That knowledge could be invaluable, the researchers believe. "If the treatment is not working, we can try a different approach," Thaxton said.
The journal report describes use of the nanotest for 18 men who had prostate cancer surgery. A larger study, with 260 participants, is also under way at Northwestern. "We hope to have data by the end of the year," Mirkin said.
Even larger studies that are necessary to validate the assay could start "within a year or two," Thaxton said.
Both Mirkin and Thaxton are stockholders in Nanosphere, Inc., the company that has licensed the nanotechnology from Northwestern and is applying it to a wide variety of medical tests.
"They have six FDA approvals already," Mirkin said of the company's medical nanotechnology tests. Approval by the U.S. Food and Drug Administration is required for a test to be used in medical practice in the United States.
For now, caution is needed until widespread studies are done, said Dr. Durado Brooks, director of prostate and colorectal cancers at the American Cancer Society.
"We're talking about only 18 patients, but more importantly, we still don't know if this is clinically significant," Brooks said. "If we find a recurrence earlier, does it make a difference if we treat it earlier? We don't know if it will make a difference long-term."
While he called the work "exciting," Brooks said "it is way too early in the game to tell whether it will have clinical significance."
For more on PSA testing, see the U.S. National Institutes of Health.
SOURCES: Chad A. Mirkin, Ph.D, professor, chemistry, Northwestern University, Chicago; C. Sha
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