Questions remain about how to interpret MCED test results. Only some blood tests can determine which organ the cancer is actually in. Lab tests must be done on potentially cancerous tissue to confirm the diagnosis, but you cannot biopsy a person’s whole body. False positives remain a problem for the entire field of cancer screening, which, by design, involves sifting through piles of health tests to find cancer. Gallery – MCED furthest all the way to widespread use – incorrectly identified 57 healthy blood samples as cancerous in the above study.
There’s also the risk of jumping the gun – some cancers never become invasive or life-threatening, but early detection can lead to a treatment as harsh as chemotherapy. Some data suggests that cancers of less concern actually appear in the bloodstream less often, which may limit the effect of these tests.
The NIC trial will help determine how to interpret blood test results for cancer, and provide a standard approach to launching cancer screening studies as companies flood the field with new tests.
“I don’t think most companies tend to want to compare their tests head-on,” he says. Timothy Rebek, a professor of cancer prevention at Harvard University. “It’s expensive and difficult. So someone else, a neutral party like the National Cancer Institute, has to do it.”
Rebbeck believes that the blood tests the vet will run in the new trial will prove very useful in cases of pancreatic, liver and ovarian cancers, which kill so much and have no other form of screening. However, longer trials are needed to confirm whether the time bought by these blood tests saves lives.
But Rebbeck is optimistic about the ultimate goal of the Cancer Moonshot: “It seems to me that it’s very realistic to think that we can cut death in half,” he says.