Bypassing biopsies

Nanostics Inc. is analyzing biomarkers on tumor-derived vesicles in blood to increase the accuracy of routine prostate cancer screening, and provide a readout of a tumor's aggressiveness. When used with routine PSA screening, the company’s EV-FPS assay could avoid biopsies in men who do not have aggressive cancers.

The prostate-specific antigen (PSA; KLK3) blood test has a sensitivity of only about 20% to detect prostate cancer, which means it misses 80% of potential cases, according to results from the Prostate Cancer Prevention Trial. Its specificity to detect any prostate abnormality is 90%, but drops to 20% when it comes to identifying high-risk prostate cancer. Thus only 20% of men who undergo a confirmatory biopsy actually have aggressive cancer that requires treatment. ...