DNA test can detect 18 forms of cancer at early stages, scientists say
Scientists have developed a simple DNA test that can identify 18 early-stage cancers that experts say could be a medical “game changer.”
Cancer is responsible for one in six deaths worldwide, but early detection can significantly improve outcomes. Existing screening tests have disadvantages, including invasiveness, cost, and low accuracy levels for early-stage disease.
Now American researchers have designed a test that analyzes proteins in the blood and can detect 18 early-stage cancers, representing all major organs in the human body.
Specific blood proteins could already be used for early detection and monitoring, but until now tests have lacked sensitivity (accuracy in picking up people with cancer) and specificity (accuracy in excluding people without cancer), the researchers said.
The team from US biotech company Novelna said their test outperformed others that relied on tumor DNA in the blood, and had “much greater sensitivity” than the Galleri test being trialled by the NHS in Britain.
By looking at proteins in blood plasma, the experts were able to distinguish cancer samples from normal samples, and even distinguish between different types of cancer “with high accuracy,” they said. The study also found evidence that signals from cancer proteins were likely sex-specific.
The team wrote in the journal BMJ Oncology: “This finding provides the basis for a multi-cancer screening test for the early detection of 18 solid tumors covering all major human organs of origin for such cancers at the earliest stage of their development. with high accuracy.”
They added: “This could reform screening guidelines, making this plasma test a standard part of routine checks.”
“These findings pave the way for a cost-effective, highly accurate screening test for multiple cancers that can be implemented on a population-wide scale.”
Blood plasma samples were collected from 440 people diagnosed with 18 different types of cancer and from 44 healthy blood donors.
The team then identified early-stage cancer proteins and where they originated in the body “with high accuracy.”
The team wrote: “At stage I (the earliest stage of cancer) and at a specificity of 99%, our panels were able to identify 93% of cancers in men and 84% of cancers in women.
“Our sex-specific localization panels consisted of 150 proteins and were able to identify the tissue of origin of most cancers in more than 80% of cases.”
Analysis of the plasma protein also showed that almost all of them were present in very low concentrations. This demonstrates the importance of low-level proteins to pick up pre-cancerous and early-stage diseases before a tumor has had time to cause significant damage, the team said.
However, the team said their relatively small sample size meant further research was needed in larger groups of people.
Dr. Mangesh Thorat, from the Center for Cancer Prevention at the Wolfson Institute of Preventive Medicine, who was not involved in the study, said there were still questions about the test and more studies were needed.
“However, the interesting aspects of this test are a much higher sensitivity for stage I cancers than other comparable tests in terms of development and sex-specific performance differences that are biologically and clinically relevant,” he said.
“If test performance in future, well-designed sequential studies comes anywhere close to what this preliminary study suggests, then it could truly be a game changer.”
Prof. Paul Pharoah, a cancer epidemiology expert at Cedars-Sinai Medical Center who was also not involved in the study, welcomed the findings but urged caution.
“Simple blood tests that can detect many different cancers at an early stage (test is sensitive) and do not produce false positives (test is specific) are a holy grail for early detection,” he said.
“This article reports on the first results of the development of such a test. Although the results are promising, it is far too early to be confident that this test will be useful for the early detection of cancer.”