New types of blood cancer discovered in children

New types of blood cancer discovered in children

Acute lymphoblastic leukaemia is a rare disease, but the most common form of cancer in children. Today the treatment is very successful, but requires heavy interventions at the risk of causing many side effects. There is therefore a need to distinguish between different types of acute lymphoblastic leukaemia, in order to adapt the treatment according to the severity of each case, and to detect possible relapse.

Through a detailed study of leukaemia cells from more than 200 children, a research group at Lund University in Sweden has discovered two new types of childhood leukaemia. Using next-generation sequencing technology (NGS), the researchers were able to study the genome of cancer cells, which is how they discovered the new types of cancer.

"Like all types of cancer, childhood leukaemia is caused by genetic mutations in normal cells, which are then transformed into cancer cells. Finding the critical mutations in the diseased cells is an important condition for understanding the mechanisms of the disease and ultimately discovering new therapies", explains Principal investigator and the work is published in the prestigious journal Nature Communications.

Through the relatively new next-generation sequencing method, the researchers were able to examine the changes that occur in cancer cells in greater detail, which is how they discovered the two new types of childhood leukaemia.

"One type occurs when a gene called DUX4, which is normally inactive in blood cells, becomes activated when the gene is relocated in the genome. The second type resembles a previously known type of childhood leukaemia, but is caused by other genetic mutations", says project manager of the study.

Authors describe a subtype characterized by recurrent IGH-DUX4 or ERG-DUX4fusions, representing 4% of cases, leading to overexpression of DUX4 and frequently co-occurring with intragenic ERG deletions. They also identify a subtype characterized by an ETV6-RUNX1-like gene-expression profile and coexisting ETV6 and IKZF1 alterations. 

Previous studies of childhood acute lymphoblastic leukaemia have shown that there are six major groups of acute lymphoblastic leukaemia in children. The discovered two new types, together representing about 10 per cent of all childhood leukaemia, can now be added to these groups.