Medical technologists have produced an non-invasive test for cancer. The test is said to be so straightforward that cancer detection could become a simple and rapid part of a routine check-up. The new approach takes the form of a “liquid biopsy”. A biopsy is a medical test designed to determine the presence or extent of a disease (such as cancer). Most biopsies require an intervention and they are performed by a surgeon. Once a sample of tissue has been taken it is examined under a microscope by a pathologist, using a histological stain, and it may be subject to additional chemical testing.
The alternative approach is based on a blood test. Here a medic takes a blood sample, and an instrument is used to assess the blood for fragments of DNA. Tumors shed DNA into the bloodstream and this genetic material can be detected using very sensitive tests.
The complexity in creating such a test is with the ability to differentiate between the DNA shed by cancerous cells when they die, in blood plasma, from the DNA that is naturally present from other cells. This has been made possible through advanced sequencing and this is the basis of the method developed by Dr Pedram Razavi at the Memorial Sloan Kettering Cancer Center. In tests, The Guardian reports, the researchers were able to scan “regions” of the genome up to 60,000 times to look for 508 specific genes that signify cancer. This by using a device called the MSK-IMPACT™ diagnostic test machine.
With the tests, 124 patients with advanced breast, lung, and prostate cancers were sampled and their blood screened using the new, high-intensity genomic sequencing method. In 89 percent of the patients, at least one genetic change detected in the tumor was also detected in the blood.
The new approach for cancer detected was presented at an international cancer conference, organized by the American Society of Clinical Oncology, which took place in Chicago at the start of June 2017.
