Experts are optimistic about a simple blood test that detects cancer even before a tumor develops. American scientists called it the "holy grail" of cancer research.
The blood test, called liquid biopsy, can identify the genetic traces of cancers by detecting even the tiniest pieces of DNA released by cancer cells into the bloodstream. A trial of the method showed that it can identify 10 different types of cancers.
Researchers from the United States presented their findings at the 2018 conference of the American Society of Clinical Oncologists in Chicago.
Experts from the United Kingdom embraced the result of the study and hoped that liquid biopsy could become a part of a "universal screening" method accessible to cancer patients worldwide.
Liquid Biopsy
A liquid biopsy involves conducting gene sequencing similar to the genetic reading that people used to track down their genealogy. The method consists of three steps: testing the genome for DNA composition, detecting possible gene mutation, and finally, identifying a specific change in DNA that shows that cancer has already affected the cells.
For the research presented at the conference, the American team, led by Dr. Eric Klein from the Cleveland Center in Ohio, examined the medical records of more than 1,600 people. Out of the records, 749 people stated that they were cancer-free, even without a prior medical diagnosis. Meanwhile, 878 of them stated that they were newly diagnosed with a certain type of disease.
The liquid biopsy was able to detect pancreatic, ovarian, liver, and gallbladder cancers with the highest accuracy. The method detected the diseases in at least four out of five patients.
On the other hand, the liquid biopsy was less accurate in detecting cancer in the breast, stomach, uterine, and early stage of prostate cancer. It also showed slightly less accuracy in distinguishing lymphoma, myeloma, bowel cancer, as well as head and neck cancer.
Nevertheless, Klein and his team are positive that with further scientific development, the liquid biopsy will serve its purpose in the future.
"This is potentially the holy grail of cancer research, to find cancers that are currently hard to cure at an earlier stage when they are easier to cure, and we hope this test could save many lives," Klein said.
"Most cancers are detected at a late stage, but this liquid biopsy gives us the opportunity to find them months or years before someone would develop symptoms and be diagnosed."
Health experts in the United Kingdom were equally positive. Simon Stevens, chief executive of the National Health Service England, describes the method as a "breakthrough."
Nicholas Turner, a professor from the Institute of Cancer Research in London, and Fiona Osgun from Cancer Research UK both described it as "exciting."
Liquid Biopsy Using Electronic Chips
Meanwhile, the University of California San Diego announced that it already conducted a trial of a liquid biopsy method that involved an electronic chip-based system to detect pancreatic cancer. The result of their trial, published in ACS Nano, showed that the system can extract exosomes directly from blood in a matter of minutes.
Jean Lewis, the first author of the study and an assistant project scientist in the Department of Nanoengineering at the university, said that the method required no extra processing.
The electronic chip-based liquid biopsy only involved applying a drop of blood, turning the system on, waiting several minutes, adding fluorescent labels, and looking under the microscope for the result. Bright fluorescent circles will appear in the blood sample if positive for pancreatic cancer.
