Soft-tissue cancer (sarcoma)


Soft-tissue sarcoma is a tumor that develops in the soft parts of the body. It represents 8% of cancers in children, or around 120 cases per year in France.

Move on directly to section

What is uveal sarcoma?

In pediatrics, most soft-tissue masses are not cancerous, but rather malformations, abscesses or infections. Truly cancerous tumors are known as soft-tissue sarcomas. They can develop at any age and in any part of the body, particularly in the muscles, nerves and vessels, or in the fat surrounding bones.

In children, some 60% of these soft-tissue sarcomas are rhabdomyosarcomas and 40% are other types of sarcoma. These cases represent 8% of cancers in children, or some 120 cases per year in France.

Sarcomas are often revealed due to a rapidly developing mass, which is painless at first. The tumor may sometimes obstruct an organ, such as the urinary, respiratory or digestive tract. It then produces symptoms related to blockage of these tracts. When the sarcoma has produced metastases, the patient may also be feeling generally unwell.

The average age of discovery of rhabdomyosarcoma is 5, with two peaks at age 3 and after the age of 10. For other types of sarcoma, the average age is 9.

To reach a diagnosis, the physician uses ultrasound and, above all, an MRI in addition to clinical examination. The diagnosis is confirmed by taking a small sample of the mass (biopsy) through the skin or during minor surgery. Anatomopathologists working in laboratories then analyze this sample using special coloring and molecular tests. Part of the sample is kept in order to carry out molecular analyses at a later date, to confirm or refute the diagnosis.

Once the diagnosis is established, an extension review is carried out to measure the extent of the disease. The exams conducted depend on the diagnosis, and may include pulmonary scan, scintigraphy, PET scan of the entire body, or bone-marrow test.

The treatment obviously varies depending on whether the patient is a newborn or an adolescent. It usually includes chemotherapy for several months, depending on the characteristics of the tumor and the condition of the child. After a few sessions, local treatment is often considered, comprising surgery (removing the tumor) and/or radiotherapy. The treatment usually lasts between 6 and 12 months.


Treatment of soft-tissue sarcoma at Institut Curie

Institut Curie is an expert center for sarcoma in children and adolescents.

Chemotherapy and radiotherapy take place at Institut Curie, which offers a complete, cutting-edge technical platform. Modern radiation techniques, such as IMRT, tomotherapy and proton therapy allow for targeted radiation, even in small children.

Institut Curie collaborates with the pediatric hospitals of the APHP, Necker and Robert-Debré, in particular for organizing surgery.

In the Pediatrics department, physicians and caregivers do everything to provide children with the best possible environment. Adolescents and young adults, who have different needs, also have a dedicated unit.


Our Research

In recent years, molecular knowledge on rhabdomyosarcoma has made great strides. Recently, a genetic alteration that helps distinguish cases of rhabdomyosarcoma with a positive prognosis from those with a poor prognosis appears to have been identified. It seems to be more significant than the morphological characteristics for distinguishing them. This new classification helps to avoid aggressive treatments and their consequences for children with standard-risk tumors and to intensify these treatments when there is a high risk of recurrence.

At Institut Curie, several basic research teams are working on certain types of sarcoma. They are seeking to understand these diseases better in order to improve their treatment. These include the Somatic Genetics team of Dr. Olivier Delattre and the Pediatric Oncology Translational Research laboratory (RTOP) of Dr. Gudrun Schleiermacher.

Find out more about Dr. Olivier Delattre’s Somatic Genetics team


Find out more about Dr. Schleiermacher’s RTOP laboratory 


Where possible and justified, children suffering from tissue sarcoma may be included in a clinical trial.