After osteosarcoma, it is the second most common malignant bone tumor among adolescents and young adults.
- 70% of people with Ewing sarcoma are between 5 and 25 years old.
- This malignant bone tumor mainly develops in the pelvic bones, ribs, femurs, fibulas and tibias.
- Nearly 95% of Ewing tumors are due to a genetic alteration, “thus revealing the possibility of immunotherapies targeting these specific tumor proteins”, explains Dr Olivier Delattre, Inserm research director at the head of the unit. Cancer, Heterogeneity, Instability and Plasticity – CHIP.
Ewing’s sarcoma takes its name from the American pathologist, James Ewing, who first described it in 1921. Each year in France, between 80 and 100 cases are diagnosed, with 70% of patients being between 5 and 25 years old, specifies the Gustave Roussy cancer center.
In which parts of the body does Ewing’s sarcoma develop?
This cancer mainly develops in the pelvic bones, ribs, femurs, fibulas and tibias. But it also has a strong invasive power and “it is therefore not uncommon to see other cancerous foci appear in the body, especially in the lungs, skeleton and bone marrow.”, details the Institut Curie. At the time of diagnosis, 30 to 35% of patients already have metastases.
Signs of bone cancer to spot
Initially, Ewing’s sarcoma progresses silently, without any particular signs. As the tumor progresses, the patient may notice:
- the presence of a mass or swelling in the diseased bone;
- pain, stiffness or tenderness at the tumor site;
- pain that can wake the child from deep sleep;
- a reduction in motor skills, which can lead to difficulty walking;
- weak bones, with a risk of fracture;
- fatigue, weight loss, fever or even anemia.
Treatments for Ewing tumor
“Treatment for Ewing’s sarcoma includes three phases, all of which are important for controlling the disease, achieving remission, minimizing the risk of disease recurrence, and maximizing the chance of recovery with minimal after-effects.”, explains the Gustave Roussy center. It is during a multidisciplinary consultation meeting that the doctors decide precisely on the strategy to follow. In most cases, localized forms are treated with an initial combination of chemotherapy and surgery, which aims to remove the entire portion of the diseased bone and then reconstruct it. In rare cases, when local invasion of the tumor is significant, amputation may be necessary. Then comes postoperative chemotherapy, and sometimes radiotherapy.
When the tumor is localized, the chances of cure are around 70%. On the other hand, metastatic forms have a more unfavorable prognosis, with risks of relapses.
95% of Ewing tumors are due to a genetic alteration
Researchers at the Institut Curie discovered that “almost 95% of Ewing tumors are due to a genetic alteration: most often, it is a translocation which occurs between chromosomes 11 and 22 and results in the synthesis of an abnormal protein EWS-FLI- 1”.
“The existence of these particular genetic mutations is found in many pediatric cancers, thus suggesting the possibility of immunotherapies targeting these specific tumor proteins., explains Dr Olivier DelattreInserm research director at the head of the Cancer, Heterogeneity, Instability and Plasticity unit – CHIP (Institut Curie/INSERM/University of Paris). This discovery could prove revolutionary for the management of childhood tumors which today constitute the 2nd cause of mortality among those under 15 years old.” THE first results of the work are all the more encouraging since scientists have shown that “hundreds of these neogenes can be detected in various cancers characterized by oncogenic chimeric transcription factors”, specifies Inserm. “The high specificity and recurrent expression of these peptides in a wide variety of childhood sarcomas make them promising therapeutic targets for the development of immunotherapies in the treatment of pediatric cancers.”
