What are soft tissue sarcomas?

In pediatrics, soft tissue sarcomas are cancers that can develop, as their name suggests, in the skin, muscles, nerves, vessels or fat around bones. They are rare, accounting for 6% of pediatric cancers¹ , or around a hundred patients a year in France. They fall into two categories: "rhabdomyosarcomas" (60%), the most common form of soft-tissue sarcoma between the ages of 0 and 15 (although they can occur at any age, from newborns to young adults), and "non-rhabdomyosarcomas" (40%). The latter constitutes a highly heterogeneous group of over 30 different diseases.
The average age of discovery of rhabdomyosarcoma is 5, with two peaks at age 3 and another during adolescence² . For other sarcomas, age at diagnosis varies widely. Among non-rhabdomyosarcoma soft tissue sarcomas, infants and newborns are more likely to have specific types such as rhabdoid tumors or infantile fibrosarcoma. Older patients, including adolescents and young adults, are more often affected by synovial sarcoma or malignant peripheral nerve sheath tumors.

Institut Curie is particularly involved in combating all these sarcomas, especially rhabdoid tumors, which are rare and very aggressive non-rhabdomyosarcoma sarcomas. These tumors can affect the kidneys, liver, peripheral nerves, or other soft tissues of the body, and sometimes the central nervous system in very young children. Institut Curie has a state-of-the-art research laboratory dedicated to this disease.

Risk factors soft tissue sarcomas

In roughly 80 to 85% of cases, the exact cause of soft tissue sarcomas is unknown. However, several genetic syndromes can increase the risk, such as Li-Fraumeni syndrome, neurofibromatosis type 1, Costello syndrome, Beckwith-Wiedemann syndrome, DICER1 syndrome, and Noonan syndrome. A genetic counseling session is routinely offered to families to address these risks.
 

[1] Registre National des Ophthalmological cancers (RNTSE / RNHE)

[2] Les rhabdomyosarcomes (RMS) - Info Sarcomes