A team of Northwestern University researchers lead by C. Shad Thaxton, Ph.D., M.D, and Chad Mirkin, Ph.D., has detected previously undetectable levels of prostate-specific antigen (PSA) in patients who have undergone radical prostatectomy using an extremely sensitive nanotechnology-based tool known as the biobarcode system.
This new test is 300 times more sensitive than commercially available PSA tests.
The 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.
It may also give assurance to some men who have been treated that their disease will not return.
“This new PSA test may alter the management of patients who have been treated with surgery for prostate cancer,” Dr. Catalona said.
Prostate cancer specimens from his patients were used in this nanotechnology research, and Dr. Catalona and his research collaborators continue studying possible practical applications for these new findings.
After the removal of the prostate gland, patients typically have PSA levels that are undetectable when measured using conventional diagnostic tools. Presently, physicians wait for a rising PSA to initiate treatments for recurrence.
Studies show that postoperative radiation therapy, called adjuvant radiation, given early to patients with adverse pathology findings reduces the recurrence rate and improves survival.
“Because the “nano test’ is more sensitive than the current commercially available PSA tests, it may allow physicians to target adjuvant radiation for patients destined to have a life-threatening tumor recurrence,” Catalona said.
In addition, monitoring a patient’s PSA levels could assess the effectiveness of post-operative treatment.
As well as targeting men much earlier for life-saving treatments against recurrence, this test could assure patients with nanotechnology detectable PSA information that their cancer will not recur much sooner than with conventional diagnostic tools.
Tracking PSA levels early, before conventional tools are able, may allow doctors to validate treatments for recurrent cancer such as radiation, hormone therapies and chemotherapies. The most effective therapy will keep the PSA levels down.
“We have defined a new zero for PSA,” Mirkin said. He is the principal investigator of the Northwestern CCNE (Nanomaterials for Cancer Diagnostics and Therapeutics Center for Cancer Nanotechnology Excellence).
The Northwestern team, led by Drs. Thaxton and Mirkin, is now conducting a retrospective study of 260 patients (Catalona) and plans to do a large study in the near future.