Stanford University scientists have developed a new type of low-cost blood test that has the potential for quickly tracking cancer growth and spread.The test requires only a fraction of a tube of blood and can detect genetic mutations in minute amounts of DNA released from cancer cells into the blood, according to a study published in the The Journal of Molecular Diagnostics."For monitoring patient tumours, only a handful of blood tests are available which are limited to only several types of cancers. Nearly all cancer patients require monitoring by whole body imaging, which can be costly, complex, and time-consuming," said lead investigator Hanlee P. Ji, Associate Professor at Stanford University in the US."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," Ji added.The test, which is called single colour digital PCR, can detect as few as three mutation-bearing molecules in a single reaction, the study said.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," Ji said."This test is simple enough to set up and analyze without extensive training, and therefore, it can be implemented by anyone," noted lead author Christina Wood Bouwens of the Stanford Genome Technology Center.