Fighting Cancer with the “Liquid Biopsy”
A researcher in China has made a major breakthrough in detecting liver cancer in its earliest stages using DNA sequencing technology. Dr. Dennis Lo of the Chinese University of Hong Kong asserts that it is possible to detect certain kinds of cancers early on using a blood test. This is made possible by the fact that dying cancer cells shed DNA into the blood so that when contrasted with the patient’s genome, doctors can identify early signs that cancer is developing in a patient’s bloodstream.
Dr. Lo is famous for his previous research in 1997 that showed that fetuses shed bits of their DNA into their mothers’ bloodstreams. This discovery of cell-free fetal DNA (cffDNA) allows for simple and early screening, via a standard blood draw, for genetic conditions like Down syndrome in utero instead of substantially more invasive methods.
Dr. Lo is now applying a similar analysis to cancer screenings in China—where there is a particular prevalence of liver cancer—to determine if the cancer can be detected and treated early enough to prevent its deadly progression. The method, called a “liquid biopsy,” has already shown impressive results in a Chinese study identifying early stages of liver cancer in 13 patients that are now surviving with the disease, with a typical survival rate of less than 70 percent. Due to the success of the early trials, professor of genomics at the Scripps Research Institute (TSRI) Eric Topol called the method the “stethoscope for the next 200 years.” Arguably, this method which will not only help identify cancers early on, but could also potentially help patients already fighting the disease by identifying the genetic mechanisms that are driving the disease forward. [1]
Currently, Dr. Lo is in a technology race against similar research from Johns Hopkins University that is also working to detect cancer through a blood test. Both technologies benefit from rapid advancements in DNA sequencing. Soon DNA sequencers could even be the size of a cell phone, which would make tests for early stage cancers more accessible to patients in remote locations.
While the test is currently expensive, Dr. Lo is hopeful that, similar to the Down syndrome screening test, as the method is applied by more doctors, the price of carrying out a “liquid biopsy” will decrease giving even remote and poor patients the ability to detect other devastating chronic diseases like diabetes, heart disease and stroke at earlier stages, with positive effects for the future of human health.
[1] https://www.technologyreview.com/s/534991/liquid-biopsy/
