New blood test for early cancer detection

Researchers, led by an Indian-origin scientist, have developed a new blood test that may detect a broad range of cancers in the earliest stages by forcing tumours to create a unique protein.
Stanford University Medical School researchers injected DNA microcircles, a customised genetic construct consisting of tiny rings of DNA, into mice.
They used a blood test to show that mice with tumours produced a substance that tumour-free mice did not.
With blood and urine tests, doctors must depend on detecting biomarkers that the tumour itself makes, 'FoxNews.Com' reported.
"The challenge for those kinds of biomarkers is that they're rarely very specific and often not made in sufficient quantities," Sanjiv "Sam" Gambhir, professor and chair of radiology and director of the Canary Centre at Stanford for Cancer Early Detection, said.

On the other hand, DNA minicircles work by forcing tumours to make a protein that it otherwise would not to detect the presence of cancer.

"We flip the problem around. (You're) no longer dependent on nature to make a molecule that's unique to cancer. You're given a pill that forces cancer cells to make the molecule for you," said Gambhir, the study's senior author.
For the purposes of their animal trial, Gambhir noted that a cancerous tumour one cubic millimetre in size, equal to about a grain of rice, would be detectable.
While researchers have yet to conduct trials with human participants, Gambhir said he hopes minicircles will be able to help detect early and stage 1 cancer.

The DNA minicircles, which are comprised of tiny rings of DNA, work by going into a cancer cell and turning on the cell's machinery to make RNA.
The RNA then makes protein, which in this case is secreted embryonic alkaline phosphatase (SEAP), which then serves as a cancer biomarker.