior to PSA in discriminating between prostate cancer and benign conditions, and identifying patients with high-grade disease.

The first indication may bolster the use of IsoPSA for screening by primary care physicians, while the second indication may be helpful for urologists in identifying patients who would benefit most from curative intent therapy and other options.

“The methodology used in the IsoPSA assay represents a significant departure from conventional ways to define biomarkers in blood, and may be applicable to improving other cancer biomarkers,” Dr Klein said.

If the IsoPSA test is validated and adopted clinically, it could significantly reduce the rate of unnecessary biopsies by nearly 50%.

“Due to its inherent simplicity, requiring only a blood draw and presenting information to the physician in familiar context using a single number—–just like PSA itself––we are quite hopeful in IsoPSA’s future utility after further validation studies,” said co-author Mark Stovsky, MD.