The US is launching a trial for blood tests that promise to catch cancers earlier
Most cancers cannot be detected before symptoms appear. Tools like mammograms or pap smears are the exceptions, not a rule. Numerous companies have developed single tests that can detect multiple types of cancer in blood taken from patients’ arms. This has been done to improve detection. To test the effectiveness of these tests, a nationwide trial is being launched in the US.
In a speech on Monday in Boston, President Biden highlighted these new blood tests and the upcoming trial as central to the Cancer Moonshot–a federal push to halve US cancer deaths in the next 25 years. Biden’s speech came on the 60th anniversary of President John F. Kennedy’s speech pledging to bring a man to the moon and back–the inspiration behind this latest moonshot.
The new trial, run by the National Cancer Institute, will begin enrolling participants in 2024 and test how effective various blood tests are at spotting cancer in 24,000 healthy patients over four years. If the findings seem promising, a clinical trial almost 10 times as large will commence.
Most multi-cancer early detection tests (MCEDs) look for tumor cells that have exploded after the immune system attacks them. The bloodstream can detect cancer if it is found in the debris from dead tumor cells. A biopsy is performed if the imaging confirms the finding.
Currently, only one of these tests are being used in the US. The Galleri, which claims to detect over 50 cancers, is available with a prescription for $949. It is not covered by most insurance plans because it has not been approved by the FDA. New data released by its developers shows that the test caught cancer in 35 people out of a pool of about 6,600 believed to be healthy–and 26 of the cases it caught were cancers not routinely screened for.
Questions remain about how to interpret MCED test results. Only blood tests can identify the organ in which the cancer is located. To confirm a diagnosis, lab tests must be performed on potentially cancerous tissue. However, you cannot biopsy an entire body. False positives are still a problem for all aspects of cancer screening. This involves sorting through a lot of healthy tests in order to find cancer. Galleri–the MCED furthest along the path to widespread use–incorrectly flagged 57 healthy blood samples as cancerous in the aforementioned study.
There’s always a chance of being too cautious. While some cancers don’t become life-threatening or invasive, others can be detected early and could prompt harsh treatment such as chemotherapy. Some data suggests that less serious cancers are found in the bloodstream, which could help to reduce that problem.
The NIC trial will determine how blood tests for cancer should be interpreted. It should also provide a standard approach for launching cancer screening studies, as more companies flood the field with new testing. I don’t think that most companies want to compare their test results head to head,” states Timothy Rebbeck ,, a Harvard professor of cancer prevention. It’s costly and difficult. So someone else, such as the NCI, .” Rebbeck, thinks that the new trial’s blood tests will be most helpful in cases of pancreatic, liver and ovarian cancers. These cancers are often fatal and require no other form of screening. To confirm if these blood tests save lives, more trials are necessary. Rebbeck is optimistic about Cancer Moonshot’s ultimate goal. “It seems very realistic for me to think we could reduce mortality by half,” he said.
I’m a journalist who specializes in investigative reporting and writing. I have written for the New York Times and other publications.