By Ann Miller Baker
Cancer researchers call it the holy grail — a long-sought test that could quickly detect the presence of any of a variety of cancers. Investigators at The University of Queensland in Australia think they may have found it. They discovered that DNA fragments from cancer cells adopt a unique structure in solution, one that clings to tiny particles of gold. Their study, published in Nature Communications, detailed how they made their discovery and demonstrated its validity using 200 blood and biopsy tissue samples. Their simple test was correct up to 90 percent of the time.
Molecular pathologist Dr. Theresa Boyle says blood testing is routinely performed at Moffitt Cancer Center to detect genetic mutations that may help physicians choose targeted therapies based on the genetic sequences they find. Such sequencing and analysis can be costly and take days, if not weeks.
“But this new technology is novel and unique,” said Boyle. “It’s a 10-minute test where there’s a change in the solution’s color when cancer DNA is present in the blood. This change in color doesn’t happen when there’s only normal DNA in the blood.”
In a University of Queensland press release, study co-author Dr. Abu Sina said the color change is linked to a basic difference between normal and cancer DNA. “The levels and patterns of tiny molecules called methyl groups that decorate DNA are altered dramatically by cancer,” said Sina. “These methyl groups are key for cells to control which genes are turned on and off. In healthy cells, they are spread out across the genome, but the genomes of cancer cells are essentially barren except for intense clusters of methyl groups at very specific locations.” Sina said the Queensland team found this signature pattern “in every type of breast cancer we examined, and in other forms of cancer including prostate, colorectal and lymphoma.”
While the experimental test could tell if cancer is present, it does not indicate the type, location or stage of that cancer. Further diagnostics would be required to determine that information before treatment.
Boyle lauds any advance in cancer diagnostics, but says further human studies will be needed before the experimental test makes its way into everyday use. “I think there’s great promise with the test, but it’s not ready for prime time today with clinical care.”
Should it prove effective and accurate, Boyle says the 10-minute test could be a boon to patients who require frequent testing to monitor for recurrence after a cancerous tumor has been removed. It could also become a simple and quick cancer screening tool in the future.