Rhabdoid tumors trigger an immune reaction in children

Rhabdoid tumors are rare and particularly aggressive, and they originate in the brain and spinal cord. They appear particularly in children aged under 3. The five-year survival rate is low - just 40% compared with 80% on average for all pediatric cancers. The work of Dr. Amaury Leruste, under the supervision of Dr. Franck Bourdeaut from the Pediatric oncology translational research team, RTOP-Inserm U830 at the SIREDO* cancer center at Institut Curie, offers new prospects for treating these cancer tumors. There had been very few studies involving rhabdoid tumors. Until recently, all pediatric cancers were deemed to be "silent", i.e. incapable of causing an immune reaction in young patients. By demonstrating their immunogenicity, this work disrupts the established order.. Their article, to be published soon in the journal Cancer Cell, won the Odile-Schweisguth award for best article.

The steps in the research project

During the first phase of their work, the researchers studied a great number of samples of rhabdoid tumors. They observed that a large portion of the tumors presented inflammatory aspects, which could suggest an immune response.

In the second phase, they analyzed samples of tumor infiltrates from patients, containing cells from the immune system (T lymphocytes). They found that, for the same sample, around 100 T lymphocytes had the same genetic identity. This means that they all came from the replication of a single T lymphocyte. In the presence of an immunogenic body, these cells replicate, and this is known as clone expansion. This observation confirms the immunogenic nature of rhabdoid tumors.

Moving towards clinical trials

The team validated also these results in animal models and demonstrated that in the event of tumor relapse, the immune system could again defend itself through the immune memory.

Scientists are now seeking to better understand the mechanism responsible for the immune response, and how the tumors might escape it. They want to be able to carry out clinical trials quickly in order to explore immunotherapy. According to Dr. Amaury Leruste, "this method, combined with surgery, could avoid radiotherapy and thus a certain number of long-term after-effects."

* Care, Innovation & Research in Childhood, Adolescent and Young-Adult Oncology.

A tribute: Dr. Odile Schweisguth at Institut Curie

Dr. Odile Schweisguth is considered to be the founder of pediatric oncology in France and throughout the world. In France, she created one of the world's first "childhood oncology" departments and took part in the creation of Institut Curie's pediatrict oncology department, which opened in 1977. The achievement of the Odile Schweisguth award for best article for work conducted at Institut Curie therefore takes on special significance.