A new test for brain tumors looks for DNA mutations in blood and urine

In an ongoing effort to detect all forms of cancer early, researchers are making important intrusions in urine and blood tests to detect the disease. British scientists have identified promising new possibilities in this area and demonstrated the first test to detect small DNA mutations released by the death of tumor cells in body fluids.

Both blood and urinalysis have emerged as breakthrough diagnostic tools for cancer, and a series of recent studies showing how to analyze these body fluids to detect biomarkers that represent different types of cancer. There is a study of.This includes gene mutations that signal Bladder cancer also Prostate cancer, A trio of proteins that indicate pancreatic cancer And other biomarkers Lung cancer through urine..

In June, there was evidence that this type of technology was expanding to include brain tumors. Similarly, this is a very early stage of research, Promising studies have shown How genetic microRNAs produced by brain tumor cells are detected in urine samples. Today, a team led by scientists at the University of Cambridge has made another important discovery in the same field.

The team’s technology focuses on what is called cell-free DNA (cfDNA). This is a small piece of mutant DNA that is released into the bloodstream when a cell dies. For dying tumor cells, these mutations may be the same as those found in primary tumors, increasing the likelihood of using blood or urine tests as a screening tool for cancer.

But what makes things difficult with brain tumors is the blood-brain barrier, which prevents fragments from entering the blood. CfDNA, which has the same mutations as the original tumor, is also found in body fluids, albeit at low levels. The challenge was to develop tests that were sensitive enough to find them.

Cambridge researchers have taken some early interim steps to overcome this problem. Their study began with eight patients with suspected brain tumors based on MRI and provided blood, urine, and cerebrospinal fluid samples at the beginning of the study, along with a brain tumor biopsy. This allowed the team to study DNA and find out where it was in the strand to look for mutations in small amounts of cfDNA in urine and blood.

In tests developed to look for these mutations, tumor-specific cfDNA in 10 of 12 blood samples, 10 of 16 urine samples, and 7 of 8 cerebrospinal fluid samples. Has been proven to be able to detect.

In parallel with this test, the team has developed another test that does not require prior knowledge of which mutations to look for. This means using whole-genome sequencing to analyze all cfDNA from brain tumors from 35 glioma patients, with samples from 27 subjects with non-malignant encephalopathy and 26 subjects. It was also taken from a healthy control.

The cfDNA found in blood and urine samples from patients with brain tumors was different in size from healthy controls. This data was entered into a machine learning algorithm, which was less accurate than the first approach, but was able to better distinguish between urine samples from patients with brain tumors and healthy subjects. However, the advantage is that it is cheap and easy and does not require a tissue biopsy.

Although the technology is still in its infancy, the results of the research open up some exciting possibilities. The team envisions a test that can be used to screen high-risk patients who are prone to recurrence because the brain tumor has been removed. These patients usually undergo MRI scans and biopsies every few months to monitor irregularities, but blood or urine tests may offer a much easier option.

Researchers then plan to compare the effectiveness of the test with MRI to see if recurrent tumors can be detected at the same rate, or perhaps earlier. Then they want to start adapting this technology to clinical use, which they say can happen sometime within the next decade.

“We believe that the tests we have developed can detect recurrent gliomas early and improve patient outcomes in the future,” said study author Richard Mare. “When I talk to my patient, I know that a three-month scan is the focus of concern. If you can provide regular blood and urine tests, you can not only detect recurrence early, but also your patient’s. You can also do good things for your mental health. “

The study was published in the journal EMBO Molecular Medicine..

sauce: University of Cambridge