Nanoparticle PSA test predicts prostate Ca recurrence

An ultrasensitive PSA test using nanoparticle-based technology may be able to definitively predict whether the cancer is cured long term or if it will recur, new research from Northwestern University’s Feinberg School of Medicine and the University International Institute for Nanotechnology, Chicago shows.

"These studies suggest that the nanotechnology PSA test might become the preferred postoperative PSA test for men who have been treated with radical prostatectomy," said senior author William Catalona, MD, of the Feinberg School of Medicine. "It should be especially useful in the early identification of men who would benefit from adjuvant postoperative radiation therapy and those who need postoperative salvage radiation therapy for recurrence."

In the study, which was presented at the AUA annual meeting in San Francisco, researchers obtained blood serum retrospectively from men whose PSA serum samples had been frozen after surgery and whose assays showed an undetectable PSA level based on the conventional test. Northwestern researchers then tested those serum samples using VeriSens PSA (Nanosphere, Inc., Northbrook, IL [used in research only]), the more sensitive nanotechnology-based test.Using the new test, researchers found that the low and non-rising PSA levels meant that the patients’ prostate cancer was effectively cured and did not return over a period of at least 10 years. They also found that a PSA level higher than that expected from the periurethral glands based on the new test meant the patients would have their disease recur.

Co-author C. Shad Thaxton, MD, PhD, said the next step is a prospective clinical trial to compare the nanoparticle-enhanced PSA assay to traditional PSA assays and determine if earlier detection and treatment can save lives.

Dr. Thaxton and co-author Chad A. Mirkin, MD, are shareholders in Nanosphere Inc., and Dr. Catalona is a consultant/adviser and investigator for the company.