Researchers in Australia said this week they have discovered a potential new way of testing for cancer that takes less than 10 minutes. The story is getting lots of press. But when examined more carefully the new test may not be as exciting as it sounds. The overall picture is that this test will not be usable by people to diagnose or detect cancer in the human body for many, many years, but being able to harness a universal marker of cancerous DNA is promising.
The study from of the University of Queensland examined 72 tissue samples for how the DNA of cancer reacted differently than regular healthy human DNA in water, and how this could be used in a blood test to diagnose the presence of cancer. To do this, the researchers used microscopic particles that can detect the DNA signature of cancer and change color when it was present in water.
The results showed that this method of testing had a 90% success rate when used on cancer cells—but it did not show that it would be successful in humans. And there were limitations. The study said this method of detection, “in its current form is only able to determine the presence of disease and a detailed analysis is required to fully understand the type, stage and disease recurrence.”
So, this is a long way for use as diagnostic test. “While the preclinical studies sound exciting, it will be important to see how this works in humans,” says Dr. Heather Yeo, Assistant Professor of Surgery and Healthcare Policy and Research, New York Presbyterian—Cornell Medicine.
The researchers agree that there are still many questions to be answered. “We were very excited about an easy way of catching these circulating free cancer DNA signatures in blood,” one of the researchers at the university, Professor Matt Trau, explained. “We certainly don’t know yet whether it’s the holy grail for all cancer diagnostics, but it looks really interesting as an incredibly simple universal marker of cancer, and as an accessible and inexpensive technology that doesn’t require complicated lab-based equipment like DNA sequencing.”
Further, it’s important to note that this method of DNA detection was only tested with cells of certain types of cancer including breast, colorectal, prostate and lymphoma. More information is also needed about the sensitivity and specificity of the test in order to understand how applicable it will be. “Those two things help us understand how useful screening tests are,” Dr. Yeo explains. “If they are sensitive, but not specific they may have false positives, which can lead to unnecessary testing and worry. If it it specific but not that sensitive it may miss cancers.”
We will continue to track updates as more studies are done in years to come.