Blood tests have become a popular study focus among scientists seeking mechanisms for early detection of cancer. Researchers have come up with a number of tests in recent years that examine a variety of components of blood, among them types of blood cells, proteins, and the presence of mutated DNA. Most of the tests are specific to particular cancers and vary in their levels of accuracy.
In this release, a team at the University of Bradford heralds the increasing accuracy of a test that measures the response of white blood cells exposed to ultraviolet light. The test, called TumorScan, uses an automated cell reader designed by a Paris-based company, IMSTAR, to examine thousands of cells from any one sample, and the researchers say that they have found the process can detect the presence of any type of cancer with more than 90% success. IMSTAR has now licensed the university team’s technology and plans to bring the text to market some time in the future.
The release touts the potential benefits without addressing some real concerns: Technology like this is enabling us to find more and more cancers at an earlier stage, but we are often unable to differentiate between the ones that need to be treated and those that can be monitored or ignored. While the news release didn’t need to go into great detail about this, it should at least acknowledge the downsides.
Finding cancer at an early stage via a blood test may improve survival rates, and reduce the need for invasive biopsies. However, it’s important to keep in mind that all cancer screening tests carry the risks of false-positives, false-negatives and overdiagnosis and treatment of non-growing or slow-growing cancer.
Although the release’s lead emphasizes efforts to bring this blood test to market, there are no cost estimates in the text. A source affiliated with the company that licensed the test is quoted as valuing the maintenance of “affordable cost,” but we have no idea what that might mean.
The release states that a modified version of the original test can identify individuals with cancer more than 93% of the time.
It’s unclear what the 93% success rate means in this context. Is that the sensitivity? What is the false positive rate? Why these terms matter.
The release needed to provide more information on the risks that arise with cancer screening tests–for example, of being told you have cancer when you do not; or the opposite, being told you’re cancer-free when you actually have cancer. There is also the risk of overdiagnosis — finding and treating non-growing or slow-growing cancer that doesn’t need to be treated.
The release needed more about the limitations to this research. It appears the test has only been run on people where their cancer status is known, for example. A prospective trial needs to be conducted. Also, it’s not known whether earlier diagnosis will make any difference or cause more harm than good.
Blood tests to detect cancer would provide a significant opportunity to find cancers at an early stage, when they can possibly (but not necessarily) be successfully treated. But, as we mentioned, the risk of overdiagnosis and overtreatment needs to be acknowledged.
While it is not clear who is funding this latest study, the company, IMSTAR, which has licensed the test, identifies the University of Bradford as a “partner” on its website. Additionally, the PI quoted most extensively in the release appears to co-own a 2010 patent for a similar test.
The news release did attempt to explain alternatives. More could have been said about this, but we found it sufficient for a satisfactory rating:
Professor Anderson said: “This test is different from other universal cancer tests being developed, because it is not looking for a specific biomarker or mutation. This is a generic test for cancer in an individual, regardless of the underlying mechanism that’s causing their cancer.”
The text offers only a general statement at its end indicating that work to develop the test will continue. Ideally the release would have explained that a prospective trial is still needed.
The release establishes what makes this test unique.
The text exercises appropriate caution, describing the blood test as a “potential” tool.