"New Zero" for PSA Defined

A team of Northwestern University researchers, using an extremely sensitive tool based on nanotechnology, has detected previously undetectable levels of prostate-specific antigen (PSA) in patients who have undergone radical prostatectomy.

The researchers found measureable PSA levels in each post-operative patient in its study, thanks to the power of the nanoparticle-based bio-barcode assay developed at Northwestern. The technology is 300 times more sensitive than commercially available PSA tests. After the removal of the prostate gland, patients typically have PSA levels that are undetectable when measured using conventional diagnostic tools.

This ability to easily and quickly detect very low levels of PSA may enable doctors to diagnose men with prostate cancer recurrence years earlier than is currently possible. Prostate cancer is the second leading cause of cancer death for men in the United States. (Only lung cancer is more deadly.)

'We have defined a new zero for PSA,' said Chad A. Mirkin, George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, professor of medicine and professor of materials science and engineering. 'This level of sensitivity in detecting low concentrations of PSA will take the blinders off the medical community, especially when it comes to tracking residual disease.'