Research shows that blood tests can use DNA to find the eight most common cancers


Scientists have made significant progress in developing cancer blood tests that recognize tumors long before people become aware of the symptoms.

For new tests that are both susceptible to mutant DNA floating freely in the blood and to cancerous proteins, positive results are achieved in about 70% of the eight most common cancers when tested in more than 1000 patients.

In the future, this test may be used for routine screening programs to significantly increase the proportion of patients treated early, when cancer usually occurs in routine scans.
“The combination of early detection with selected biomarkers has the potential to change the way we screen for cancer and is based on the same principle of using drugs to treat cancer,” said Nickolas Papadopoulos. Johns Hopkins University and senior author’s thesis.

The test can also determine the form of the cancer the patient is suffering from, a goal previously not met with blood tests for cancer.
It works by detecting free-floating mutant DNA that is released into the bloodstream by dead cancer cells. This test screens for errors in the 16 genes that frequently mutate in different types of cancer. Patient blood was also tested on eight known protein biomarkers that were considered to differ to varying degrees depending on where the tumor is located in the body.

In the blood samples of 1,005 patients, 33% to 98% of the cases were detected. Ovarian cancer is the easiest to detect, followed by liver, stomach, pancreas, esophagus, colorectal cancer, lung cancer and breast cancer.

The sensitivity of five types of cancer (ovarian cancer, liver cancer, gastric cancer, pancreatic cancer and esophageal cancer) that currently have no screening test ranges from 69% to 98%.

When tested on 812 healthy control subjects, only seven false-positive results were produced. Kenneth Kinzler, a professor of oncology at Johns Hopkins and coauthor of the paper Kenneth Kinzler, said: “Very high specificity is essential because false positive results can make patients unwanted Innovative follow-up testing and procedures to confirm the presence of cancer.

Patients in the trial had non-metastasized – ie, localized – stage I to III cancers. Experts point out that those with the lowest rates of morbidity are those with the lowest rates of disease and those with no symptoms yet.
Paul Pharoah, a professor of cancer epidemiology at Cambridge University, said: “There are some important caveats first of all, 80% of cancer evaluations are second- or third-stage cancers – quite advanced, proving that testing can detect advanced cancers is not Means testing will help detect early symptomatic cancers, let alone pre-symptomatic cancers, with only 40% of the cancer in the first phase of the study. ”

Chris Abbosh of the UCL Cancer Institute described the work as exciting. “This is one of the first studies to use protein biomarkers and circulating tumor DNA as a screening tool and to cross this tool across a range of cancer types in a large number of patients.

Although the current test does not detect every type of cancer, it identifies many cancers that may not be detected. “Many of our most promising cancer treatments today benefit only a small number of cancer patients and we think of them as major breakthroughs and if we are to make progress in early cancer detection we have to start research in a more realistic way and realize there is not any The test detects all cancers, “said Bert Vogelstein, a professor of oncology at Johns Hopkins University.


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