Researchers from Stanford University have developed a new diagnostic tool that can detect genetic mutations in small amounts of tumor-derived DNA circulating in a patient’s blood sample.
The single color digital PCR assay needs a fraction of a tube of blood and can successfully detect three mutation-bearing molecules in a single reaction, according to the report published in The Journal of Molecular Diagnostics.
“For monitoring patient tumors, only a handful of blood tests are available which are limited to only several types of cancers,” lead investigator Dr. Hanlee Ji said in prepared remarks. “Nearly all cancer patients require monitoring by whole body imaging, which can be costly, complex, and time-consuming. In contrast, molecular tests like the one we have developed will enable patients to be monitored at every visit, and thus have the potential for quickly tracking cancer growth and spread. Moreover, the test’s rapid turnaround and relatively low cost, especially compared to next-generation DNA sequencing, provide a potential opportunity for universal monitoring of more patients than is currently done.”
The team of Stanford researchers used the test to assess samples from six patients – five colorectal cancer patients and one patient with cholangiocarcinoma.
The scientists reported that they were able to detect tumor-derived circulating DNA in three patients and, in one patient, the test was able to identify the presence of three different mutations.
The three patients whose samples did not show elevated levels of tumor-derived DNA were actively undergoing treatment at the time of collection, the researchers noted.
The single-color digital PCR assay offers a competitive edge over other tools for analysis of ciculating tumor DNA, the team reported, because the test doesn’t rely on pre-amplification, which can introduce errors.
“This test is simple enough to set up and analyze without extensive training, and therefore, it can be implemented by anyone, making it highly accessible to any laboratory,” lead author Christina Wood Bouwens said. “It has been truly motivating to work with a technology that will help transform the way that we monitor and treat individuals with cancer. I am excited to share our findings with the cancer research community.”