an aggressiver Blood cancer , which mainly affects children, has 15 different subtypes, each associated with a certain result and the reaction to medication, according to a genomic analysis 1 . The work promises to improve treatment - for example, to preserve some children from the toughest chemotherapy regimen and to give others the latest immunotherapies.

This Detailed classification Pay the way for targeted therapies, say researchers, and offers people with T-Zell- Acute Lymphblastic Leukemia (T-All) Hope, which is about 5% of all pediatric cancer. The work published today in Nature could help to predict who is less likely to respond to the treatment and support doctors in the selection of more effective therapies from the start.

“It is a great study that will treat T-All patients a very extensive resource," says Jan Cools, a researcher for leukemenetics at the Flemish Institute for Biotechnology in Ghent, Belgium, which was not involved in research.

a degenerate stem cell

t-All occurs when a mutated stem cell produces large amounts of abnormal T cells in the bone marrow, a type of immune cells. Although the survival rates for T-All have improved with progress in chemotherapy, according to study mitutor David Teachey, a pediatric oncologist and researcher at the Philadelphia children's hospital in Pennsylvania, 15-20% of children and teenagers experience relapses or have forms of illness that do not respond to standard treatment. It is therefore important to find better biological markers who can predict which people with T-All need targeted therapies or new treatment approaches.

In advance, research had identified various subtypes of T-All, but no study was big enough to reliably predict the course of the disease of a person solely due to genetic changes. Therefore, the entire DNA sequence analyzed the entire DNA sequence from both tumor cells and healthy cells of more than 1,300 people with T-All who received the same treatment. The researchers also examined cellular RNA to understand how genetic activity was changed in the cancer samples.

linking of genome and result

The analysis revealed 15 different T-All Subtypes, some not characterized before. Each subtype showed unique genetic changes and gene expression patterns. People with certain sub -types had more likely to have cancer cells in the body after the treatment, which can lead to a relapse of the disease. People with other sub -types were more likely to survive to remain cancer -free, and a subtype had more likely led to a different kind of cancer elsewhere in the body, the researchers found.

The analysis also showed that almost 60% of the genetic changes associated with T-All in DNA sections occur that do not produce proteins, but can influence gene activity . These changes often led to the inappropriate activation of genes and contributed to the development of cancer.

Using genetic and clinical data, the researchers classified T-All after risk level: very high, high, low and very low. This classification could help doctors adapt treatments by recommending stronger chemotherapy or new immunotherapies for high -risk opera and less aggressive treatments for people with less risk, says Cools.

The study attracted participants from the United States, Canada, Australia, Switzerland and New Zealand. Since the genetic history of a person can influence their reaction to the treatment, the results in various populations must be validated, says study mitutor Charles Mullighan, hematologist at the St. Jude Children’s Research Hospital in Memphis.

Research also emphasizes the need to analyze the entire DNA sequence of tumor cells in people with T-All. Although this 'full genome sequence' is not yet widespread due to its costs, Mullighan expects it to become more common in the future. “Studies like this suggest the convincing case that we should increasingly carry out a full genome sequence for this type of leukemia.”