The researchers found that of more than 6,600 apparently healthy people aged 50 and over, the blood test detected a possible ‘signal’ of cancer in about 1%. When these people had more extensive tests, cancer was confirmed in 38%. Experts called the findings an “important first step” in seeing how the so-called early detection test for multiple cancers might fit into real-world care. “This is not ready for the first time,” said study co-author Catherine Marinac, a researcher at the Dana-Farber Cancer Institute in Boston. But if further studies confirm the blood test’s usefulness, he said, it could be a “game changer.” The findings come from a study called Pathfinder, which is being conducted at several medical institutions in the United States to evaluate the Galleri blood test. It’s one of several blood tests being developed by several companies — all with the goal of providing “one-stop” screening for multiple cancers. The Galleri test can screen for more than 50 types of tumors, including many that currently have no routine screening tests, such as pancreatic, liver and ovarian cancers. But while this may sound like a panacea, there are pitfalls to any cancer screening. One is the risk of a false positive that leads to further, possibly invasive, tests only to find that there is no cancer — and all the stress and expense that could come with that. It’s important, Marinac said, to study not only how well early detection tests for multiple cancers perform, but also what happens when they’re part of real-world care. And ultimately, he said, a screening test should save lives. Much more research will be needed to see whether cancers detected by these blood tests are less likely to be fatal. The Galleri test is made by GRAIL, a California biotech company that is funding the Pathfinder study. Galleri and similar tests under development work on one basic premise: They look for biological “signals” that cancer may be present, such as pieces of DNA shed by cancer cells into the bloodstream. Blood tests can also predict where in the body the potential threat is located, so doctors can decide which follow-up tests – such as imaging, endoscopies or biopsies – should be used. The current findings are based on more than 6,600 adults age 50 and older without known cancer. Just over 1% tested positive for the Galleri test and 38% of them were eventually diagnosed with cancer. Of all patients with a positive blood test, more than 90% had more than one imaging test, while half had more than one invasive test — although many of those were performed on people who were found to have cancer. The “diagnostic odyssey,” Marinac said, was greater for people who were ultimately not diagnosed with cancer: In those cases, doctors were typically reluctant to stop diagnostic workup after initial tests showed no cancer. So for these patients, the diagnostic “analysis” took an average of 79 days – meaning half had a longer wait. Importantly, the researchers found that when the blood test showed no cancer, it was correct 99% of the time. The results were presented Sunday at a meeting of the European Society of Medical Oncology in Paris. Studies published at meetings are generally considered preliminary until they are published in a peer-reviewed journal. “This is very exciting technology,” said Dr. Ruth Oratz, a medical oncologist at NYU Langone Perlmutter Cancer Center in New York. Orage, who was not involved in the research, said it would be “fantastic” to screen for multiple cancers with a single blood draw. “But,” he emphasized, “we’re not there yet.” Cancer screening is complex, Oratz noted. Depending on their risk factors, some people need to start screening earlier or have more frequent or different types of tests, for example. It’s not yet clear, Marinac said, who should be screened with any early detection test for multiple cancers, how often it should be done, or whether the frequency should vary depending on people’s risk factors. Both experts stressed that people should continue with existing screening tests for diseases such as breast, cervical and colon cancer. Talk to your doctor, Oratz said, about what screenings you should have. At this point, no early detection test for multiple cancers has been approved by the US Food and Drug Administration. Galleri is available to doctors to order as a “laboratory-developed test” — which the FDA has historically not regulated, according to the US National Cancer Institute. However, patients will likely have to pay for the test, the institute says, and possibly any diagnostic tests used to follow up on a positive result. More information The US National Cancer Institute has more on early detection tests for multiple cancers. SOURCES: Catherine Marinac, PhD, assistant professor, medicine, Harvard Medical School, assistant professor, medical oncology, Dana-Farber Cancer Institute, Boston. Ruth Oratz, MD, medical oncologist, NYU Langone Perlmutter Cancer Center, New York. presentation, European Society for Medical Oncology, Paris, 11 September 2022, abstract From your website articles Related articles around the web
