Weizmann Institute reveals: Blood tests for cancer diagnosis - Successful alternative

A new scientific development may lead to blood tests for cancer diagnosis: Weizmann Institute researchers have located genetic changes in the blood of cancer patients, which may represent a "seal" that will enable early diagnosis of various diseases and cancerous tumors - with a simple blood test. The research findings are published in the scientific journal Nature Biotechnology.
Cancer is the world's leading cause of death, even before heart disease, and the diagnosis is often made too late when the tumor has already spread and the metastases cannot be destroyed. The currently accepted methods for detecting cancer are often invasive or very expensive and inaccessible. For example, taking a biopsy during surgery or using a long needle can be painful and sometimes even involves a certain risk.
Imaging tests such as MRI or PET CT also rely on expensive and cumbersome equipment that is not available everywhere. Therefore, effective blood tests may be a successful alternative. "It's not just about convenience," says the head of the team of researchers from the disease for immunology and biological regeneration at the Weizmann Institute, Dr. Efrat Shema.
The idea of ​​diagnosing cancer through blood tests is based on the fact that the byproducts of cell destruction are floating in our blood fluid: DNA segments and proteins derived from dead blood cells. When cancer develops in the body, fragments of DNA and proteins originating from dead tumor cells also float in the blood fluid. Various blood tests for cancer diagnosis are currently in advanced stages of development, but most of them suffer from significant shortcomings.
The first generation of these tests relied on the identification of genetic mutations that are very difficult to detect in blood tests, since they constitute only a fraction of the genetic material secreted into the blood; Moreover, the mere existence of the mutations does not necessarily indicate the development of cancer.
The new generation of blood tests focuses on a different type of data: epigenetic mechanisms, i.e. changes in the cell genome that do not involve changes in the DNA itself, for example, various chemical tags that stick to the DNA molecule and thus affect gene expression. But even these methods have notable drawbacks: some tests require a large amount of blood, while others rely on the detection of only one type of epigenetic change, that is, a change in gene function, and therefore their results are not very reliable.
In the current study, the researchers used Dr. Shema's method to compare the cellular particles called nucleosomes from the blood of 30 healthy volunteers with those of 60 colon cancer patients at different stages of the disease. The scientists identified a fundamentally different genetic pattern in each of the groups. Using a small amount of blood, they were able to map six genetic changes associated with cancer and even identify a variety of other known cancer markers in the samples, including protein fragments from dead tumors that cannot be detected by conventional technologies.
Using artificial intelligence algorithms, the scientists analyzed the large database obtained from the two groups, and made comparisons between the blood samples of healthy people and those of ten pancreatic cancer patients. "Our algorithm knew how to distinguish between groups of healthy people and cancer patients with an accuracy of 92 percent - an unprecedented level of confidence for this type of testing," says Dr. Shema.
For now, this is only a preliminary study with a very small number of subjects, but if these findings are replicated in larger experiments, the way will be paved for the development of a multi-parameter blood test for cancer detection based on a blood sample of less than one milliliter.
In the current study, conducted under the leadership of research students Vadim Padiuk and Nir Erez, the researchers aimed to develop a new approach that would make it possible to reliably diagnose cancer based on a small amount of blood. To this end, they based themselves on a method that uses a device called a fluorescence microscope, which makes it possible to accurately map gene function on the basis of a very small sample.
Tests of this type are expected to advance the world of personalized medicine as well, since the multitude of data revealed in the test is expected to allow optimal treatment to be tailored to each patient.
"We have presented proof of the feasibility of our method, and now we have to see if the findings will also be reproduced in the clinical trials," concludes Dr. Shema. "In the future, this method may make it possible to diagnose not only different types of cancer, but also other diseases that leave traces in the blood, such as autoimmune diseases and heart disease".