New Blood Test For Cancer Monitoring

There is a new type of test that can detect genetic mutations in minute amounts of DNA that is released from cancer cells into the blood, according to Stanford University scientists.  The test is called single color digital PCR and requires just a fraction of a tube of blood that can detect as few as three mutation-bearing molecules in a single reaction.  The report in The Journal of Molecular Diagnostics reports that this highly sensitive test has the potential to be personalized to recognize mutations unique to any individual cancer.

There are now only a handful of blood tests available that are limited to only several types of cancers for monitoring patient tumors.  The patients require monitoring by whole body imaging that can be costly, complex and time-consuming.  Molecular tests like the new one developed will enable patients to be monitored at every visit and have the potential for quickly tracking cancer growth and spread.  The rapid test turnaround and fairly low cost  (especially compared to next-generation DNA sequencing) will provide a potential opportunity for universal monitoring of more patients than is currently done, according to lead investigator Hanlee P. Ji, MD, Associate Professor in the Department of Medicine at Stanford University and Senior Associate Director of the Stanford Genome Technology Center.

Based on the tests of samples from six patients, the researchers were able to identify tumor-derived circulating DNA from three out of six patients.  The assay was able to show the presence of 3 different mutations in one patient.  Samples of 3 patients whose samples did not show elevated cancer DNA were undergoing active treatment at the time of collection.

This single-color digital PCR test offers several advantages over other methods of circulating tumor DNA analysis.  The main advantage is the new technique does not rely on pre-amplification that can introduce errors and biases.

It doesn’t take extensive training and is simple enough to set up and analyze to be implemented by anyone, making it highly accessible to any laboratory.  The lead author and researcher is Christina Wood Bouwens of the Stanford Genome Technology Center and the Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, California.

Dr Fredda Branyon