The Gali test, manufactured by the American pharmaceutical company Grail, can detect fragments of cancer DNA that have broken away from the tumor and are circulating in the blood. A blood test for more than 50 types of cancer could help speed up diagnosis.
This was reported by the BBC.
Test results in the US and Canada show that the test was able to detect a wide range of cancers, three-quarters of which have no screening program. The study monitored 25,000 adults over the course of a year, with nearly one in 100 receiving a positive result. In 62% of them, cancer was later confirmed.
Dr. Nima Nabavizadeh, associate professor of radiation medicine at Oregon Health & Science University, said the data shows that the test could “fundamentally change” their approach to cancer screening. He explained that it could help detect many types of cancer “earlier, when the chances of successful treatment or even recovery are greatest.”
The blood test correctly ruled out cancer in more than 99% of those who received a negative result. The test also correctly identified the origin of the cancer in nine out of ten cases. When combined with breast, bowel, and cervical screening, this increased the total number of cancers detected sevenfold. Importantly, three-quarters of the cancers detected were ones that were not covered by screening programs. These included ovarian, liver, stomach, bladder, and pancreatic cancers.
These impressive results suggest that blood tests may ultimately play an important role in the early diagnosis of cancer. However, scientists who were not involved in the study say that further evidence is needed.
The main results of the study will be presented at the European Society for Medical Oncology congress in Berlin on Saturday, but the full information has not yet been published in a peer-reviewed journal. Much will depend on the results of a three-year study involving 140,000 patients from the National Health Service in England. They will be published next year.