Researchers claim they have developed a 99% accurate blood test to detect 12 different types of cancer

Earlier this year GRAIL inc., a biotechnology company in California, US, announced that their researchers have developed a blood test to detect 12 different types of cancer in the early stages. The company also claimed that the test is 99% accurate — with just 1% chance of false-positive — and a 94% chance of finding out the tissue of origin of cancer. Now, the Dana-Farber Cancer Institute, a teaching affiliate of the Harvard Medical School, has corroborated these findings, saying that the blood test devised by GRAIL may actually give a correct diagnosis for cancer in 99.4% cases. [caption id=“attachment_7335521” align=“alignleft” width=“380”]  Representational image.
Image by PDPics from Pixabay[/caption] Globally, one in six deaths occurs due to cancer. Scientists all over the world have been looking for easier and quick detection techniques that can help them stop disease progression at an early stage. The GRAIL research may a significant stepping stone on this path. The four-part research was published in the  Journal of Clinical Oncology, a peer-reviewed medical journal by the American Society of Clinical Oncology. The cancer types it looked for included anorectal, colorectal, oesophagal, gastric, head and neck, hormone receptor-negative breast, liver, lung, ovarian, and pancreatic cancers, and multiple myeloma and lymphoid neoplasms.

The research

Scientists at GRAIL inc. focused on something known as circulating tumour DNA (ctDNA) and methylation markers. ctDNA is a specific type of DNA that tumour cells release into the bloodstream after they die. Cancer cells function a lot like normal cells. Just like healthy cells, cancer cells die and new cells are constantly formed to replace the dead cells. Methylation is a process that attaches specific methyl groups on DNA. It determines which fragment of DNA is going to be active - the region which gets methylated is suppressed. Specific methylations in healthy cells make them grow uncontrollably or turn into cancer. ctDNA carries these methylations on their surface and is hence different from normal cell DNA. While the findings are new, the research goes back a few years. The method seems to be based on the liquid biopsy procedure, something that GRAIL inc focuses on. Liquid biopsy, which involves sampling body fluids, mainly blood, to look for disease conditions, is now being used in cancer research. Though it is not really a new concept - we already use amniotic fluid samples to check for developmental abnormalities in foetuses. Currently, liquid biopsies are being used for the early detection of cancer — months before — though they look for cancer-related changes in DNA or genetic mutations that can lead to cancer. This is a tedious task since cancer DNA is present in small quantities in the blood and sequencing the DNA samples takes time. Also, the existing methods could only detect one cancer at a time. On the other hand, focusing on methylation pattern has helped the scientists look for more than one type of cancer with a single test. The dual benefit of this test comes in the form of tissue detection - detecting the tissue where cancer started. Specific methylated regions are present in different body tissues. In a press release, GRAIL’s Chief Executive Officer Jeniffer Cook said: “Our improved methylation-based technology has the potential to address gaps that exist with today’s screening options, which are limited to a few cancer types and only screen for one cancer type at a time. Based on these positive data, we plan to advance the development of our test toward commercialization.” Oncologist Geoffrey Oxnard from Dana-Farber said, “Such assays are a feasible way of screening people for cancer. If the test were in wide use, it could help patients receive more effective treatments.” Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health. For more information, please read our in-depth article on   Cancer: Causes, Types, Diagnosis and Treatment_._