Osteosarcomas and Ewing tumors


Osteosarcomas are aggressive cancers that develop from a bone. They occur mainly in young people between the ages of 10 and 20.

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Osteosarcomas and Ewing tumors: what are they?

Osteosarcomas develop from a bone. The majority of these tumors occur around the knee. Other locations are possible, usually on a long bone. The most common location for metastases is the lung, followed by the other bones. 

Treatment for osteosarcomas, whether localized or metastasized, generally involves three steps.

  • Neoadjuvant chemotherapy (performed before any other treatment) is used to reduce the size of the tumor and limit the propagation of metastases.
  • Local treatment, usually surgery, allows the tumor to be fully excised (or removed) and the affected limb to be reconstructed. In some cases, conservation treatment is not possible, and the limb must be amputated. These orthopedic treatments require the intervention of surgical experts.
  • Adjuvant (or post-operative) chemotherapy is performed, depending on the results of surgery and microscopic examination of the excised tissue.

Treatment lasts approximately nine months. Close monitoring is then required to ensure that there is no reoccurrence or complication. Follow-up consultations, which take place every three months for the first two years and then less frequently, include a clinical exam and appropriate imaging exams.


Ewing’s sarcoma generally develops from a bone and invades the neighboring soft tissues: muscles, fat, nerves, etc. It often develops in the pelvis and spine, but can occur anywhere in the body. Metastasis is possible, mainly to the lungs, bones, and bone marrow. Ewing’s sarcoma most often affects young people ages 13 to 25, but it may also occur in younger children or in adults.

Treatment often incorporates multiple types of therapy:

  • Chemotherapy.
  • Radiotherapy.
  • Surgery.

Although care is adapted to the stage of the disease, the first step is always chemotherapy, to reduce the size of the tumor and limit metastatic propagation. The second step consists of local treatment: surgery and/or radiotherapy. The team may also opt for adjuvant chemotherapy. Certain cases of Ewing’s sarcoma may require high-dose chemotherapy with stem-cell autografting. Post-treatment follow-up uses the same schedule as osteosarcomas.


Treatment for this type of cancer at Institut Curie   

Institut Curie, the birthplace of radiotherapy, has state-of-the-art technical equipment. It is one of only two treatment centers in France offering proton therapy. Its radiotherapy and chemotherapy experts work hand-in-hand. Meanwhile, surgery is performed by expert orthopedic surgeons at Institut Curie partner establishments.

For children, orthopedic surgeries are performed at Necker, Trousseau and Robert-Debré hospitals, with Bicêtre hospital added to the list for visceral surgery.

For adolescents and young adults, orthopedic surgeries are performed at Cochin hospital, while visceral surgeries take place at Foch hospital and the Institut Mutualiste Montsouris.

Since 2013, Institut Curie has offered care for adolescents and young adults in a unit specially designed for their age group. This tailored environment and activities help them make the best of a difficult time.

If an autograft becomes necessary, Institut Curie has a number of beds in sterile rooms.


Research on osteosarcomas and Ewing’s sarcomas 

There is currently little diagnostic information to allow the treatment to be adapted, but a number of studies are underway in the search for markers to refine the diagnosis.

At the same time, new treatments are starting to emerge, and clinical trials are continuing in order to assess their benefit. 

Institut Curie is closely involved in clinical and basic research and is certified as an SFCE center for pediatrics and a NETSARC center for adult sarcomas. It participates in many phase I, II, and III clinical trials within France and Europe, and worldwide.

Current trials include:

  • For osteosarcomas: sarcome 09, Os-thiotepa, and all the early trials.
  • For Ewing tumors: EuroEwing 2012, Combinair, and all the early trials.


In addition, a number of Research Center teams are working on these tumors, including Dr. Olivier Delattre’s team.